Công bố Quốc tế lĩnh vực môi trường số 10-2022 sẽ có 17 bài nghiên cứu về quản lý môi trường, 16 bài về môi trường đô thị và 16 bài về môi trường khu công nghiệp. Đặc biệt trong số 16 bài nghiên cứu về quản lý môi trường có bài nghiên cứu với chủ đề "Xác định các chất ô nhiễm hữu cơ có nguy cơ tiềm ẩn về sinh thái và sức khỏe trong môi trường nước: Tiến trình và thách thức” đã được chia sẻ trên tạp chí khoa học Science of The Total Environment, tập 806, phần 3, ngày 1/2/2022.

Trong phần tóm tắt nghiên cứu, các tác giả cho biết, hàng nghìn chất ô nhiễm hữu cơ được thải vào các thủy vực một cách cố ý và vô ý, gây ảnh hưởng xấu đến môi trường sinh thái và sức khỏe con người. Việc sàng lọc các chất ô nhiễm hữu cơ có nguy cơ tiềm ẩn trong môi trường nước là cần thiết để quản lý rủi ro. 

Nghiên cứu nói trên đánh giá các quy trình, phương pháp và công nghệ được sử dụng để sàng lọc các chất ô nhiễm như vậy trong môi trường nước và thảo luận về những thuận lợi và khó khăn trong việc áp dụng công nghệ, bên cạnh những thách thức và hạn chế về kiến thức trong lĩnh vực này. Kết hợp các phương pháp sàng lọc không mục tiêu, sàng lọc mục tiêu và sàng lọc nghi ngờ để tổng hợp danh sách các hợp chất có nguy cơ tiềm ẩn và cho phép phân tích định lượng các hợp chất này. 

Theo các nhà khoa học, công nghệ chuẩn bị mẫu và công nghệ phát hiện ảnh hưởng đáng kể đến kết quả sàng lọc chất ô nhiễm. Số lượng hạn chế của thông tin hóa học và độc chất trong cơ sở dữ liệu cản trở việc sàng lọc các chất ô nhiễm hữu cơ có nguy cơ tiềm ẩn. Máy móc, các phương pháp khả thi cao và các công nghệ khác sẽ làm tăng độ chính xác và thuận tiện của việc sàng lọc các chất ô nhiễm có nguy cơ cao. 

Nghiên cứu này có thể coi là một tài liệu tham khảo quan trọng trong việc sàng lọc các hợp chất ô nhiễm trong môi trường nước và có thể được sử dụng trong việc sàng lọc chất ô nhiễm và quản lý rủi ro trong tương lai.

Dưới đây là Công bố quốc tế lĩnh vực môi trường số 10-2022 với những nội dung chính như sau:

- Xác định các chất ô nhiễm hữu cơ có nguy cơ tiềm ẩn về sinh thái và sức khỏe trong môi trường nước: Tiến trình và thách thức.

- Kết hợp các dịch vụ hệ sinh thái để đánh giá tiến độ hướng tới các mục tiêu phát triển bền vững: Một nghiên cứu điển hình về vành đai kinh tế sông Dương Tử, Trung Quốc.

- Xác định nguồn ô nhiễm nước mặt bằng cách sử dụng thống kê đa biến kết hợp với các thông số hóa lý và kinh tế xã hội.

- Chúng ta biết bao nhiêu về sự đánh đổi trong các dịch vụ hệ sinh thái? Đánh giá có hệ thống các quan sát nghiên cứu thực nghiệm.

- Thực hiện các biện pháp giảm thiểu phát thải ban đầu đối với 1,4-dioxane ở Đức: Các biện pháp này có hiệu lực không?

- Đánh giá về việc sử dụng vi nhựa trong việc tái tạo các kho lưu trữ trầm tích có niên đại.

- Đánh giá tình trạng xả rác bừa bãi trong môi trường đô thị và chính sách: Trường hợp của Bangkok.

- Giảm áp lực mối quan hệ giữa năng lượng nước thông qua quản lý toàn bộ chuỗi cung ứng: Bằng chứng từ phân tích cấp tỉnh ở Trung Quốc.

- Tác động môi trường của chất thải nguy hại và các chiến lược quản lý để dung hòa giữa kinh tế tuần hoàn và tính bền vững sinh thái.

- Cải tiến các quy trình chuỗi cung ứng xây dựng với các chiến lược kinh tế vòng tròn: Một đánh giá tài liệu có hệ thống.

- Mô hình Hệ thống thoát nước đô thị bền vững (SUDS) hỗ trợ ra quyết định: Đánh giá định lượng có hệ thống.

- Thu hồi tài nguyên trong đánh giá vòng đời của xử lý bùn: Đóng góp, độ nhạy và độ không chắc chắn.

- Định lượng lợi ích giảm lượng nước mưa chảy tràn của tán cây đường phố đô thị.

- Đánh giá định lượng mức độ phơi nhiễm với ô nhiễm phân trong môi trường đô thị trên chín thành phố ở các quốc gia thu nhập thấp và thu nhập trung bình thấp với một thành phố ở Hoa Kỳ.

- Pha loãng PAHs tải các chất dạng hạt trong không khí, bụi và sông ở các khu vực đô thị: Một nghiên cứu so sánh (siêu đô thị Tehran, Iran và thành phố Tübingen, SW-Đức).

- Tăng cường giảm thiểu tắc nghẽn màng và loại bỏ các hợp chất hữu cơ dạng vết bằng điện trường trong lò phản ứng vi lọc xử lý nước thải thứ cấp của nhà máy xử lý nước thải đô thị.

- Ảnh hưởng của sự phát triển hút ẩm của các hạt sol khí đô thị xung quanh đối với sự lắng đọng cục bộ và khu vực được mô hình hóa của chúng trong hệ thống hô hấp của con người khỏe mạnh và bị tổn thương COPD.

- Khoảng cách ranh giới sinh thái đang dần thắt chặt tại các siêu đô thị của Trung Quốc: Lấy Bắc Kinh làm điển hình.

- Các tác động đến sức khỏe và các biến thể về mặt không gian của các hạt mịn và các thành phần độc hại điển hình của nó trong năm khu vực đô thị của Trung Quốc.

- Tăng cường xử lý thực vật đối với Kim loại (loid) thông qua các hạt nano ZVI có gai: Một chiến lược làm sạch đô thị với cây cảnh.

- Phân hủy sinh học nước thải ô nhiễm thuốc trừ sâu từ một nhà máy công thức sử dụng giường sinh học quy mô thí điểm.

- Vật liệu quang xúc tác cố định trên các giá đỡ tái chế và vai trò của chúng trong việc phân hủy chất gây ô nhiễm nước: Đánh giá kịp thời.

- Tái chế photphogypsum làm nguồn oxit canxi duy nhất trong sản xuất xi măng canxi sulfoaluminate và hóa rắn phốt pho.

- Sự hấp phụ của một loạt các loại dược phẩm đến vi nhựa polyetylen trong nước thải và quá trình giải hấp của chúng trong chất nền môi trường.

- Những tiến bộ gần đây trong hệ thống phản ứng sinh học màng tăng trưởng gắn liền để xử lý nước thải.

- Đánh giá toàn cầu được thông báo về động học về chất thải của mỏ để loại bỏ CO2.

- Đặc điểm phát thải và khả năng phản ứng của các hợp chất hữu cơ dễ bay hơi từ các ngành công nghiệp tiêu thụ năng lượng cao điển hình ở Bắc Trung Quốc.

- Than sinh học nguyên sinh và được thiết kế để loại bỏ các chất gây ô nhiễm cùng tồn tại trong một số loại nước thải công nghiệp: Một đánh giá quan trọng.

- Một đánh giá quan trọng trong công nghệ đông tụ điện áp dụng để loại bỏ dầu trong nước thải công nghiệp.

- Hiện trạng công nghệ và xu hướng xử lý nước thải công nghiệp: Phân tích bằng sáng chế.

Sau đây là tên và phần tóm tắt các bài nghiên cứu bằng tiếng Anh:

Science of The Total Environment, Volume 806, Part 3, 1 February 2022, 150691

Abstract

Thousands of organic pollutants are intentionally and unintentionally discharged into water bodies, adversely affecting the ecological environment and human health. Screening for organic pollutants that pose a potential risk in aquatic environments is essential for risk management. This review evaluates the processes, methods, and technologies used to screen such pollutants in the aquatic environment and discuss their advantages and disadvantages, in addition to the challenges and knowledge gaps in this field. Combining non-target screening, target screening, and suspect screening is often effective for compiling a list of potential risk compounds and enables the quantitative analysis of these compounds. Sample preparation technologies and pollutant detection technologies considerably affect the results of pollutant screening. The limited amount of chemical and toxicological information contained in databases hinders the screening of organic pollutants with potential risk. Machine learning, high-throughput methods, and other technologies will increase the accuracy and convenience of screening for high-risk pollutants. This review provides an important reference for screening these compounds in aquatic environments and can be used in future pollutant screening and risk management.

Science of The Total Environment, Volume 806, Part 3, 1 February 2022, 151277

Abstract

To promote coordinated development of the global economy, society, and environment, The 2030 Agenda for Sustainable Development of the United Nations (UN) specifies 17 sustainable development goals (SDGs) with 169 nested targets. Studies have shown that a healthy ecological environment and stable ecosystem services (ESs) provide an important foundation for achieving the SDGs. Due to the lack of quantitative methods for assessing the contribution of ESs to SDGs, very few empirical studies have been conducted to examine how knowledge of ESs can guide regional sustainable development. From the perspective of an ES cascade, we proposed a systematic approach for quantifying progress towards environment-related SDGs in terms of ES indicators, based on the Yangtze River Economic Belt (YREB). The scores of multiple SDGs and the SDG Index increased significantly across the YREB from 2000 to 2015, mainly attributed to the improvement of food and water provisioning services. Significant spatiotemporal variation in sustainable development levels was observed between provinces within the YREB. For example, the sustainable development levels in the eastern YREB clearly trailed those in the central and western YREB, and the SDG scores and SDG Index scores declined gradually. Among 11 provincial regions in the YREB, the SDG Index scores of nine provincial regions increased gradually, whereas those of Zhejiang and Shanghai declined. Strengthening the assessment of the ES value for generating more comprehensive ES indicators and applying an integrated ES-based approach for monitoring and comparing the process of local and global sustainable development, are promising areas for future research.

Science of The Total Environment, Volume 806, Part 3, 1 February 2022, 151274

Abstract

Accurate identification of potential contamination sources of river water is a basis for effective pollution control and sustainable water management. Pollution source identification based on physicochemical-parameters-only method may lead to uncertainty and subjectivity. In this study along with hydrochemistry parameters (HPs), socioeconomic parameters (SPs) were considered as an auxiliary in multivariate statistics to achieve a comprehensive assessment on pollution sources with accurate estimates of source identification and apportionment. Fifteen physicochemical parameters were combined with twelve socioeconomic parameters in multivariate statistics to quantitatively assess potential pollution sources and their contributions to river water pollution. Multivariate statistics in the study included regression analysis, principal component analysis (PCA), and absolute principal component score-multiple linear regression (APCS-MLR). Regression analysis between hydro-chemical parameters and socioeconomic parameters indicated that industrial and population growths were the main factors related to ammonium nitrogen (NH4+-N), total nitrogen (TN) contamination, while total phosphorus (TP) was more correlated with domestic discharge and poultry breeding. Based on the results of PCA, four latent factors were extracted for hydrochemistry parameters (HPs) and socioeconomics parameters (SPs), accounting for 68.59% and 82.40% of the total variance, respectively. With integrating the PCA results of the two parameter groups, pollution sources were ranked as industrial effluents > rural wastewater > municipal sewage > phytoplankton growth and agricultural cultivation. Source apportionment in APCS-MLR revealed that industrial wastewater and rural wastewater averagely contributed 35.68% and 25.08% of pollution, respectively, followed by municipal sewage (18.73%) and phytoplankton pollution (15.13%) with relatively small percentage of unrecognized source. It is concluded that socioeconomic parameters assisting hydrochemistry parameters in multivariate statistics can improve the accuracy and certainty of pollution source identification, supporting decision makers to formulate strategies on protection of river water quality.

Science of The Total Environment, Volume 806, Part 3, 1 February 2022, 151229

Abstract

As an important domain of sustainability science, trade-offs in ecosystem services (ES) is crucial for spatial planning to sustainably manage natural resources while satisfying the needs of local and non-local beneficiaries. However, there is still a growing debate in understanding, characterization, and visualization of the trade-off relationships. This paper systematically reviews a total of 473 articles, published in the last 16 years (2005–2020) through 135 academic journals, based on empirical studies conducted in over 80 countries, and led by the researcher from over 50 countries. Trade-off relationships are often visualized as spatial associations of ES, but very few articles have characterized trade-offs as the causal interaction among ES. More than two-thirds of the studies were carried out in temperate and sub-tropical regions, but we depicted an under-representation of the critical ecosystems in tropics. About 90% of the articles were based on funded research but the involvement of government institutions was very low (<10%). Trade-off analysis was based only on biophysical constraints of the ecosystem, as observed in more than 80% of the selected articles, without due regards of the divergence in utility functions of different stakeholders and ecosystem beneficiaries. This study identifies a total of 198 pairs of conflicting ES, of which the trade-off between crop production and carbon/climate services has the highest records of observation (i.e., as identified by 20% of the total studies). Further, this study identifies the major drivers (i.e., ecological and social) and stakeholders (i.e., land users and government agencies) of trade-off in ES, and major gaps in the analytical approach to understand the trade-off relationships. Based on our findings, we have discussed and recommended a number of research trajectories, including trans-disciplinary research considering both biophysical constraints and utility functions, in order to guide the future direction of sustainability science through the creation of win-win scenarios.

Science of The Total Environment, Volume 806, Part 4, 1 February 2022, 150701

Abstract

Since our comprehensive investigation of finished drinking water in Germany obtained from managed aquifer recharge systems in the period 2015-2016, which revealed widespread contamination with 1,4-dioxane, mitigation measures (integration of AOP units, shutdown or alteration of production processes) have been implemented at some sites. In this study, we conducted follow-up tests on surface water concentrations and associated finished drinking water concentrations in 2017/2018, to evaluate the effectiveness of these measures. Our findings demonstrate that the emission mitigation measures had considerably reducing effects on the average 1,4-dioxane drinking water concentrations for some of the previously severely affected areas (Lower Franconia: -54%, Passau: -88%). Conversely, at notoriously contaminated sites where neither monitoring nor mitigation measures were introduced, the drinking water concentrations stagnated or even increased. Drinking water concentrations determined via a modified US EPA method 522 ranged from below LOQ (0.034 μg/L) up to 1.68 μg/L in all drinking water samples investigated. In river water samples, the maximum concentration exceeded 10 μg/L. Effluents of wastewater treatments plants containing 1,4-dioxane (5 μg/L–1.75 mg/L) were also analyzed for other similar cyclic ethers by suspected target screening. Thus, 1,3-dioxolane and three other derivatives were tentatively identified in effluents from the polyester processing or manufacturing industry. 1,3-Dioxolane was present in concentrations >1.2 mg/L at one site, exceeding up to sevenfold the 1,4-dioxane concentration found there. At another site 2-methyl-1,3-dioxolane was still found 13 km downstream of the discharge point, indicating that ethers analogous to 1,4-dioxane should be further considered regarding their occurrence and fate in wastewater treatment and the aquatic environment.

Science of The Total Environment, Volume 806, Part 4, 1 February 2022, 150818

Abstract

Buried microplastics (plastics, <5 mm) have been documented within the sediment column of both marine and lacustrine environments. However, the number of peer-review studies published on the subject remains limited and confidence in data reliability varies considerably. Here we critically review the state of the literature on microplastic loading inventories in dated sedimentary and soil profiles. We conclude that microplastics are being sequestered across a variety of sedimentary environments globally, at a seemingly increasing rate. However, microplastics are also readily mobilised both within depositional settings and the workplace. Microplastics are commonly reported from sediments dated to before the onset of plastic production and researcher-derived microplastics frequently contaminate samples. Additionally, the diversity of microplastic types and issues of constraining source points has so far hindered interpretation of depositional settings. Therefore, further research utilizing high quality data sets, greater levels of reporting transparency, and well-established methodologies from the geosciences will be required for any validation of microplastics as a sediment dating method or in quantifying temporally resolved microplastic loading inventories in sedimentary sinks with confidence.

Science of The Total Environment, Volume 806, Part 4, 1 February 2022, 150952

Abstract

Face mask usage is one of the preventive measures encouraged worldwide to limit the transmission of the SARS-Cov-2 pandemic. Hence, production and mass use of face masks is on the rise due to the pandemic as well as government rules that mandate citizens to wear face masks. However, the improper disposal of face masks has been polluting the environment with enormous hazardous waste. In this study, a face mask littering assessment in an urbanized environment, Bangkok, was carried out. Three streets in the city were selected and observed for face mask littering for 5 h per day for 42 days. Moreover, a questionnaire from 605 participants was recorded to determine mask handling and disposal practices. The study found a total of 170 single-use face masks within a 13.30 km path. Furthermore, the highest (40) and lowest (17) cumulative litter were recorded on Sunday and Monday, respectively. Buffer analysis at 300 m showed 47% of mask litter was found within five mass transit stations, while 15% are within a single street market. Of 605 respondents, 82.15% used a single-use face mask. Surprisingly, most of them (70.58%) disposed of used face masks in regular bins along with their household waste. The results highlight three policy implications to tackle the growing problem: raising awareness, regulation, and provision of bins designed for used face masks in strategic places and supporting innovations and research for eco-friendly face masks.

Science of The Total Environment, Volume 807, Part 2, 10 February 2022, 150876

Abstract

Organophosphate esters (OPEs) are used as additives in various industries. They do not chemically bond with the polymeric structure of materials, so they can stay for a long time and have a very adverse effect on the environment. To analyze the development of the prevalence and concentration of OPEs such as TCEP, TCPP, TDCP, TnBP, TPHP, TBOEP, TEHP, TMP, TCIPP, TDCIPP, TMPP, and TDBPP in water resources, a search between January 01, 2000, to April 08, 2021, was followed by a systematic review and meta-analysis. Among of the 888 articles scanned in the identity step, 58 articles containing 2676 samples, 10 countries, and 4 water types were included in the meta-analysis study. Among all studied OPEs, the concentration of TcrP, TCPP, TDCPP, and TnBP were at the top in water resources, with values >715 μg L−1 and lowest average concentrations were obtained for TDBPP and TpeP with values <0.0004 μg L−1. The most polluted area in terms of the concentration of OPEs in water resources was China. Besides, data analysis showed that there only was carcinogenic risk for China. A Monte-Carlo simulation indicated that although these obtained averages are in the same order of magnitude as the acceptable limit, for both adults and children, 95% of the population is at risk.

Science of The Total Environment, Volume 807, Part 2, 10 February 2022, 150838

Abstract

During the COVID-19 pandemic, wastewater-based epidemiology (WBE) has been engaged to complement medical surveillance and in some cases to also act as an early diagnosis indicator of viral spreading in the community. Most efforts worldwide by the scientific community and commercial companies focus on the formulation of protocols for SARS-CoV-2 analysis in wastewater and approaches addressing the quantitative relationship between WBE and medical surveillance are lacking. In the present study, a mathematical model is developed which uses as input the number of daily positive medical tests together with the highly non-linear shedding rate curve of individuals to estimate the evolution of global virus shedding rate in wastewater along calendar days. A comprehensive parametric study by the model using as input actual medical surveillance and WBE data for the city of Thessaloniki (~700,000 inhabitants, North Greece) during the outbreak of November 2020 reveals the conditions under which WBE can be used as an early warning tool for predicting pandemic outbreaks. It is shown that early warning capacity is different along the days of an outbreak and depends strongly on the number of days apart between the day of maximum shedding rate of infected individuals in their disease cycle and the day of their medical testing. The present data indicate for Thessaloniki an average early warning capacity of around 2 days. Moreover, the data imply that there exists a proportion between unreported cases (asymptomatic persons with mild symptoms that do not seek medical advice) and reported cases. The proportion increases with the number of reported cases. The early detection capacity of WBE improves substantially in the presence of an increasing number of unreported cases. For Thessaloniki at the peak of the pandemic in mid-November 2020, the number of unreported cases reached a maximum around 4 times the number of reported cases.

Science of The Total Environment, Volume 807, Part 2, 10 February 2022, 150812

Abstract

Generating an effective and efficient sustainable drainage philosophy is imperative in alleviating the risk of flooding in a complex UK climate that is categorised by excessive rainfall. The Sustainable Drainage Systems (SuDS) approach offers a revolutionary change in using heightened flow rates and large capacities of water to our advantage, while also disguising the attenuated water into the urbanized environment. This research explores the result of integrating several SuDS devices in management trains with the sole purpose of significantly reducing overall water quantity. It will compare and contrast and prove how SuDS is more dependable than the conventional pipe-based drainage system that is characterized by its ability to remove water to the outflow quickly. Furthermore, in order to determine how a SuDS device is implemented into the natural environment, a case study was conducted at a residential area in Gibside View, Winlaton in Gateshead. The research exhibits how the newly implemented Detention basin had to be retrofitted into the already inadequate drainage system that once lived there; all in thought of alleviating the significant flooding events that were once reported to have occurred prior. As a verification method in terms of effectiveness, a questionnaire was conducted through convenient and purposive sampling at the Case Study location; data was accumulated door-to-door inside a 300 m radius of the detention basin and received about 180 valid responses. The results showed persistence of respondents who detailed flooding events prior to installing the Detention basin, who then recognised a fundamental change in the minimization of water quantity and flooding issues. The results of this research showed why Detention Basins continue to be identified as one of the most successful water reduction-based SuDS devices available for development nationwide implementation.

Science of The Total Environment, Volume 807, Part 2, 10 February 2022, 150809

Abstract

Water-energy nexus (WEN) is an international hot-spot issue, while more attentions have been paid to the direct nexus effect resulting from production activities. In this context, this study firstly used the multiregional input-output (MRIO) analysis to offer a full spectrum of water and energy usage throughout the whole supply chain in China, considering production-based perspective and betweenness-based and consumption-based perspectives. And then the principal components analysis (PCA) was applied to further target the critical WEN sectors in Chinese's 30 provinces. The results show that: (1) For most of these provinces, the direct WEN pressure caused by production activities can be found in several traditional resource-intensive sectors, especially in S22 (Production and supply of electric power and steam) and S14 (Smelting and pressing of metals). (2) The most critical transmission sectors with WEN pressure was S12 (Manufacture of chemicals and chemical products), followed by S14 in most of these province. S22 was the key transmission center in several provinces, and S7 (Manufacture of textile) in Fujian and Hubei and S10 (Papermaking and printing) in Zhejiang and Hainan should also be highly-concerned. (3) For all of these provinces, the indirect WEN pressure driven by final consumption appeared in S24 (Construction industry). In addition, S16 (Manufacture of general and special-purpose machinery) and S17 (Manufacture of Transport equipment) were the other two key consumption-based WEN sectors in some provinces. Overall, the WEN pressures in Jiangsu were relatively great in China, and S12 in Hubei was the only sector facing great WEN pressure from all three perspectives. Our results can draw implications for regional sustainable development in China.

Science of The Total Environment, Volume 807, Part 2, 10 February 2022, 150856

Abstract

The rise in living standards and the continuous development in the global economy led to the depletion of resources and increased waste generation per capita. This waste might posture a significant threat to human health or the environmental matrices (water, air, soil) when inadequately treated, transported, stored, or managed/disposed of. Therefore, effective waste management in an economically viable and environmentally friendly way has become meaningful. Prominent technology is the need of the day for circular economy and sustainable development to reduce the speed of depletion in resources and produce an alternative means for the future demands in the different sectors of science and technology. In order to meet the potential requirements for energy production or producing secondary raw material, solid waste may be the prime source. The activities of living organisms convert waste products in one form or another in which electronic waste (e-waste) is a modern-day problem that is growing by leaps and bounds. The disposal protocols of the e-waste management need to be given proper attention to avoid its hazardous impacts. The e-waste is obtained from any equipment or devices that run by electricity or batteries like laptops, palmtops, computers, televisions, mobile phones, digital video discs (DVD), and many more. E-waste is one of the rapidly growing causes of world pollution today. Plenty of research is available in the scientific literature, which shows different approaches being set up and followed to manage and dispose of waste products. These strategies to manage waste products designed by the states all over the globe revolves around minimal production, authentic techniques for the management of waste produced, reuse and recycling, etc. The virtual survey of the available literature on waste management shows that it lacks specificity regarding the management of waste products parallel to ecological sustainability. The presented review covers the sources, potential environmental impacts, and highlights the importance of waste management strategies to provide the latest and updated knowledge. The review also put forward the countermeasures that need to be taken on national and International levels addressing the sensitive issue of waste management.

Science of The Total Environment, Volume 807, Part 2, 10 February 2022, 150869

Abstract

High-intensity emission controls were implemented in Nanjing and in 8 surrounding cities to ensure good air quality during the 2014 summer Youth Olympic Games (YOG). An Aerodyne soot-particle aerosol mass spectrometer (SP-AMS) was deployed at a downwind site of downtown Nanjing to investigate the chemical composition, sources, and size distribution of submicron aerosols (PM1), in response to emission control policies. However, results show that emission controls played a negligible role in reducing PM1 concentration during the YOG period, yet primary precursors such as NOx and SO2 were decreased by 10–20%. Low wind speed, high relative humidity, and high ozone (O3) concentration likely play a significant role in the production and accumulation of the oxygenated organic aerosol (OOA) and the secondary inorganic aerosols (SIA) in summer Nanjing. We propose that long-term regional emission reduction could be a solution for future air pollution mitigation strategies in downwind cities of the YRD region, and that seasonal meteorological characteristics in a specific region should be considered before emission control policies are made.

Science of The Total Environment, Volume 807, Part 2, 10 February 2022, 150886

Abstract

Atmospheric aerosols play an important role in affecting clouds and precipitation by serving as condensation/ice nuclei. However, how to quantify the contribution of anthropogenic aerosols to the alteration of clouds and precipitation remains unknown. In this study, using a Weather Research and Forecasting-Chemistry (WRF-Chem) model, we quantified the impacts of anthropogenic aerosols on cloud water properties under different precipitation grades during a single rainfall event over eastern China. The results of this study show that anthropogenic aerosols have varying effects on hourly precipitation with heavy (greater than 1.04 mm/h), moderate (0.41–1.04 mm/h), and light (less than 0.41 mm/h) grades. Due to the presence of anthropogenic aerosols, heavy precipitation is intensified by 70.96%; however, moderate and light precipitation is further weakened by 24.87% and 86.43%, respectively. For heavy precipitation, the addition of anthropogenic aerosols induces an enhancement in upward motion, increases the cloud water path and effective radius through the aerosol-radiation interaction (ARI) effect, which is the main reason for the intensification of heavy-grade precipitation. In addition, the weakened upward motion and decreased ice water path caused by ARI and aerosol-cloud interaction (ACI) effects play common roles in reducing moderate and light precipitation. Studying anthropogenic aerosols' impacts on precipitation is of great importance for understanding the influence of anthropogenic pollution on the weather and climate and even for promoting precipitation forecasting and prediction.

Science of The Total Environment, Volume 807, Part 2, 10 February 2022, 150527

Abstract

Ecological restoration programs have significantly contributed to the improvement of ecosystem services in the past two decades. However, due to climate change and rapid land use change, planning and management of ecosystem services restoration programs are still challenging, particularly how to identify and quantify the specific contribution of natural and human drivers of ecosystem services dynamics, how to assess and simulate the integrated impacts of climate-land use change interactions on changes in ecosystem services, insufficient simulation of mid- and long-term impacts of different ecological restoration programs, and lack of identification of ecological restoration thresholds. To overcome the challenges, we propose a new framework for restoring ecosystem services programs as potential solutions to the challenges. The framework includes attribution analysis of changes in ecosystem services, assessment and projections of ecosystem services dynamics under the integrated impacts of climate-land use change interactions, simulation of mid- and long-term effects of ecological programs and identification of ecological restoration threshold, which forms the logic chain of the framework, i.e. theory foundation-techniques support-application cases-policy implications. We finally recommend four related research directions and steps forward to overcome the challenges, including (1) Step 1: establish attribution analysis method of ecosystem services dynamics based on ecological thermodynamics and partial differential equation; (2) Step 2: Assess and simulate the impacts of coupled climate-land use change interactions on ecosystem services dynamics; (3) Step 3: Simulate the mid- and long-term impacts of different ecological restoration programs; and (4) Step 4: Identify ecological restoration thresholds. This study could provide insights for improving management of ecosystem services restoration programs in the context of rapid land use change and continuous climate change.

Journal of Cleaner Production, Volume 334, 1 February 2022, 130231

Abstract

This study employs spatial simultaneous equations models with the Generalized Spatial Three-Stage Least Squares (GS3SLS) method to evaluate the interrelationship between economic growth and air pollution under local government competition for China's "2 + 26” cities from 2007 to 2016. The results show an unbalanced spatial agglomeration effect of economic growth and air pollution across the region. Findings indicate that air pollution accompanies economic growth in the "2 + 26” cities, and economic growth has a U-shaped relationship with air pollution. Moreover, tax income and foreign investment competitions increase air pollution. Suggestions for the "2 + 26” cities include organizing a cross-regional agency for integrated management of the economy and air quality, constructing multiple economic-center cities, reforming the political promotion mechanism, and developing the ecological compensation mechanism for air pollution.

Journal of Cleaner Production, Volume 335, 10 February 2022, 130240

Abstract

The construction sector has suffered from low productivity and considerable wastes due to the fragmentation of its value chain, the large number of diverse stakeholders and the complex nature of the projects. A promising way to reduce construction wastes and encourage value chain integration is to implement circular economy (CE) strategies. Many recent studies in the fields of construction management and sustainability have advanced CE from multiple perspectives. There remains room to refine such knowledge by clearly identifying all the possible strategies and drivers to be carried out in practice that help stakeholders slow, narrow, and close resource loops. A systematic review was conducted in this study to examine the relevant literature on construction circularity to address the knowledge gap. A total of 61 relevant publications in the past ten years were rigorously selected and reviewed in-depth based on an iterative coding procedure. The phase-specific circular economy strategies were classified into five categories: 1) Design phase (including design with LCA, design with reused materials, design with recycled materials, and design for disassembly); 2) Manufacturing phase (including industrial symbiosis); 3) Construction phase (including lean construction methods); 4) Operation and maintenance phase (including service life planning); and 5) End-of-Life phase (including diversion of wastes). Internal drivers were identified to consist of BIM (Building Information Modelling)-based design and evaluation, IoT (Internet of Things)-based material tracking, predictive data analytics, and logistics network optimization. External drivers included material certifications and legislation, financial incentives, market maturity and material flow balance, and social engagement. The review revealed that the BIM-based and LCA-based methods have been widely used; however, logistics network optimization to allow industrial symbiosis was not adequately addressed in the existing literature. The strategies and drivers were also composed into a framework to guide the future implementation of circular construction projects. The framework could help construction researchers and project participants clearly understand circular resource flows across various construction supply chain stages and thus help them to keep up with the global action of "Net Zero Emission” by 2050.

Science of The Total Environment, Volume 806, Part 2, 1 February 2022, 150447

Abstract

Decision Support Systems (DSS) for Sustainable Urban Drainage Systems (SUDS) are a valuable aid for SUDS widespread adoption. These tools systematize the decision-making criteria and eliminate the bias inherent to expert judgment, abridging the technical aspect of SUDS for non-technical users and decision-makers. Through the collection and careful assessment of 120 papers on SUDS models and SUDS-DSS, this review shows how these tools are built, selected, and used to assist decision-makers questions. The manuscript classifies the DSS based on the question they assist in answering, the spatial scale used, the software selected, among other aspects. SUDS-DSS aspects that require more attention are identified, including environmental and social considerations, SUDS trains performance and criteria for selection, stochasticity of rainfall, and future scenarios impact. Suggestions for SUDS-DSS are finally offered to better equip decision-makers in facing emerging stormwater challenges in urban centers.

Science of The Total Environment, Volume 806, Part 3, 1 February 2022, 150728

Abstract

Sewers are important parts of wastewater treatment facilities and the fungal microbial communities therein make large contributions to the biotransformation of wastewater. Therefore, this experiment constructed an experimental sewer system and characterized the fungal microbial communities using ITS high-throughput sequencing technology in combination with network structure analysis and statistical correlation analysis methods. The results demonstrated that the overall diversity of the fungal communities gradually increased as growth phases progressed, but the dominant groups differed significantly among phases. In the early growth phase (RS1) the dominant genera were Apiotrichum and Inocybe, with abundances of 34% and 14%, respectively, while the middle and late growth phases (RS2 and RS3) were dominated by Candida, with a relative abundance of 47%–66%. CCA and correlation analysis showed that the fungal communities diversity from the artificial sewers had significant positive correlations with COD (r2 = 0.44, p < 0.05) and NH4+ (r2 = 0.64, p < 0.05) and that environmental factors significantly influenced the abundances of Fusarium and Aspergillus. Network analysis revealed differences in the fungal groups representing key nodes during different periods. Candida, Trichosporon, Fusarium, and Aspergillus played important roles in the microbial ecosystem of the simulated sewer systems. This study provides data-supported insight into the bacterial-fungal interaction mechanisms and associated pollutant biodegradation technologies in sewers.

Science of The Total Environment, Volume 806, Part 3, 1 February 2022, 150409

Abstract

This study focused on the resource recovery of sludge treatment by quantifying the environmental contributions, identifying the influential factors, and comparing different scenarios. Life cycle assessment (LCA) of sewage sludge treatment was carried out to estimate the environmental impacts of six scenarios: (1) co-digestion of sludge and food waste; (2) co-gasification of sludge and woody waste; (3) co-incineration of sludge and used oil; (4) landfilling; (5) incineration; and (6) anaerobic digestion combined with incineration. Results demonstrate that the resource recovery had a substantial contribution to the environmental performance of the sludge treatment, while the degree of contribution was largely affected by various treatment scenarios and diverse impact categories. To gain deep insight into the parameters related to resource recovery, sensitivity analysis was performed to investigate the influence of the parameters on the LCA results, including the organic content, conversion efficiency of organic matter to methane, and other energy conversion efficiencies. After integrating the inventory variation of those parameters into the decision process via the Monte Carlo simulation, results indicate that no obviously superior scenario could be identified. Conversely, when parameter uncertainty was not considered, co-gasification of sludge and woody waste exhibited the most preferable environmental performance. Overall, this study demonstrates that considering the parameter uncertainty of resource recovery will contribute to a more transparent evaluation process, but will inevitably increase the complexity of the decision-making process based on LCA results because it is difficult to determine a sludge treatment scenario that decisively outperforms the others.

Science of The Total Environment, Volume 806, Part 3, 1 February 2022, 151296

Abstract

Trees in the urban right-of-way areas have increasingly been considered part of a suite of green infrastructure practices used to manage stormwater runoff. A paired-catchment experimental design (with street tree removal as the treatment) was used to assess how street trees affect major hydrologic fluxes in a typical residential stormwater collection and conveyance network. The treatment consisted of removing 29 green ash (Fraxinus pennsylvanica) and two Norway maple (Acer platanoides) street trees from a medium-density residential area. Tree removal resulted in an estimated 198 m3 increase in surface runoff volume compared to the control catchment over the course of the study. This increase accounted for 4% of the total measured runoff after trees were removed. Despite significant changes to runoff volume (p ≤ 0.10), peak discharge was generally not affected by tree removal. On a per-tree basis, 66 L of rainfall per m2 of canopy was lost that would have otherwise been intercepted and stored. Runoff volume reduction benefit was estimated at 6376 L per tree. These values experimentally document per-capita retention services rendered by trees over a growing season with 42 storm events. These values are within the range reported by previous studies, which largely relied on simulation. This study provides catchment scale evidence that reducing stormwater runoff is one of many ecosystem services provided by street trees. This study quantifies these services, based on site conditions and a mix of deciduous species, and serves to improve our ability to account for this important yet otherwise poorly constrained hydrologic service. Engineers, city planners, urban foresters, and others involved with the management of urban stormwater can use this information to better understand tradeoffs involved in using green infrastructure to reduce urban runoff burden.

Science of The Total Environment, Volume 806, Part 3, 1 February 2022, 151276

Abstract

Anthropogenic lead (Pb) in soils poses risks to human health, particularly to the neuropsychological development of exposed children. Delineating the sources and potential bioavailability of soil Pb, as well as its relationship with other contaminants is critical in mitigating potential human exposure. Here, we present an integrative geochemical analysis of total elemental concentrations, radionuclides of 137Cs and 210Pb, Pb isotopic compositions, and in vitro bioaccessibility of Pb in surface soils sampled from different locations near Durham, North Carolina. Elevated Pb (>400 mg/kg) was commonly observed in soils from urban areas (i.e., near residential house foundation and along urban streets), which co-occurred with other potentially toxic metal(loids) such as Zn, Cd, and Sb. In contrast, soils from city parks and suburban areas had systematically lower concentrations of metal(loids) that were comparable to geological background. The activities of 137Cs and excess 210Pb, coupled with their correlations with Pb and co-occurring metal(loids) were used to indicate the persistence and remobilization of historical atmospherically deposited contaminants. Coupled with total Pb concentrations, the soil Pb isotopic compositions further indicated that house foundation soils had significant input of legacy lead-based paint (mean = 1.1895 and 2.0618 for 206Pb/207Pb and 208Pb/206Pb, respectively), whereas urban streetside soils exhibited a clear mixed origin, dominantly of legacy leaded gasoline (1.2034 and 2.0416) and atmospheric deposition (1.2004–1.2055 and 2.0484–2.0525). The in vitro bioaccessibility of Pb in contaminated urban soils furthermore revealed that more than half of Pb in the contaminated soils was potentially bioavailable, whose Pb isotope ratios were identical to that of bulk soils, demonstrating the utility of using Pb isotopes for tracking human exposure to anthropogenic Pb in soils and house dust. Overall, this study demonstrated a holistic assessment for comprehensively understanding anthropogenic Pb in urban soils, including its co-occurrence with other toxic contaminants, dominant sources, and potential bioavailability upon human exposure.

Science of The Total Environment, Volume 806, Part 3, 1 February 2022, 151273

Abstract

Background

During 2014 to 2019, the SaniPath Exposure Assessment Tool, a standardized set of methods to evaluate risk of exposure to fecal contamination in the urban environment through multiple exposure pathways, was deployed in 45 neighborhoods in ten cities, including Accra and Kumasi, Ghana; Vellore, India; Maputo, Mozambique; Siem Reap, Cambodia; Atlanta, United States; Dhaka, Bangladesh; Lusaka, Zambia; Kampala, Uganda; Dakar, Senegal.

Objective

Assess and compare risk of exposure to fecal contamination via multiple pathways in ten cities.

Methods

In total, 4053 environmental samples, 4586 household surveys, 128 community surveys, and 124 school surveys were collected. E. coli concentrations were measured in environmental samples as an indicator of fecal contamination magnitude. Bayesian methods were used to estimate the distributions of fecal contamination concentration and contact frequency. Exposure to fecal contamination was estimated by the Monte Carlo method. The contamination levels of ten environmental compartments, frequency of contact with those compartments for adults and children, and estimated exposure to fecal contamination through any of the surveyed environmental pathways were compared across cities and neighborhoods.

Results

Distribution of fecal contamination in the environment and human contact behavior varied by city. Universally, food pathways were the most common dominant route of exposure to fecal contamination across cities in low-income and lower-middle-income countries. Risks of fecal exposure via water pathways, such as open drains, flood water, and municipal drinking water, were site-specific and often limited to smaller geographic areas (i.e., neighborhoods) instead of larger areas (i.e., cities).

Conclusions

Knowledge of the relative contribution to fecal exposure from multiple pathways, and the environmental contamination level and frequency of contact for those "dominant pathways” could provide guidance for Water, Sanitation, and Hygiene (WASH) programming and investments and enable local governments and municipalities to improve intervention strategies to reduce the risk of exposure to fecal contamination.

Science of The Total Environment, Volume 806, Part 3, 1 February 2022, 151268

Abstract

PAHs (polycyclic aromatic hydrocarbons) in urban areas are usually bound to particles. Concentrations are different in different compartments (airborne particles, street dust, suspended sediments in rivers and channels). This study follows concentrations of PAHs from particles in air to street dust and finally suspended sediments in the city of Tehran, Iran compared to Tübingen, Germany. Data sets are based on own investigations (PAHs on suspended sediments), or taken from literature studies (PAHs in street dust and airborne particles). Based on a cross-comparison of concentrations of PAHs on particles, and their congener distribution patterns, the occurrence, interrelation (exchange and mixing processes), as well as possible dilution processes among PAHs in the different particle classes are disentangled. Results show that for Tehran and Tübingen PAHs in airborne particles are very high (in the range of 500 mg kg−1). However, in street dust and suspended sediments PAHs concentrations on particles are around 100 times lower. Surprisingly concentrations in street dust and suspended sediments are 5 to 10 times lower in Tehran (average 0.5 mg kg−1) than in Tübingen (average 5 mg kg−1). Since it is unlikely that PAHs emissions are lower in the Tehran megacity, an effective dilution of the atmospheric signal by uncontaminated (background) particles is hypothesized. Uncontaminated particles may stem from wind erosion of bare surfaces, construction and sand mining sites or even dust from the desert areas, which are frequent in arid climate in Tehran.

Science of The Total Environment, Volume 806, Part 3, 1 February 2022, 151212

Abstract

Applying an electric field in the membrane filtration was an effective method to alleviate membrane fouling and enhance the trace organic compounds (TrOCs) removal. The secondary effluent of a municipal wastewater treatment plant was used as feed water to evaluate the performance of the electric field coupled microfiltration system. Applying a 1.25 V voltage reduced 22.9% membrane fouling by electrophoretic force, and the membrane fouling was alleviated by 70.8% at 3 V by electrochemical oxidation and electric field force. At 3 V, active chlorine and hydroperoxide generated on the electrodes and the acidic environment formed around the anode significantly inhibited the growth of microorganisms and their attachment on the membrane surface, and thus reduced the membrane fouling formed by microorganisms. Electrochemical oxidation also removed the protein in wastewater and changed the main organic components of membrane fouling from microorganisms, protein, and polysaccharide to humic substances and polysaccharide. Furthermore, the electrophoretic force and acidic environment reduced the electrostatic repulsion of humic substances and made them tend to aggregate and form hydrophilic porous fouling structures, which obviously lowered filtration resistance and showed significant membrane fouling mitigation. Also, the electric field effectively enhanced the removal of target TrOCs through electrochemical oxidation and electric field force improving the elimination of TrOCs from 8.5% ~ 26.1% at 0 V to 35.9% ~ 84.8% at 3 V.

Science of The Total Environment, Volume 806, Part 3, 1 February 2022, 151202

Abstract

Total, regional and local deposition fractions of urban-type aerosol particles with diameters of 50, 75, 110 and 145 nm were modelled and studied in their dry state and after their hygroscopic growth using a Stochastic Lung Model and a Computational Fluid and Particle Dynamics method. Healthy subjects and patients with severe chronic obstructive pulmonary disease (COPD) were considered. The hygroscopic growth factors (HGFs) adopted were determined experimentally and represent a real urban-type environment. The hygroscopic growth of particles resulted in decrease of the deposition fractions in all major parts of the healthy respiratory system and the extent of the deposited fractions was rising monotonically with particle size. In the extrathoracic (ET) region, the relative decrease was between 7% and 13%. In the lungs the deposition decreased by 11–16%. The decrease of deposition fraction due to hygroscopic growth was more accentuated in the conductive airways (up to 25%) and less pronounced towards the terminal airways. The spatial distribution of the deposited particles remained highly inhomogeneous with some areas containing thousands times more particles than the average number of particles per unit surface area. For COPD patients, the hygroscopic growth produced similar deposition alterations in the ET region than for healthy subjects. In the conductive airways, however, the particle growth caused a substantial relative decrease in the deposition fractions. In contrast, the relative depositions of hygroscopic particles increased in the acinar region.

Science of The Total Environment, Volume 806, Part 4, 1 February 2022, 151484

Abstract

Planetary boundaries define the safe operating space of human beings relative to the Earth's system, which is of great significance in helping human beings predict environmental safety limits. However, ecological boundaries have not been presented or downscaled to regional levels. Moreover, a method has not been developed to quantitatively measure the gap between the value of the services provided by the ecosystem and the size of the urban population and economy that the ecosystem can carry. Herein, we propose the concept and calculation model of the "ecological boundary” to quantitatively assess the ecosystem security gap size transgressed by humans. Ecological boundaries are defined as the maximum population and economic scale that a certain area can support under a certain ecologically productive area. The purpose of this paper is to investigate the ecological boundary in megacities, and Beijing is considered as a specific case. The results show that the consumption of natural resources has transgressed its ecological boundary in Beijing. The direct consequence is that the ecological well-being per capita continues to decrease. Fortunately, with decreases in the ecological footprint and land use/land cover change dynamic degree, the ecological boundary gap is gradually tightening. Moreover, the role of ecological boundaries as early warning signals of undesirable urban ecological environmental changes is discussed, the significance of the monetization of ecological boundaries is described, the factors underlying the ecological boundary gap in the process of accelerating urbanization in China are analyzed, and policy recommendations for resolving the threat to ecological security boundaries by megacities are presented. The primary purpose of our study is provide policymakers with information on the gap between the current well-being of humankind and critical capacity thresholds, which can help determine whether human activities have fallen into an unsustainable state that may result in undesirable eco-environmental changes that could have detrimental or even disastrous consequences for the population of a region.

Science of The Total Environment, Volume 806, Part 4, 1 February 2022, 151459

Abstract

Fine particulate matter (PM2.5) and its constituents pose great threatens to public health. The spatial-temporal characteristics of some key chemical constituents, such as sulfate, nitrate, and especially toxic trace elements in China has remained unclear, limiting further studies on evaluating the associated public health. Here, we conduct a two-yearlong (2012 and 2015) air quality simulation by coupling localized emission inventory for primary air pollutants and trace elements with a modified CMAQ model in a domain of China and five urban agglomerations. Associated health burdens of PM2.5 and various toxic trace elements are assessed applying exposure assessment models. The model successfully reproduces air pollution situations. Significant spatial-temporal variations of PM2.5 and chemical constituents are observed, with higher concentrations mainly occurred in North China Plain (NCP), Fenwei Plain (FWP) and Sichuan-Chongqing Basin (SCB). All chemical constituents in PM2.5 show higher concentrations in winter except for sulfate. From 2012 to 2015, the annual averaged PM2.5 concentration and its constituents decreased by 3% –20% nationally and regionally. Smaller reductions of nitrate make PM2.5 pollution become nitrate-dominated, especially in winter. Approximately 0.28 million deaths related to PM2.5 in China are avoided, while the population affected by the cancer risks of Cr (VI) and arsenic has slightly increased from 2012 to 2015. Our findings could provide critical insights on the mitigation of air pollution, as well as benefit for epidemiological studies on air pollutants related health effects.

Science of The Total Environment, Volume 806, Part 4, 1 February 2022, 151398

Abstract

The conversion of natural streams to urbanized systems with the intention of supplying the cities' water demand causes species loss across many trophic groups, with negative consequences for ecosystem functioning. High levels of watershed urbanization cause environmental changes through water quality deterioration and loss of habitat heterogeneity. However, it remains unclear how environmental changes resulting from urbanization affect the diversity of multiple trophic groups and ecosystem functions, such as biomass stock in streams. Here, using a dataset from Neotropical streams, we investigate the cascading effects of urbanization (via impoverishment of water quality and habitat heterogeneity) on richness of multiple trophic groups of fish, and their consequences to biomass stock of streams. The increase in urbanization decreased the richness and standing biomass of carnivores, omnivores, and detritivores across streams. Urbanization also decreased habitat heterogeneity and water quality, which driver a huge cascading decrease in the richness of carnivores, omnivores, and detritivores, and ultimately reduced the whole-community standing biomass. Our analysis revealed that urbanization expansion induces a cascading reduction of multitrophic diversity and standing biomass in Neotropical streams. Therefore, the predicted increase in urbanization in the coming decades should impacts the richness of multiple trophic levels, with potential negative consequences to ecosystem functioning of streams.

Science of The Total Environment, Volume 806, Part 4, 1 February 2022, 150768

Abstract

In this study, copper oxide (CuO) catalyzed peroxydisulfate (PDS) system was investigated for the inactivation of a broad range of pathogenic microorganisms from urban wastewater. Complete inactivation of Escherichia coli, Enterococcus, F-specific RNA bacteriophages from secondary treated wastewater was achieved after a short time (15–30 min) treatment with CuO (10 g/L)/PDS (1 mM) system, but spores of sulfite-reducing bacteria took 120 min. No bacterial regrowth occurred during storage after treatment. Significant reduction of the pathogens was explained by the generation of the highly selective Cu(III) oxidant, as the predominant reactive species, which could quickly oxidize guanine through a one-electron oxidation pathway. Additionally, the potential of the CuO (10 g/L)/PDS (1 mM) system to inactivate antibiotic-resistant bacteria and antibiotic resistance genes (ARB&Gs) was explored. Sulfamethoxazole-resistant E. coli was used as the model ARB and a 3.2 log of reduction was observed after 10 min of treatment. A considerable reduction (0.7–2.3 log) of selected ARGs including blaTEM, qnrS, emrB, sul1, and genes related to the dissemination of antibiotic resistance, including the Class 1 integron-integrase (intI1), and the insertion sequence (IS613) was achieved after 60 min treatment. All these findings indicated the promising applicability of the CuO/PDS system as a disinfection technology for wastewater reuse in agriculture.

Science of The Total Environment, Volume 806, Part 4, 1 February 2022, 150816

Abstract

Wastewater-based viral surveillance was proposed as a promising approach to monitor the circulation of SARS-CoV-2 in the general population. The aim of this study was to develop an analytical method to detect SARS-CoV-2 RNA in urban wastewater, and apply it to follow the trends of epidemic in the framework of a surveillance network in the Lombardy region (Northern Italy). This area was the first hotspot of COVID-19 in Europe and was severely affected. Composite 24 h samples were collected weekly in eight cities from end-March to mid-June 2020 (first peak of the pandemic). The method developed and optimized, involved virus concentration using PEG centrifugation, and one-step real-time RT-PCR for analysis. SARS-CoV-2 RNA was identified in 65 (61%) out of 107 samples, and the viral concentrations (up to 2.1 E + 05 copies/L) were highest in March-April. By mid-June, wastewater samples tested negative in all the cities corresponding to the very low number of cases recorded in the same period. Viral loads were calculated considering the wastewater daily flow rate and the population served by each wastewater treatment plant, and were used for inter- city comparison. The highest viral loads were found in Brembate, Ranica and Lodi corresponding to the hotspots of the first peak of pandemic. The pattern of decrease of SARS-CoV-2 in wastewater was closely comparable to the decline of active COVID-19 cases in the population, reflecting the effect of lock-down. This study tested wastewater surveillance of SARS-CoV-2 to follow the pandemic trends in one of most affected areas worldwide, demonstrating that it can integrate ongoing virological surveillance of COVID-19, providing information from both symptomatic and asymptomatic individuals, and monitoring the effect of health interventions.

Science of The Total Environment, Volume 806, Part 4, 1 February 2022, 151414

Abstract

Wastewater treatment plants, the last barrier between ever-increasing human activities and the environment, produce huge amounts, of unwanted semi-solid by-product - waste activated sludge. Anaerobic digestion can be used to reduce the amount of sludge. However, the process needs extensive modernisation and refinement to realize its full potential. This can be achieved by using efficient pre-treatment processes that result in high sludge disintegration and solubilization. To this end, we investigated the efficiency of a novel pinned disc rotational generator of hydrodynamic cavitation. The results of physical and chemical evaluation showed a reduction in mean particle size up to 88%, an increase in specific surface area up to 300% and an increase in soluble COD, NH4-N, NO3-N, PO4-P up to 155.8, 126.3, 250 and 29.7%, respectively. Microscopic images confirmed flocs disruption and damage to yeast cells and Epistilys species due to mechanical effects of cavitation such as microjets and shear forces. The observed cell ruptures and cracks were sufficient for the release of small soluble biologically relevant dissolved organic molecules into the bulk liquid, but not for the release of microbial DNA. Cavitation treatment also decreased total Pb concentrations by 70%, which was attributed to the reactions triggered by the chemical effects of cavitation. Additionally, the study confirmed the presence of microplastic particles and fibers of polyethylene, polyethylene terephthalate, polypropylene, and nylon 6 in the waste activated sludge.

Chemosphere, Volume 288, Part 2, February 2022, 132588

Abstract

The increasing industrialization and urbanization are also triggering environmental pollution, mostly unnoticed, in the case of soil pollution due to uncontrolled contamination by toxic elemental dispersion. The present study focused on this aspect and studied the clean-up of urban soil in a low-cost and eco-friendly way to restrict arsenic (As), lead (Pb) and mercury (Hg) contamination. Four potential ornamental plants, Catharanthus roseus (vinca), Cosmos bipinnatus (cosmos), Gomphrena globose (globosa) and Impatiens balsamina (balsamina) were used along with zero valent iron (ZVI) nanoparticles (Fe NPs) for remediation of the soil spiked with As (70 mg kg−1), Pb (600 mg kg−1) and Hg (15 mg kg−1) in a 60 d pot experiment. All plants were divided into four groups viz. control, spiked, spiked+20 mg kg−1 ZVI NP and spiked+50 mg kg−1 ZVI NP. FTIR and SEM were used for ZVI NP characterization. Soil and plant analyses and elemental assessments were done using ICP-MS, XRF and SEM. Among the four plants, cosmos showed the maximum accumulation of toxic elements (41.24 ± 0.022 mg kg−1 As, 139.15 ± 11.2 mg kg−1 Pb and 15.57 ± 0.27 mg kg−1 Hg) at 60 d. The application of ZVI NP at 20 mg kg−1 dosage was found to further augment plants’ potential for metal(loid)s accumulation without negatively hampering their growth. Cosmos were observed to reduce soil As from 81.35 ± 1.34 mg kg−1 to 28.16 ± 1.38 mg kg−1 (65.38%), Pb from 1132.47 ± 4.66 to 516.09 ± 3.15 mg kg−1 (54.42%) and Hg from 17.35 ± 0.88 to 6.65 ± 0.4 mg kg−1 (61.67%) at 60 d in spiked + 20 mg kg−1 ZVI NP treatment. Balsamina was the most sensitive plant and showed the least metal(loid)s accumulation. In conclusion, three of these plants are potent enough to use together for a better and enhanced removal of toxic elements from the contaminated soil with cosmos to be the best amongst these in urban areas.

Science of The Total Environment, Volume 807, Part 1, 10 February 2022, 150758

Abstract

In this work, a pilot biobed was built up to treat pesticide-contaminated wastewaters discharged from a formulation plant. The pre-treated wastewater was spiked with additional pesticides in order to simulate a scenario of higher contamination: glyphosate, atrazine, imidacloprid, prometryn and carbendazim were added to reach a final Total Organic Carbon (TOC) concentration of 70 mg L−1. An Intermediate Bulk Container (IBC) was filled with a biomixture of soil and foxtail millet stubble (50:50% v v−1), and 200 l of the wastewater was added to the system recycling tank. The recirculation to the IBC was established for 12 h. After that (Day 0), the recirculation was turned on during the assay only to maintain the moisture for 180 days. Biomixture and wastewater samples were taken periodically to analyse pesticides and phytotoxicity in both matrices. In addition, hydrolytic and phenoloxidase activities, total bacteria and yeast and fungi communities were determined in the biomixture.

The designed pilot scale biobed allowed to treat wastewaters with high concentration of pesticides reaching a complete removal of glyphosate, AMPA, atrazine, carbendazim and prometryn at 180 days. A good degradation percentage of the recalcitrant imidacloprid was achieved (60%) and the biomixture showed enough biological activity to continue treating additional wastewater. The root elongation index from the germination test showed low toxicity on day 180 both in biomixture and wastewater.

The millet stubble resulted an appropriate lignocellulosic material to be used in biobeds to treat a wide variety of pesticides. The application of the seed germination test proved to be a low cost and simple tool to determine the end point of the process.

Science of The Total Environment, Volume 807, Part 2, 10 February 2022, 150820

Abstract

Global concern about environmental pollution has increased in recent times due to the cumulative harmful impact on the human health occasioned by the diverse toxic substances released into the environment. Water reduced availability for human consumption and its pollution have been paid so much attention due to their relevance in agricultural and industrial activities. In this context, the advanced oxidation processes for removing contaminants from water, more specifically photocatalytic processes, have displayed their usefulness due to features such as easy application, low-cost, harmless effects and sustainable decontamination efficiency. This timely review is centered on worldwide studies, where efforts aimed at employing recycled materials as supports for purification applications such as the removal of different contaminants (dyes, pharmaceutical contaminants, and heavy metals) dissolved in aqueous environments have been reported. Materials like polyethylene terephthalic (PET), polystyrene (PS), disposal textile fabrics, newspapers, aluminum soda cans, rubber, waste electronic and electric components and used batteries have been employed either as supports for immobilizing catalysts or as photocatalysts. The present work offers a discussion of the ways through which photocatalytic composites have been immobilized or produced, employed characterization techniques, removal efficiencies achieved during photocatalytic degradation and possible degradation mechanism of pollutants; not only the highlights of all these studies are discussed, but also paths for future research works that could help improve the reported results are suggested. These new practical tools stand as novel sustainable strategies for the removal of emerging contaminants reusing waste flexible materials.

Science of The Total Environment, Volume 808, 20 February 2022, 152118

Abstract

Because the disposal of phosphogypsum (PG) can lead to serious contamination of the air, soil, and water, recycling of PG has attracted wide attention. This study investigated the effect and solidification of phosphorus in the production of calcium sulfoaluminate (CSA) cement using PG as the sole CaO source. The effects of three phosphorus impurities (Ca3(PO4)2, CaHPO4, Ca(H2PO4)2) on the decomposition of CaSO4, formation of minerals, microstructure of the clinker, and the hydration and mechanical properties of the cement were studied. Experimental results show that Ca3(PO4)2 and Ca(H2PO4)2 promoted the decomposition of CaSO4 and the formation of clinker minerals with the increase in P2O5 content, whereas CaHPO4 showed a promoting effect only when the P2O5 content was more than 1.5 wt%. The increase in phosphorus incorporation in Ca2SiO4 leads to the transformation of β-Ca2SiO4 to α′-Ca2SiO4 and then to Ca7Si2P2O16. The presence of three phosphates in the clinker enhanced the growth of crystal grains and the generation of a liquid phase. Compared with Ca4Al6SO16 without phosphorus, the hydration reaction of phosphorus-bearing Ca4Al6SO16 started later and ended earlier, and the reaction time was shorter. The presence of phosphorus impurities reduces the 1-day strength of CSA cement but does not affect the development of the 3-day and 28-day strengths. Considering environmental aspects, the solidification of phosphorus in the production of CSA clinker were quantified by measuring the distribution of elements. The results indicated that phosphorus is solidified by Ca4Al6SO16, Ca2SiO4, and Ca4Al2Fe2O10, and Ca2SiO4 has a stronger ability to solidify phosphorus than the other two minerals. Ca3(PO4)2 is more difficult to solidify than CaHPO4 and Ca(H2PO4)2. This study is of great significant to guide the large-scale clean utilization of PG in the production of CSA cement.

Science of The Total Environment, Volume 808, 20 February 2022, 152071

Abstract

It is proposed that microplastics discharged from wastewater treatment plants act as a vector of pharmaceuticals. In this study, adsorption of pharmaceuticals to polyethylene microplastics was investigated in municipal wastewater. Pharmaceuticals for study were selected to represent different speciation (anionic, cationic, and neutral) and a range of pH dependant octanol-water distribution coefficients (log DOW). Findings revealed adsorption favoured those in cationic form with the greatest hydrophobicity (e.g., fluoxetine log DOW 2.0 at pH 7.8). Adsorption of anionic pharmaceuticals was restricted due to repulsion with the microplastic's negatively charged surface. Only atorvastatin had any appreciable adsorption due to its comparatively high log DOW value (2.9). Those pharmaceuticals predominantly in neutral form (carbamazepine and ketamine) with log DOW values ≥2.4 had similar adsorption. Freundlich KF values were 3400, 386, 284, 259 and 218 (mg kg−1)(mg L−1)1/n for fluoxetine, propranolol, atorvastatin, ketamine, and carbamazepine, respectively. All pharmaceuticals with log DOW values <1.0 (atenolol, gliclazide, bezafibrate, and ifosfamide) did not adsorb to microplastics, irrespective of their speciation. Changing composition of wastewater (pH, dilution with stormwater and NaCl addition) within the range expected for municipal wastewater had limited influence on adsorption. Pharmaceutical desorption from microplastics was assessed in river water and simulated gastric and intestinal fluids. Solution pH was considered the most important factor for pharmaceutical desorption, influencing both pharmaceutical speciation and microplastic surface charge. Greatest desorption was observed for the cationic pharmaceuticals in gastric fluids due to a reduced surface charge of the microplastics under low pH conditions. Up to 50% desorption of fluoxetine occurred in gastric fluid at 37 °C. These findings show that pharmaceuticals adsorbed to microplastics are ‘bioavailable’. However, this is often overlooked as an exposure route to aquatic organisms because water samples are normally pre-filtered prior to chemical analysis.

Science of The Total Environment, Volume 808, 20 February 2022, 152123

Abstract

To tackle membrane fouling and limited removals of pollutants (nutrients and emerging pollutants) that hinder the wide applications of membrane bioreactor (MBR), attached growth MBR (AGMBR) combining MBR and attached growth process has been developed. This review comprehensively presents the up-to-date developments of media used in both aerobic and anaerobic AGMBRs for treating wastewaters containing conventional and emerging pollutants. It also elaborates the properties of different media, characteristics of attached biomass, and their contributions to AGMBR performance. Conventional media, such as biological activated carbon and polymeric carriers, induce formation of aerobic, anoxic and/or anaerobic microenvironment, increase specific surface area or porous space for biomass retention, improve microbial activities, and enrich diverse microorganisms, thereby enhancing pollutants removal. Meanwhile, new media (i.e. biochar, bioaugmented carriers with selected strain/mixed cultures) do not only eliminate conventional pollutants (i.e. high concentration of nitrogen, etc.), but also effectively remove emerging pollutants (i.e. micropollutants, nonylphenol, adsorbable organic halogens, etc.) by forming thick and dense biofilm, creating anoxic/anaerobic microenvironments inside the media, enriching special functional microorganisms and increasing activity of microorganisms. Additionally, media can improve sludge characteristics (i.e. less extracellular polymeric substances and soluble microbial products, larger floc size, better sludge settleability, etc.), alleviating membrane fouling. Future studies need to focus on the development and applications of more new functional media in removing wider spectrum of emerging pollutants and enhancing biogas generation, as well as scale-up of lab-scale AGMBRs to pilot or full-scale AGMBRs.

Science of The Total Environment, Volume 808, 20 February 2022, 152111

Abstract

Chemically reactive mine tailings are a potential resource for drawing down carbon dioxide out of the atmosphere in mineral weathering schemes. Such carbon dioxide removal (CDR) systems, applied on a large scale, could help to meet internationally agreed targets for minimising climate change, but crucially we need to identify what materials could react fast enough to provide CDR at relevant climate change mitigation timescales. This study focuses on a range of silicate-dominated tailings, calculating their CDR potential from their chemical composition (specific capacity), estimated global production rates, and the speed of weathering under different reaction conditions. Tailings containing high abundances of olivine, serpentine and diopside show the highest CDR potential due to their favourable kinetics. We conclude that the most suitable tailings for CDR purposes are those associated with olivine dunites, diamond kimberlites, asbestos and talc serpentinites, Ni sulphides, and PGM layered mafic intrusions. We estimate the average annual global CDR potential of tailings weathered over the 70-year period 2030–2100 to be ~93 (unimproved conditions) to 465 (improved conditions) Mt/year.

Results indicate that at least 30 countries possess tailings materials that, under improved conditions, may offer a route for CDR which is not currently utilised within the mining industry. By 2100, the total cumulative CDR could reach some 33 GtCO2, of which more than 60% is contributed by PGM tailings produced in Southern Africa, Russia, and North America. The global CDR potential could be increased by utilization of historic tailings and implementing measures to further enhance chemical reaction rates. If practical considerations can be addressed and enhanced weathering rates can be achieved, then CDR from suitable tailings could contribute significantly to national offset goals and global targets. More research is needed to establish the potential and practicality of this technology, including measurements of the mineral weathering kinetics under various conditions.

Science of The Total Environment, Volume 809, 25 February 2022, 151134

Abstract

To effectively reduce the compound pollution of fine particulate matter (PM2.5) and ozone (O3), volatile organic compound (VOC) emission sources are being extensively studied. Studies on VOC emission characteristics have mainly focused on solvent-using and technological sources, while research on the combustion processes of high-energy-consuming industries remains limited. Here, we investigate the emission characteristics of 102 VOC species emitted from eight sources (sintering, pelletizing, steel smelting, a coke oven chimney, the topside of a coke oven, thermal power, and two types of cement kilns) used in four types of high-energy-consuming industries. Our results show significant differences among these sources. The average VOC mass concentrations varied from 0.14 to 7.08 mg/m3. Alkanes had the highest percentage contribution to VOCs from sintering (45.9%) and thermal power (44.6%), while aromatics had the highest percentage contribution from steel smelting (47.8%) and the topside of the coke oven (52.9%). Alkenes were abundant in the coke oven chimney (49.1%), and oxygenated VOCs accounted for 65.3% of the total VOCs from pelletizing. We also observed notable differences between the two types of cement kilns. In general, ethane, ethene, benzene, propane, acetaldehyde, and chloromethane were the dominant VOC species in all sources. The differences between the sources were due to factors such as the applied raw materials, calcination temperature, and end-of-pipe treatment. By reviewing studies from the past 20 years, we found that differences in the number of VOC species and the implementation of ultra-low emissions affect VOC emission characteristics. The coke oven chimney and cement kiln chimney-1 had the highest ozone formation potential and secondary organic aerosol potential, respectively. The VOC emissions from coking, iron and steel, thermal power, and cement industries were 1162.1, 289.9, 311.0, and 470.2 Gg, respectively. Our results highlight the need for more effective control measures to minimize VOC emissions from high-energy-consuming industries.

Science of The Total Environment, Volume 809, 25 February 2022, 151120

Abstract

Biochar has been widely studied as an adsorbent for the removal of contaminants from wastewater due to its unique characteristics, such as having a large surface area, well-distributed pores and high abundance of surface functional groups. Critical review of the literature was performed to understand the state of research in utilizing biochars for industrial wastewater remediation with emphasis on pollutants that co-exist in wastewater from several industrial activities, such as textile, pharmaceutical and mining industries. Such pollutants include organic (such as synthetic dyes, phenolic compounds) and inorganic contaminants (such as cadmium, lead). Multiple correspondence analyses suggest that through batch equilibrium, columns or constructed wetlands, researchers have used mechanistic modelling of isotherms, kinetics, and thermodynamics to evaluate contaminant removal in either synthetic or real industrial wastewaters. The removal of organic and inorganic contaminants in wastewater by biochar follows several mechanisms: precipitation, surface complexation, ion exchange, cation-π interaction, and electrostatic attraction. Biochar production and modifications promote good adsorption capacity for those pollutants because biochar properties stemming from production were linked to specific adsorption mechanisms, such as hydrophobic and electrostatic interactions. For instance, adsorption capacity of malachite green ranged from 30.2 to 4066.9 mg g−1 depending on feedstock type, pyrolysis temperature, and chemical modifications. Pyrolyzing biomass at above 500 °C might improve biochar quality to target co-existing pollutants. Treating biochars with acids can also improve pollutant removal, except that the contribution of precipitation is reduced for potentially toxic elements. Studies on artificial intelligence and machine learning are still in their infancy in wastewater remediation with biochars. Meanwhile, a framework for integrating artificial intelligence and machine learning into biochar wastewater remediation systems is proposed. The reutilization and disposal of spent biochar and the contaminant release from spent biochar are important areas that need to be further studied.

Chemosphere, Volume 288, Part 2, February 2022, 132355

Abstract

EC process, which stands for Electrocoagulation, is considered a widespread wastewater remediation method that is investigated widely for an extensive variety of wastewater resources, based on its flexibility, easy setup, eco-friendly nature, and low footprint. The critical operative factors in the EC process and the crucial relation between EC and the typical chemical coagulation approach had been thoroughly evaluated because they are the main variables that govern the process of contaminant elimination. As a result, the EC process requires further investigations for scale-up simulations in the manufacturing scopes and optimization of operational parameters. Furthermore, the current paper studies the novel integrated separation methods with the combined EC process and also their limitations for improved wastewater remediation process for cleaner wastes, recycling processes, and water recovery. In this paper, the EC enhancement processes toward oil removal from wastewater have been reviewed which includes a concise representation of the source and features of oily wastewater. Additionally, the advanced remediation methods for oil-contained wastewater and the electrocoagulation process are presented. This review summarized the present utilization of electrocoagulation to eliminate oil from wastewater. Besides the process optimization and modeling investigations, the parameters that significantly affect the electrocoagulation remediation effectiveness are evaluated. Finally, the cutting-edge and sophisticated methods of electrocoagulation process for oil removal are presented.

Chemosphere, Volume 288, Part 2, February 2022, 132481

Abstract

Soil structure was damaged from solvents and localised heating after a large fire which had potential to limit bioremediation of an industrial site. Laboratory prototypes (biopile, bioflushing, bioreactor, slurry reactor) for treating the site contamination were developed. After successful laboratory testing (96% removal of main contaminant, phenol), the bioflushing prototype was then applied in the field. Field prototype removed 95% phenol using a small scale 2000 L bioreactor. Field trial was then scaled to commercial clean-up. Intensive soil grid sampling after 600 days treatment revealed hotspots of solvents remaining as well as the heterogeneity in the subsurface, however overall concentrations were substantially decreased below the initial assessment. The process decreased initial soil phenol concentrations of approximately 500 mg/kg (pre-treatment area average) to 75 mg/kg across the most contaminated areas. Phenol toxicity increased with depth and is linked to increasing oxygen deficit. The study demonstrated the prototyping process enabling site clean-up and scaling for bioremediation at the industrial site, provided certainty for site owner on treatment elements and achieving improved environmental and commercial outcomes.

Chemosphere, Volume 288, Part 2, February 2022, 132483

Abstract

Globally, 80% of wastewater, among which 28% came from industry, returned to the ecosystem without treatment or reuse. The discharge of industrial wastewater poses public health and environmental concerns. The necessity and urgency of industrial wastewater treatment (IWT) will bring great challenges to most countries. This paper conducted the patent analysis combined with text mining to quantitatively analyze 11,840 patents related to IWT in the Derwent Innovations Index database. The results showed that: From 1973 to 2020, the number of patents related to IWT annually was increasing consistently. China ranked first in the number of patent publications. In contrast, the United States and some patent organizations, such as World Intellectual Property Organization, produced fewer patents, while they played more important roles in knowledge transfer. The core technology analysis suggested that method, device, material and related industry were hot topics. From activated sludge treatment technology, industrial wastewater treatment technology had gone through a development process from single technology treatment to combined technologies treatment. In the foreseeable future, research on devices for physical treatment, advanced oxidation processes, automated and energy-saving treatment systems were the promising directions.

Chemosphere, Volume 288, Part 2, February 2022, 132448

Abstract

In this world, water is considered as the Elixir for all living creatures. Human life rolls with water, and every activity depends upon water. Worldwide water resources are being contaminated due to the elevation in the population count, industrialization and urbanization. Ejection of chemicals by industries and domestic sewages remains the major reason in the destruction of natural water resources. Contaminated water with harmful microbes, chemical dyes, pesticides, and carcinogens are the root cause of many diseases and deaths of living species. In this scenario, researchers engaged in producing ultra components to remove the contaminants. Metal organic frameworks (MOF) are the desired combination of organic and inorganic materials to achieve the required target. MOFs possess unique characteristics like tunable internal structure, porosity, crystallinity and high surface area which enable them for energy and environmental application. For the past years, MOFs are concentrated more as a photocatalyst in the treatment of polluted water. These research studies discuss the improvement of photocatalytic performance of MOF by the incorporation of metals, metal coupled with nanoparticles like polymers, graphene, etc., into it to achieve the enhanced photocatalytic activity by scavenging entire chemicals and harmful microbes to retain the quality of water. The target of this review article is to focus on the state of the art research work on MOFs in photocatalytic water treatment technique.

Chemosphere, Volume 288, Part 2, February 2022, 132525

Abstract

Herein, a simple but highly effective strategy of thermal annealing to modulate oxygen vacancies related defects in ZnFe2O4 (ZFO) nanoparticles for obtaining enhanced wastewater treatment efficiencies is reported. The as-prepared nanoparticles were thermally annealed at three different temperatures (500 °C, 600 °C and 700 °C) and their phase purity was confirmed by X-ray diffraction (XRD). All samples were found to exhibit pure phases of ZFO with different crystallite sizes ranging from 10 nm to 25 nm. The transmission electron microscope (TEM) images showed well dispersed nanoparticles and a strong correlation of grain size growth with annealing temperature was established. The optical absorption and emission characteristics were estimated through UV–visible and Photoluminescence (PL) spectroscopy. Raman spectroscopy and X-ray Photoelectron Spectroscopy (XPS) confirmed the variation of oxygen vacancies in the synthesized samples’ lattice. The photocatalytic activities of all samples were investigated and the highest efficiencies were recorded for the ZFO samples annealed at 500 °C. Under high salinity condition, the organic dye degradation efficiency of the same sample remained the highest among all. The excellent dye degradation abilities in ZFO samples can be attributed to the abundance of oxygen vacancies in the crystal lattice that slow down the recombination rate during the photocatalysis process. Moreover, cytotoxicity tests revealed that all prepared ZFO samples showed insignificant cell structure effects on Picochlorum sp microalgae, as verified by Fourier-transform infrared (FTIR) spectroscopy. On the other hand, no significant changes were detected on the viable cell concentration and Chlorophyll a content. This work presents a systematic way to finely tune the crystal sizes and to modulate oxygen related defects in ZFO through a highly effective annealing approach to signify their potential in industrial wastewater and seawater treatment processes.

Chemosphere, Volume 288, Part 3, February 2022, 132606

Abstract

Nanotechnology is being an emerging science for wastewater treatment requires more research emphasis and depth knowledge. For wastewater treatment, different forms of nanomaterials are used based on the type of contaminants and treatment efficiency desired. With the development in the field of nanomaterials, novel and emerging nanomaterials are coming into existence. The nanomaterials used for wastewater treatment can be carbon, single-walled carbon nanotubes, multiple walled carbon nanotubes, covalent organic frameworks, metal and metal oxide- based nanoparticles. Graphene based nanoparticles, their oxides (GO) and reduced graphene oxide (rGO) find tremendous applicability to be used in wastewater treatment purposes. Due to the introduction of graphene oxide nanoparticles in the adsorbent materials, their adsorption capacities have get enhanced and such materials have also improved the mechanical stability of the adsorbent. Ferric oxide shows greater adsorption capacities for organic pollutants. Furthermore, magnetic nano-powder confers a low adsorption capacity for phenols. Pyrrolidone reduced graphene oxide (PVP-RGO) nanoparticles have been used as adsorbents for the elimination of inorganic target contaminant copper, with great adsorption (1698 mg/g). The present study comprehensively reviews nanotechnology as a wastewater treatment strategy besides enlightening its safety issues and efficiency. The novelty of this article is that it highlights the overview of recent applications of various types of nanomaterials and research works releated to it. Such an approach will be helpful to get insights into technological advances, applications and future challenges of nanotechnology implementation for wastewater treatment.

Chemosphere, Volume 288, Part 3, February 2022, 132647

Abstract

Missing data imputation and automatic fault detection of wastewater treatment plant (WWTP) sensors are crucial for energy conservation and environmental protection. Given the dynamic and non-linear characteristics of WWTP measurements, the conventional diagnosis models are inefficient and ignore potential valuable features in the offline modeling phase, leading to false alarms and inaccurate imputations. In this study, an inclusive framework for missing data imputation and sensor self-validation based on integrating variational autoencoders (VAE) with a deep residual network structure (ResNet-VAE) is proposed. This network structure can automatically extract complex features from WWTP data without the risk of vanishing gradients by learning the potential probability distribution of the input data. The proposed framework is intended to increase the reliability of faulty sensors by imputing missing data, detecting anomalies, identifying failure sources, and reconstructing faulty data to normal conditions. Several metrics were utilized to assess the performance of the suggested approach in comparison with other different methods. The VAE-ResNet approach showed superiority to detect (DRSPE = 100%), reconstruct faulty WWTP sensors (MAPE = 15.41%–5.68%) and impute the missing values (MAPE = 10.44%–3.98%). Lastly, the consequences of faulty data, missing data, reconstructed and imputed data were evaluated considering electricity consumption and resilience to demonstrate the ResNet-VAE model's superior performance for WWTP sustainability.

Chemosphere, Volume 288, Part 3, February 2022, 132655

Abstract

To understand how Cd in different fractions contributes to Cd bioaccessibility by in vitro assays, Cd bioaccessibility in 12 contaminated soils was determined by four assays (UBM, SBRC, IVG, and PBET) and correlated with different Cd fractions based on a sequential extraction scheme. The Cd bioaccessibility in the gastric phase (GP) was high (35–107%, averaging at 77%), implicating high risk to human health, while it decreased to 19–88% averaging at 47% in the intestinal phased (IP). From the GP to IP, the reduction of extractable Cd (0.45–48 mg kg−1) and Fe (118–3884 mg kg−1) showed significant correlation (R = 0.54–0.74) via UBM, SBRC, and IVG, suggesting co-precipitation with Fe and/or sorption onto Fe oxides maybe responsible for decrease in Cd bioaccessibility. Although Cd bioaccessibility varied among assays, their results show some consistency based on their correlation in the GP (R = 0.56–0.90) and IP (0.34–0.73, excluding UBM-IP and PBET-IP). Sequential extraction data show that Cd was primarily associated with the exchangeable fraction (E1; 7.05–72.9%, averaging 39.4%). The carbonate (C2; 6.86–44.8%, 21.9%) and Fe/Mn oxides fraction (F3; 12.5–53.6%, 28.2%) were similar, while organic (O4; 0.62–25.0%, 7.91%) and residual fraction (R5; 0.22–8.54%, 2.62%) were the lowest. Significant correlation (R = 0.59–0.88) between the first two fractions (E1+C2) and bioaccessible Cd suggest they were the main sources of bioaccessible Cd in those contaminated soils.