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Efficiently Removing Dissolved Organic Pollutants in Landfill Leachate Concentrate Using Dual-Anode Fe2+/Hclo System: The Significance of Insolubilization Based On Oxidative Coupling of Organics

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SSRN 2023年

作者： Liang, Sheng Wang, Jinling Shen, Zhizhi Yan, Wei Nengzi, Lichao Feng, Chunhua Yu, Li Hu, Junqing College of Health Science and Environmental Engineering Shenzhen Technology University Shenzhen518118 China Faculty of Chemical Engineering Kunming University of Science and Technology Kunming650500 China State Environmental Protection Key Laboratory of Managing Technology of Drinking Water Source Shenzhen Academy of Environmental Science Shenzhen518001 China Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of Education School of Environment and Energy South China University of Technology Guangzhou510006 China

The strategy to mineralize dissolved organics for the decontamination of landfill leachate concentrate (LLC) is expensive. Because mineralization requires high stoichiometric ratio of oxidants (e.g., •OH) or electron transfer (i.e., energy) to the pollutants molecular. Whereas, transferring the dissolved organic pollutants into separable insoluble matters is an energy-saving strategy. Herein, we developed a dual-anode Fe2+/HClO system for removing dissolved organic pollutants in LLC through insolubilization based on oxidative coupling. In this system, the majority of dissolved organic pollutants were transferred into insoluble substances, which could be removed easily. 89.8% of the dissolved organic carbon (DOC) in LLC was fast removed in 3 hours with a low specific energy consumption (SEC, 4.0 kWh kg-1 COD and 17.6 kWh kg-1 DOC), and the formation of toxic by-products can be well controlled. Interestingly, the formation of insoluble substances was predominantly attributed to the oxidative coupling of organic small molecules into the macromolecular ones. This was evidenced by the generation of insoluble compounds with the larger molecular mass (evidenced by mass spectrums), and the formation of coupling or polymerization products of the model pollutant (guaiacol). Specifically, the macromolecular matters were derived from the organic radicals (evidenced by EPR tests) coupling with each other. It was reported that Fe2+/HClO reaction produced reactive Fe(IV) under acid condition. According to the investigations in this work, we propose it is possibly because Fe(IV) was generated in the dual-anode Fe2+/HClO system, and Fe(IV) oxidized pollutants to produce the organic radicals. This work offers a novel electrochemical method for efficient removal of organic pollutants in LLC with minimal toxic by-products generated, and revealed the significance of oxidative coupling process in the electrochemical Fe2+/HClO system. © 2023, The Authors. All rights reserved.

关键词： Organic pollutants

Novel magnetic adsorbents based on oyster and clam shells for the removal of cadmium in soil

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Science of the Total Environment 2024年 955卷 177083页

作者： Wang, Heng Fu, Yuanqi Guo, Kexin Li, Xiaofei Jin, Xiaohu Huang, Yajing Wang, Xiaoyao Lu, Guining Yi, Xiaoyun Dang, Zhi School of Environment and Energy South China University of Technology Guangzhou510006 China The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of Education South China University of Technology Guangzhou510006 China School of Environmental and Chemical Engineering Foshan University Foshan528000 China Guangdong Yuegang Water Supply Co. Ltd. Shenzhen518021 China

Magnetic adsorbents can effectively remove heavy metals from soil. However, the magnetization process may reduce availability of adsorption sites, making it challenging to balance magnetic and adsorption properties. In this study, oyster shell (OS) and clam shell (CS) material was magnetized by an improved chemical co-precipitation method. The organic matter in the shells was destroyed by calcination modification to expose new active sites, and calcinated ferro-magnetic adsorbent was produced with either ferrosodium EDTA (giving CEOS and CECS) or with iron citrate (for CCOS and CCCS). All four modified adsorbents reached adsorption equilibrium for Cd2+ in solution within 120 min, with maximum adsorption capacities ranging from 115.5 to 266.5 mg/g, giving high removal efficiencies for Cd2+. Adsorption by precipitation and cation exchange mechanisms was dominant, together contributing >60 % of all adsorption capacity, followed by complexation. When used for remediation of Cd-contaminated soil, CEOS demonstrated the best Cd removal efficiency, achieving removal rates of 46 % and 58 % for total and available Cd, respectively. This was mainly because CEOS had the highest magnetic recovery rate, of 98 %. CEOS maintained removal rates of 34 % for total Cd after regeneration and reuse three cycles, with recovery rates remaining above 90 %. Contaminated soil was treated with the novel adsorbents and in pot experiments with water spinach cultivation it was shown that both CEOS and CECS treatment significantly reduced Cd content (by up to 56 %). The magnetic adsorbents presented here demonstrate excellent performance to remove Cd from water and soil, and have promising application prospects. © 2024

关键词： Shellfish

Sustainable Regeneration of Deactivated Hydrochar-Supported Ni Catalyst for Enhancing Low-Temperature Tar Reforming Performance

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SSRN 2024年

Catalytic tar reforming through biochar-supported nanoparticle catalyst has become a hot topic in biomass conversion;however, the deactivation of catalysts still remains a fundamental challenge. The deactivation and regeneration studies for pyrochar-based catalysts upon high temperature (700-900 oC) tar reforming has gathered momentum in recent years, yet the deactivation and regeneration mechanism of the hydrochar-based catalysts under low temperature reforming of biomass tar (e.g., 600 oC), still remain elusive so far. Here we report the facile N2 regeneration treatment (30 mL/min for 30 min) for the deactivated hydrochar-supported Ni catalyst facilitate the tar reforming activity and enhance the stability, by leveraging oxidization towards coke/hydrochar support hindrance, in an effort to alleviate the coke deposition as well as suppress metal sintering without compromising its reforming activity toward tar molecules than other regeneration atmospheres, including CO2, O2 and Air. Our findings bring new understanding of the deactivation and regeneration mechanism of the hydrochar-based tar reforming catalysts, and enable an economically and industrially viable path for biomass conversion. © 2024, The Authors. All rights reserved.

关键词： Biomass

Influence of Inorganic Nitrogen sources On High Sulfur Coal Bio-Desulfurization: Promoting Pyrite Bioleaching and Surface Effects

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SSRN 2022年

作者： Ye, Junpei Zubair, Muhammad Jia, Shiya Zhang, Panyue Cai, Yajing Wang, Qingyan Beijing Key Lab for Source Control Technology of Water Pollution College of Environmental Science and Engineering Beijing Forestry University Qinghua East Road 35 Haidian District Beijing100083 China School of Environment Henan Normal University Henan Xinxiang453007 China

Exotic microorganisms collected from sewage sludge was used for high sulfur coal biodesulfurization without culture medium addition, and the effect of NO3- and NH4+ on coal biodesulfurization was investigated. The biodesulfurization was significantly inhibited with NO3- addition, but enhanced with the NH4+ addition, the optimal dosage of (NH4)2SO4 is 6 g/L. After biodesulfurization for 30 days, the pyritic sulfur decreased from 2.854% to 0.261%, and the content of nitrogen slightly increased from 0.973% to 1.006%, the NH4+ addition was benefit for biologic removing populate elements. NH4+ could promote bioleaching microorganisms and enhance the indirect bioleaching at the beginning of biodesulfurization. The ammonium jarosite generation might break the pyrite surface and promote the bioleaching at the first 6 days but subsequently decrease the available pyrite surface, which inhibited bioleaching. In addition, during biodesulfurization, the NH4+ was not fully bio-adsorbed by microorganisms and may increase the chemical leaching of pyrite. © 2022, The Authors. All rights reserved.

关键词： Coal

Methylene blue (MB) removal from aqueous solution by alum;catalytic ozonation process

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Discover Chemical Engineering 2024年第1期4卷 1-17页

作者： Ikhlaq, Amir Parveen, Sehrish Raashid, Muhammad Masood, Zafar Rizvi, Osama Shaheen Al Johani, Thamer Abdulhameed Ahsan, Muffakir Amjad, Hadeeqa Qi, Fei Institute of Environmental Engineering and Research (IEER) University of Engineering and Technology (UET) Lahore Pakistan Department of Chemical Polymer and Composite Materials Engineering University of Engineering and Technology Lahore New Campus Lahore Pakistan Department of Chemistry and Chemical Engineering Syed Babar Ali School of Science & Engineering (SBASSE) Lahore University of Management Sciences (LUMS) Lahore Pakistan Environmental Protection and Control Department Royal Commission Jazan Jazan Saudi Arabia Saudi Arabian Parsons Limited Madinah Saudi Arabia Beijing Key Lab for Source Control Technology of Water Pollution College of Environmental Science and Engineering Beijing Forestry University Beijing People’s Republic of China

Textile wastewater is among the most polluted types of industrial waste. Wastewater treatment in the textile industry is notoriously difficult because of the use of complex chemicals and dyes in the textile production steps, and conventional methods are not enough to treat these. Textile wastewater, known for its high pollution levels, poses challenges for treatment due to complex chemicals and dyes. A comparative study was conducted on simple ozonation and catalytic ozonation (CO) using alum to degrade methylene blue (MB). The authors analyzed various factors like time, pH, catalyst loading and ozone dosages during the study. Results showed that catalytic activity in ozonation depends on pH and ozone flow. The maximum MB elimination was achieved at pH 6.6 and 200 V ozone flow. Scanning electron microscopy (SEM) was used to characterize the surface morphology of the catalyst, Fourier transform infrared spectroscopy (FTIR) was used to identify the important functional groups, and energy dispersive X-ray spectroscopy (EDS) was used to characterize the catalyst's elemental composition. Compared to simple ozonation, CO showed higher removal in the initial phase. Real textile wastewater analysis confirmed the effectiveness of alum catalysts in achieving significant removal of MB (87%) through this novel cost-efficient process.

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Experiments and Machine Learning-Based Modeling for Haloacetic Acids Rejection by Nanofiltration: Influence of Solute Properties and Operating Conditions

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SSRN 2023年

作者： Wang, Feifei Wang, Weikang Wang, Hongjie Zhao, Zilong Zhou, Ting Jiang, Chengjun Li, Ji Zhang, Xiaolei Liang, Tianzhe Dong, Wenyi School of Civil and Environmental Engineering Harbin Institute of Technology Shenzhen Shenzhen518055 China Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control Shenzhen518055 China State Key Lab of Urban Water Resource and Environment School of Civil and Environmental Engineering Harbin Institute of Technology Shenzhen Shenzhen518055 China Shen Zhen LiYuan Water Design & Consultation CO LTD China

Due to potential risks to public health, the presence of haloacetic acids (HAAs) in drinking water is a major concern. Nanofiltration (NF) showed potential for HAAs rejection and several factors including membrane properties, solute properties and operating conditions have been revealed key roles. However, the knowledge of NF separation mechanism by quantifying these factors is limited. This study aimed to investigate and model NF performance in HAAs rejection. NF performance was experimentally investigated under various pH, transmembrane pressure (TMP), cross-flow velocity (CV), ionic strength (IS) and temperature (Temp). To understand the mechanism from a perspective of HAAs properties and operating conditions, machine learning (ML) was used. Multiple linear regression (MLR), support vector machine (SVM), multilayer perceptron (MLP), extreme gradient boosting (XGBoost) and random forests (RF) models were applied to predict the rejection. MLP, XGBoost and RF models obtained significant performance with high R2 (0.977, 0.988 and 0.995) and low RMSE (4.2, 3.09 and 2.04). These three models were analyzed by Shapley Additive explanation (SHAP) to quantify relative contributions of HAAs properties and operating conditions. XGBoost-SHAP had the most logical results and was the best-performed model for optimal input variables combinations. The results showed decreasing contributions of partitioning coefficient (logKow), Stokes radius (rs), pH, Temp, molecular weight (MW) and TMP, as key variables to interpret NF process. The impacts of HAAs properties on rejection were ranked logKow > rs > MW, suggesting significance of hydrophobic interaction and size exclusion. The impact of operational conditions followed the order pH > Temp > TMP, illustrating pH was major influencing operating conditions. The results of this study showed great modeling capacity of ML, which can lessen amount of experimental work. Additionally, main operating conditions can be evaluated in terms of th

关键词： Forestry

Microbial source Tracking of Industrial Effluents Based on Sequencing Data

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SSRN 2022年

作者： Wei, Yan Li, Yumeng Wang, Yayu Luo, Xinyue Du, Feirong Liu, Weifang Xie, Li Chen, Jianwei Ren, Ziwei Hou, Shiqi Wang, Sunhaoyu Fu, Shaojie Dang, Yan Li, Pengsong Liu, Xin Beijing Key Lab for Source Control Technology of Water Pollution College of Environmental Science and Engineering Beijing Forestry University Beijing100083 China Engineering Research Center for Water Pollution Source Control & Eco-Remediation College of Environmental Science and Engineering Beijing Forestry University Beijing100083 China Co. Ltd. Shenzhen518000 China BGI-Shenzhen Guangdong Shenzhen518083 China Shenzhen Howay Technology Co. Ltd. Shenzhen518000 China BGI-Beijing Beijing100101 China Department of Gastroenterology

Microbial source tracking (MST) has been widely applied to discriminate human/non-human fecal pollution, and more recently sequencing-based MST has been proposed. However, it’s not clear whether we can use sequencing-based MST methods in tracking industrial effluents, which is usually fulfilled through monitoring chemical signatures. Here, we collected 28 sewage samples from the industrial effluents relative to four factories in Shenzhen, China, and sequenced the 16S rDNA to profile the microbial compositions. We depicted t he microbial diversity in the effluents to identify 5,413 operational taxonomic units (OTUs) in total. We found the microbial compositions to be highly diverse among samples from different locations in the sewer system, with only 107 OTUs to be shared among 90% of the samples. These shared OTUs were enriched in the phylum of Proteobacteria, the families of Comamonadaceae and Pseudomonadaceae , as well as the genus of Pseudomonas , with both degradation related and pathogenic bacteria. More importantly, we found microbes to be different among samples relevant to different factories, and we extracted microbial markers differentiating effluents from these factories, which can be used as MST markers to track the effluents. Our study proved the feasibility of industrial effluent tracking based on sequencing data, improved our understanding of microbial diversity in industrial effluents and provided an alternative technique solution for environmental surveillance and management. © 2022, The Authors. All rights reserved.

关键词： Sewage

New Insights and Reaction Mechanisms in the Design of Catalysts for the Synergistic Removal of Nox and Vocs from Coke Oven Flue Gas: Dual Regulation of Oxidative Properties and Acidic Sites

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SSRN 2024年

作者： Chen, Zimo Zhao, Cheng Wei, Ninghan Yun, Junge Chu, Rencheng Zheng, Han Feng, Xin Tong, Zhangfa Chen, Zhihang Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology School of Chemistry and Chemical Engineering Guangxi University Nanning530004 China Guangdong Key Lab of Water & Air Pollution Control Guangdong Province Engineering Laboratory for Air Pollution Control South China Institute of Environmental Sciences Ministry of Ecology and Environment Guangzhou510655 China College of Environment and Resources Xiangtan University Xiangtan China Department of Chemistry School of Chemistry and Chemical Engineering Northwestern Polytechnical University Xi'An China

The acid and redox sites of the MnCo catalysts were simultaneously fine-tuned by the addition of V. A dual-function catalyst, designated as V0.5Mn5Co5, has been constructed for the synergistic removal of NOx and volatile organic compounds under coke-oven flue gas conditions, which has more than 95% NOx conversion and more than 80% N2 selectivity at 180-300 °C and it removes 70% of ethylene at 240 °C. Besides it has excellent sulfur and water resistance. The characterization results demonstrated that this acid-redox site modulation strategy appropriately weakened the oxidation capacity of the catalysts while increasing the surface acidity of the catalysts. The catalysts mainly perform SCR reaction through E-R mechanism, and N2O is generated through the transition dehydrogenation of NH3 and NSCR reaction. Ethylene(C2H4) adsorption by the catalyst, oxidative formation of carbonate species with metal elements on the surface, and finally decomposition to CO2. There was a competitive adsorption of NH3 with C2H4, and there was a mutual inhibition between the SCR reaction and the ethylene oxidation reaction. V0.5Mn5Co5 exhibits excellent synergistic removal of NOx and VOCs in coke oven flue gas compare with commercial VWTi catalysts, which indicating great promise for industrial application. © 2024, The Authors. All rights reserved.

关键词： Volatile organic compounds

Accurate calculation method for urban domestic sewage centralized collection rate based on water quality and quantity variations

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Journal of Cleaner Production 2025年 516卷

作者： Lingwu Zeng Dezhi Sun Beijing Key Lab for Source Control Technology of Water Pollution Engineering Research Center for Water Pollution Source Control & Eco-remediation College of Environmental Science and Engineering Beijing Forestry University Beijing 100083 China National Joint Research Center for Ecological Conservation and High Quality Development of the Yellow River Basin Beijing 100012 China

Rapid urbanization has created significant challenges for domestic sewage management, particularly in accurately assessing sewage collection rate. A systematic analysis of globally adopted indicators for assessing sewage collection reveals a key limitation of existing calculation methods: they do not adequately account for variations in water quality and quantity within sewer networks, leading to biased results. To address this issue, this study proposes a new method for calculating the sewage collection rate. This method incorporates two key parameters-external water BOD 5 concentration and sewer BOD 5 degradation rate-to quantify external water infiltration, and to capture the effects of water quality and quantity variations on sewage collection rate. Applying this method, the domestic sewage centralized collection rates were calculated to range from 83.29 % to 90.67 % in Changzhou and from 76.40 % to 81.88 % in Shenzhen. Sensitivity analysis showed that the sewer BOD 5 degradation rate and the external water BOD 5 concentration affected the results by 0.25 and 0.042, respectively. Based on these findings, we propose several strategies to improve calculation accuracy, including developing a BOD 5 degradation rate model, deploying smart drainage systems, establishing cross-sector data-sharing platforms, and formulating standardized guidelines for calculating sewage collection rate. This study provides theoretical support for global sewage management.

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