Water Quality Research Journal
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2024
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IF 2.4
Yao Tangchun,Chen Yichao,Wu Wenting,Jin Binbin,Xiao Hua,Wang Qing,Wang Ao,Xu Hang
In this study, we utilized direct ultrafiltration (UF) and integrated microflocculation–ultrafiltration (MF–UF) processes to treat raw water from four distinct sources, covering both dry and heavy rainfall periods. We assessed the effectiveness of microflocculation (MF) as a pretreatment to enhance treatment efficiency under complex water conditions, focusing on its role in mitigating membrane fouling. The results demonstrated the superior adaptability of UF membranes when combined with MF pretreatment, particularly in managing high turbidity during heavy rainfall, a challenge for standalone UF processes in meeting regulatory standards. This integrated approach notably improved UV254 removal efficiency from approximately 60–80%. Additionally, excitation–emission matrix spectroscopy revealed that while the MF–UF process is effective in removing dissolved organic matter (DOM), it faces limitations with high DOM concentrations in raw water. Comparative analysis of membrane flux between the two methods showed that MF pretreatment reduces filtration time, enhances flux rates, and significantly decreases membrane fouling. Finally, scanning electron microscopy further provided insights into the structure and morphology of UF membrane surface filter cakes, illustrating how MF pretreatment contributes to the sustained efficiency of membrane flux. The different water quality conditions were studied. The MF–UF process was studied in realistic conditions. Organic matter and hard particulate matter were studied. Elucidating mechanisms to the MF–UF membrane flux efficiency.
研究领域:
环境科学
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水处理工程
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2024
·
IF 12.2
Cholnam Ri,Munchol Kim,Hyokchol Mun,Linan Liu,Jingchun Tang
Dissolved organic matter (DOM), which is ubiquitously distributed in groundwater, has a crucial role in the fate and reactivity of iron materials. However, there is a lack of direct evidence on how different DOMs interact with nFe/Ni in promoting or inhibiting the dechlorination efficiency of chlorinated aromatic contaminants. By comparing humic acid (HA), fulvic acid (FA), and biochar-derived dissolved organic matter (BDOM) at different pyrolysis temperatures, we first demonstrated that the dechlorination effect of nFe/Ni on 2,4-dichlorophenol (2,4-DCP) depended on the nature of DOMs and their adsorption on nFe/Ni. HA showed an enhancing effect on the dechlorination of 2,4-DCP by nFe/Ni, while the inhibition effect of other DOMs resulted in the following dechlorination order: BDOM300 ≈FA>BDOM700 ≈BDOM500. The C2 component with higher aromaticity and molecular weight promoted the corrosion of nFe/Ni and the production of reactive hydrogen atoms (H*). The effects of different DOMs on nFe/Ni include that (1) HA accelerates the corrosion and H* production of nFe/Ni, (2) FA and BDOM300 enhance the corrosion but inhibit H* production, and (3) Both nFe/Ni corrosion and H* formation are suppressed by BDOM500/BDOM700. Therefore, this study will provide a reference for understanding the nature of DOM-nFe/Ni interaction and improving the catalytic activity of nFe/Ni when different DOMs coexist in practical applications.
研究领域:
环境科学
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化学工程
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水处理
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DOI
PubMed
高影响因子
Membranes
·
2024
·Vol. 14
·期 6
·125
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IF 3.3
Qingao Li,Lixin Xie,Shichang Xu,Wen Zhang
The removal of dissolved organic matter (DOM) from seawater before the reverse osmosis (RO) processes is crucial for alleviating organic fouling of RO membranes. However, research is still insufficiently developed in the comparison of the effectiveness of integrating coagulation with ultrafiltration (UF) or sand filtration (SF) in the pretreatment stage of seawater reverse osmosis (SWRO) for the removal of DOM. In this study, we investigated the effect of pretreatment technologies on RO fouling caused by DOM in seawater, including the integration of coagulation and sand filtration (C-S pretreatment) and the integration of coagulation and ultrafiltration (C-U pretreatment). Both integrated pretreatments achieved comparable DOM removal rates (70.2% for C-U and 69.6% for C-S), and C-S exhibited enhanced removal of UV-absorbing compounds. Although C-U was more proficient in reducing the silt density index (below 2) compared to C-S (above 3) and improved the elimination of humic acid-like organics, it left a higher proportion of tyrosine-protein-like organics, soluble microbial by-product-like organics, and finer organics in the effluent, leading to the formation of a dense cake layer on RO membrane and a higher flux decline. Therefore, suitable technologies should be selected according to specific water conditions to efficiently mitigate RO membrane fouling.
研究领域:
环境科学
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水处理工程
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Quan Chen,Hongjuan Feng,Jihong Dong,Yu Huang,Peng Yi,Min Wu,Bo Pan
Sorption and degradation occur simultaneously during the removal of aromatic organics by biochar. However, the unclear association between sorption and degradation limited our understanding of the underlying mechanisms of organic removal by biochars. Herein, the removal of monocyclic 2,6-dimethylphenol (DMP) and bicyclic bisphenol A (BPA) by raw and potassium hydroxide modified biochars was comparatively investigated by batch removal experiments and theoretical calculations. Under identical initial concentrations, biochar displayed lower sorption but higher degradation for DMP compared to BPA, whilst higher sorption corresponded to greater degradation for the same chemical. Sorption mechanisms revealed by molecular dynamic simulations include π-π, hydrophobic, and hydrogen bonding interactions. Density functional theory calculations identified the preferred degradation sites on biochar for adsorbed organics are graphitic nitrogen, defects, carboxyl, and hydroxyl functional groups. Analysis of free radicals and degradation intermediates concluded that the degradation pathways involve both free radical pathways and electron transfer processes for DMP, while only free radicals for BPA. Experimental and computational results indicated an increase in ring quantity can lead to higher sorption affinity but lower degradability of aromatic organics by biochar. Findings of this research provide theoretical support for the advancement of biochar based aromatic contaminant mitigation strategies.
研究领域:
环境科学
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化学
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DOI
高影响因子
Frontiers of Environmental Science & Engineering
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2025
·Vol. 19
·期 7
·1-16
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IF 6.4
Yin Wenxuan,Sun Wenjun,Yuan Yongqin,Zhang Daoyi,Zhang Yuanna,Zheng Fengyi
UV/H 2 O 2 is commonly used to remove organic micropollutants and frequently paired with activated carbon for further removal of pollutants, addressing issues such as H 2 O 2 residuals, uncontrollable by-products, and energy consumption reduction. Here, we report the changes in the removal characteristics of organic contaminants during the operation of a pilot system based on UV/H 2 O 2 coupled granular activated carbon (GAC) after in situ biofilm formation to generate biologically activated carbon (BAC). We completed the screening of unknown organic matter and molecular-level chemical transformation of 100–1600 Da dissolved organic matter (DOM) using Fourier transform high-resolution mass spectrometry (FT-ICR MS). The FT-ICR MS results indicated that BAC differs from GAC in terms of DOM removal behavior and mechanisms. GAC primarily produces free radicals through synergistic residual H 2 O 2 to further oxidize and remove organics. Low molecular weight (LMW) organics undergo general molecular chemical changes but have modest removal effects. BAC considerably lowered the chemical variety of DOM and eliminated LMW organics through biodegradation and activated carbon adsorption. According to the study findings, UV/H 2 O 2 -BAC can more effectively compensate for the drawbacks of individual technologies than UV/H 2 O 2 -GAC, with superior removal efficiency of organic pollutants, no residual H 2 O 2 , controllable effluent products, and robust performance in real environmental matrices.
研究领域:
环境科学
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水处理工程
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DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2020
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IF 6.551
Minhua Su,Zequan Liu,Gutha Yuvaraja,Tao Ou,Ying Huang,Xiaoting Hu,Diyun Chen
Contamination caused by radionuclides such as uranium (U) has become an increasingly serious environmental problem. The unique and diverse features of uranyl ions (U(VI)) remarkably dominate their mobility and environmental impact on the ecosystem. Understanding the sorption behavior and fate of aqueous U(VI) ions on natural mineral(s) such as quartz sand (a typical type of crystalline silica (SiO 2 )) particles is essential for unraveling many environmental issues . In this work, the sorption of uranyl ions by various particle size quartz sands under different reaction conditions was thoroughly investigated. The quartz sand with an average particle size of 3.588 μm exhibited an excellent sorption performance for the removal of aqueous U(VI) ions at pH 5.0. The sorption rate increased as the dosage of sorbent increased. The sorption rate descends with the rise of the initial U(VI) concentration while its sorption amount is reversed. The elevation of temperature impeded the U(VI) sorption. Humic acid (a typical natural organic matter) showed significant impacts on U(VI) removal. Ions of Ca 2+ , CO 3 2− and K + remarkably inhibited the U(VI) sorption, while PO 4 3− ions significantly promoted the U(VI) sorption. The pseudo second-order kinetic model could fit well with the experimental sorption data. The U(VI) sorption is mainly chemisorption and it is an exothermic process. After sorption, the surface of used quartz sand became much smooth and XPS signals of U(VI) were detected, evidencing the success of the removal of aqueous U(VI). The outcomes of this study highlighted both solution pH and natural organic matters played critical roles on U(VI) removal by sand particles. This study further enhances our comprehension from the molecular-scale process manipulating U(VI) sorption behavior at the mineral-aqueous interface.
研究领域:
环境科学
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放射化学
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DOI
PubMed
高影响因子
Coatings
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2022
·Vol. 12
·期 3
·366
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IF 3.236
Shengping Zhang,Chen Yu,Jingyi Tan,Yuxin Wang,Zhen He
In this study, Ti/SnO2-Sb2Ox-TiO2electrodes were produced using a sol-enhanced electrodeposition technique from methanesulfonate electrolytes. The surface microstructures of Ti/SnO2-Sb2Ox-TiO2were observed, and their phase constituents were determined. The surface features were analyzed by X-ray photoelectron spectroscopy. Linear sweep voltammetry and degradation tests were also conducted to determine the degradation performance. The results show that the addition of TiO2sol affects the microstructures of Ti/SnO2-Sb2Ox-TiO2electrodes, while a uniform coating surface can be obtained at a proper sol concentration in electrolytes. Adding TiO2sol also causes deep oxidation of Sb and generates more adsorbed oxygen on the electrode surface. The favorable surface features and the well-dispersed TiO2in the coatings of 10 mL/L TiO2modified Ti/SnO2-Sb2Ox-TiO2electrodes award them the best electrocatalytic performance, and their uniform coating surface prolongs the electrode service life.Keywords:SnO2-Sb2Ox;sol-enhanced electrodeposition;organic degradation
研究领域:
材料科学
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环境科学
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DOI
高影响因子
Nanomaterials
·
2023
·Vol. 13
·期 7
·1189
·
IF 5.3
Qingtao Li,Qi Cai,Xiaoyun Li,Enshan Han,Yanmin Sun,Yanfei Lu,Zhe Cai,Haibin Yu
To screen a suitable precursor, the effects of palladium salts on performance of Pd nanocatalysts for the oxidation of volatile organic components (VOCs) were investigated. A series of catalysts was prepared by impregnating Pd(NO3)2, PdCl2and Pd(NH3)4Cl2on alumina-coated cordierites. These catalysts were characterized by XRF, ICP-OES, XRD, N2adsorption-desorption, TEM, EDS, Raman spectroscopy, pulse-CO chemisorption, H2-TPR, NH3-TPD, and XPS. Pulse-CO chemisorption and TEM showed that Pd species formed by Pd(NO3)2have the highest metal dispersion (17.7%), while the other two were aggregating. For the same Pd loading, the higher the metal dispersion, the more the number of PdO species, so the number of PdO particles in the catalyst prepared from Pd (NO3)2is the largest. The catalytic oxidation activities of these catalysts were evaluated by ethane and propane. Based on a 99% conversion in the oxidation of ethane and propane at 598 K and 583 K, respectively, the catalyst prepared from Pd(NO3)2was considered to be the best performing catalyst. The chloride species in precursors can promote the aggregation of Pd species and poison the catalysts. The results show that Pd(NO3)2is more suitable as the precursor of VOC oxidation catalyst than PdCl2and Pd(NH3)4Cl2.Keywords:volatile organic components;palladium;catalytic oxidation;precursors
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
Journal of Environmental Sciences
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2018
·
IF 3.12
Fan Bu,Baoyu Gao,Qinyan Yue,Xue Shen,Wenyu Wang
Coagulation–ultrafiltration (C–UF) is widely used for surface water treatment. With the removal of pollutants, the characteristics of organic matter change and affect the final treatment efficiency and the development of membrane fouling . In this study, we built a dynamic C–UF set-up to carry out the treatment of micro-polluted surface water, to investigate the characteristics of dissolved organic matter from different units. The influences of poly aluminum chloride and poly dimethyldiallylammonium chloride (PDMDAAC) on removal efficiency and membrane fouling were also investigated. Results showed that the dosage of PDMDAAC evidently increased the UV 254 and dissolved organic carbon removal efficiencies, and thereby alleviated membrane fouling in the C–UF process. Most hydrophobic bases (HoB) and hydrophobic neutral fractions could be removed by coagulation. Similarly, UF was good at removing HoB compared to hydrophilic substances (HiS) and hydrophobic acid (HoA) fractions. HiS and HoA fractions with low molecule weight accumulated on the surface of the membrane, causing the increase of transmembrane pressure (TMP). Membrane fouling was mainly caused by a removable cake layer, and mechanical cleaning was an efficient way to decrease the TMP.
研究领域:
环境工程
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水处理技术
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膜分离
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有机地球化学
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给水处理
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DOI
高影响因子
CHEMOSPHERE
·
2019
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IF 5.108
Fan Bu,Baoyu Gao,Xue Shen,Wenyu Wang,Qinyan Yue
Ultrafiltration (UF) technology is considered an efficient water treatment method. In recent years, researchers have been committed to enhancing the treatment efficiency of UF and alleviating membrane fouling. An effective method is to achieve this is through the use of coagulation as a pre-treatment to UF; however, during a long term operation, membrane fouling can occur due to the residual organic matters and the generation of microorganisms . In this study, we combine coagulation and ozonation as a pre-treatment of UF and compare four types of pre-treatment: coagulation, ozonation, coagulation followed by ozonation (C–O) and ozonation followed by coagulation (O–C). Results showed that ozonation alone did not perform well. Both combinations of coagulation and ozonation enhanced the organic matter removal efficiency, although membrane fouling was lowest following the C–O pre-treatment as the microbial load was reduced. While a slight increase in the yield of disinfection by-products was observed with the addition of ozonation, the concentration remained below the Chinese standard for tap water quality (100 μg/L).
研究领域:
环境科学
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水处理工程
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2023
·
IF 8.3
Junjun Ma,Tao E,Shuyi Yang,Liang Chen,Ying Cheng,Jia Yu,Yun Li
Stabilizing Cr(III) in tannery sludge (TS) via harmless method has always been the goal of environmental pollution treatment. In this study, a simple method to stabilize Cr(III) in TS is proposed via adding kaolin, based on the fact a large amount of organic matter contained in TS. Comprehensive characterizations confirm that kaolin can stabilize Cr(Ⅲ) via its abundant –OH and lamellar structure. Moreover, there are hydrogen bond interactions and ligand exchange-surface complexation between organic matter and kaolin, which is more conducive to form a stable ternary complex with Cr(III), in a state of organic matter-Cr(III)-kaolin. Simultaneously, the BCR sequential extraction experiment shows that the unstable water and acid soluble state of Cr(III) are reduced (from 0.61% to 0.35%), which further indicates that the stabilization of Cr(III) is successful.
研究领域:
环境科学
·
污染治理
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Shuai Zhang,Jiating Zhao,Lizhong Zhu
Thermal desorption (TD) is known as an effective technique to remediate PAHs-contaminated sites. However, effectively removing PAHs using TD while saving time, and energy, and minimizing soil damage remains a challenge. In this study, we examined the combined effects of various factors on the removal efficiency of pyrene (PYR) by TD and developed an optimal numerical model based on conducting a series of soil experiments. The results showed that temperature (T) and time (t) promoted the desorption of PYR, while water ( S w ) and organic matter ( f om ) were just the opposite. Besides, water and organic matter had a synergistic effect proportionally. It was found that adjusting the soil-water ratio (which can be controlled by organic matter) maximized the desorption rate of PYR. An ideal S w / f om 1.56 and a minimized recommended temperature (173 °C) were proposed based on the model. Finally, the efficacy of the optimized scheme was validated in real-world site soil. These findings not only mechanistically revealed the desorption behavior of PYR under the influence of various factors, but also provided an optimized scheme for efficiently removing PAHs using TD, thereby accelerating the remediation process and reducing energy consumption. The modeling ideas and conclusions obtained may be applicable to other PAHs, guiding the effective remediation of PAHs-polluted sites.
研究领域:
环境科学
·
污染治理
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产品关联
DOI
PubMed
高影响因子
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