SCIENCE OF THE TOTAL ENVIRONMENT
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2024
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IF 8.2
Shengnan Chen,Zhiwei Zhao,Li Li,Fuyi Cui
Ultrafiltration (UF) is widely used in drinking water plants, nevertheless, it still encounters challenges stemming from inevitable membrane fouling caused by natural organic matter (NOM). Herein, this work applied VUV/PS as UF membrane pretreatment and used UV/PS for comparison. VUV/PS system exhibited superior ability in removing NOM compared to UV/PS system. HO and SO 4 − played crucial roles in the degradation. [SO 4 − ]ss was notably higher than [HO ]ss in the systems, yet HO was of greater significance. [HO ]ss and [SO 4 − ]ss in the VUV/PS process were remarkably higher than those in the UV/PS process, due to the function of 185 nm photons. VUV/PS pretreatment basically recovered flux and effectively reduced fouling resistance, with better performance than UV/PS. Fouling mechanism was dominated by multiple mechanisms after UV/PS pretreatment, whereas it was transformed into pore blockage after VUV/PS pretreatment. Moreover, the UF effluent quality after VUV/PS pretreatment outperformed that of UV/PS but fell short of that without pretreatment, possibly due to the generation of abundant low MW substances under the action of HO and SO 4 − . After chlorine disinfection, UV/PS and VUV/PS pretreatments increased the DBPs production and cytotoxicity. Specifically, oxidant PS affected the membrane surface morphology and fouling behaviors, and had no obvious effect on interception performance and mechanical properties. In actual water treatment, VUV/PS and UV/PS pretreatments exhibited excellent performance in alleviating membrane fouling, improving water quality, and reducing DBPs formation and acute toxicity.
研究领域:
环境科学
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水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
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2017
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IF 2.625
Feige Wang,Wenjing Wang,Shoujun Yuan,Wei Wang,Zhen-Hu Hu
Thiamphenicol (TAP) has been widely used in aquaculture to prevent bacterial diseases. However, this drug exhibits toxic side effects on the haemopoietic system. The removal of residual TAP in wastewater in advanced oxidation processes (AOPs) was rarely reported before. In this study, degradation of TAP in aqueous solution by UV alone, UV/H 2 O 2 and UV/PS processes was investigated. The results showed that UV/H 2 O 2 and UV/PS significantly enhanced the degradation compared to UV alone. The TAP degradation followed a pseudo-first-order kinetics pattern well. The k obs declined with the increase of the initial TAP concentration, and increased with increasing oxidant dosage. The TAP degradation with UV/H 2 O 2 process was favorable under neutral and acidic conditions, and with UV/PS process was favorable under acidic and alkaline conditions. HCO 3 − markedly inhibited the degradation with the both processes, NO 3 − had a slight inhibition on the degradation in UV/H 2 O 2 system, and Cl − significantly enhanced the degradation with UV/PS process. HA markedly inhibited the degradation with the both processes. SO 4 − played the main role in the TAP degradation by UV/PS process. When TAP was completely degraded, only part of TAP was mineralized with UV/H 2 O 2 process, and was totally mineralized with UV/PS process. The possible degradation pathways were proposed based on the intermediate products obtained by LC-TOF-MS analysis. The electrical energy per order (EE/O) analysis showed that UV/PS process was a less energy consumption process. The results from this study revealed that UV/PS process was a cost-effective process in the degradation of TAP.
研究领域:
环境科学
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药学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Water Process Engineering
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2024
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IF 6.3
Xinyi Li,Yan Li,Zhuo Wang,Tao Xu,Minqiang Hong,Xiaobin Zhao,Xuhui Mao
The dissolved organic matters in the membrane concentrates often cause scaling/blockage problems and significantly deteriorate the quality of the recovered salts when the evaporation crystallization process is used to treat membrane concentrates. It is important to find a cost-effective method to decrease the dissolved organic matters in concentrates. This study explores the feasibility of using an ultraviolet/peroxysulfate/ozone (UV/PS/O 3 ) process for the degradation of organic matters in nanofiltration membrane concentrates (NMCs). The UV/PS/O 3 process outperformed other processes, including UV photolysis alone, PS oxidation alone, UV/PS, and UV/O 3 , and achieved a complete oxidative degradation of 200 mg/L quinoline (QL) within 40 min in concentrated Na 2 SO 4 solutions. The experiments also revealed that OH and SO 4 − were the primary reactive radicals for QL oxidation in the UV/PS/O 3 process. QL removal efficiency increased along with the amount of aerated O 3 , the PS dosage, and was especially enhanced under a weakly alkaline condition. The response surface analysis showed that the optimal condition for QL removal was 4.68 mM PS, 3.43 mg/L O 3 gas, and pH ini 8.43. The presence of chloride ions (5–15 mM) inhibited the removal of QL. When the combination of UV/PS/O 3 process and evaporation crystallization was examined for the treatment of real NMC from a coking plant, it was found that the heating process could thermally activate the residual PS for the removal of organic impurity, and the whole process allowed to recycle sulfate salts with better brightness from the NMC. This study provides a prospective technology for the efficient treatment of NMC wastewater.
研究领域:
环境科学
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水处理工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
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2022
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IF 6.796
Jie Xu,Yang Guo,Qian Yang,Xueling Bai,Runhua Lu,Menghui Liu,Zichen Kuang,Luo Zhang,Jing Li
Ultraviolet/persulfate (UV/PS) and Ultraviolet/hydrogen peroxide (UV/H 2 O 2 ) have attracted much attention in recent years as advanced oxidation processes for water treatment. However, it is not all clear how these two methods affect the formation of cyanogen chloride (CNCl) in the subsequent water chlorination process. In this study, it was found that both UV/H 2 O 2 and UV/PS pre-oxidation promoted the formation of CNCl in six actual water samples collected from urban rivers. Glycine, uric acid, arginine and histidine were investigated as the model compounds to explore the effects of different methods on the production of CNCl. The results showed that compared with chlorination alone, pre-oxidation by UV/H 2 O 2 and UV/PS can reduce the production of CNCl for glycine and uric acid by up to 95% during post-chlorination process. However, they can greatly promote the formation of CNCl for arginine and histidine by up to 120-fold. In a more detailed investigation, pre-oxidation of histidine formed highly reactive intermediates to chlorine, leading to increased CNCl formation and chlorine consumption. The results showed that the precursors of CNCl was altered after pre-oxidation, and need to be re-evaluated.
研究领域:
环境科学
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水污染控制工程
✓ 已验证
DOI
PubMed
高影响因子
CHEMOSPHERE
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2018
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IF 4.427
Zongping Wang,Ying Wan,Pengchao Xie,Aijiao Zhou,Jiaqi Ding,Jingwen Wang,Li Zhang,Songlin Wang,Tian C. Zhang
The effects of ultraviolet/persulfate (UV/PS) pretreatment on ultrafiltration (UF) membrane fouling caused by typical natural organic matter (NOM) fractions including humic acid (HA), sodium alginate (SA), and bovine serum albumin (BSA) were investigated. UF membrane fouling during the filtration of different NOM fractions after UV/PS pretreatment was compared through the evaluation of normalized membrane flux decline and membrane fouling reversibility. The fouling mitigation mechanisms were investigated through the characterization of ultraviolet absorbance (UV 254 ), dissolved organic matter , zeta potential , particle size distribution , fluorescence excitation-emission matrix spectra, and fitness of four classic fouling models. Furthermore, the fouled membranes were characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy. The results showed that UV/PS pretreatment significantly alleviated membrane fouling caused by HA, SA, and HA-SA-BSA mixture, and the fouling control performance improved at high PS doses. However, either UV alone or UV/PS pretreatment at low PS dose (10 mg/L) significantly aggravated BSA fouling with the normalized flux at the end of first filtration cycle being 8% and 15%, respectively. The increased particle size of BSA after UV/PS pretreatment was attributed to the formation of aggregates, which mainly accumulated in membrane pores and aggravated membrane fouling. Modeling results suggest that the mitigation of membrane fouling derived from SA and mixed organic fractions was primarily ascribed to the control of cake filtration, while the mitigation of HA fouling was attributed to the declined contribution of standard blocking.
研究领域:
环境科学
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水处理工程
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膜技术
✓ 已验证
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2018
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IF 4.61
Min-Yong Lee,Wen-Long Wang,Zi-Bin Xu,Bei Ye,Qian-Yuan Wu,Hong-Ying Hu
Dodecyltrimethylammonium chloride (DTAC) is a quaternary ammonium compound (QAC) that is a widespread contaminant in environmental media and therefore of increasing concern. The synergistic effect with UV irradiation and persulfate (UV/PS) was used to degrade DTAC . The removal of DTAC was 91% with the PS dosage of 75.6 μM (UV/PS) and UV fluence of 870 mJ·cm −2 . The second-order rate constants of DTAC with HO and SO 4 − were determined to be k HO , DTAC (4.2 ± 0.18) × 10 9 M −1 s −1 and k SO 4 ∙− , DTAC (2.5 ± 0.27) × 10 9 M −1 s −1 , respectively. The contributions of HO and SO 4 − to DTAC degradation in the UV/PS were found to be 30% and 62% at pH 7, respectively. The contributions of SO 4 − and HO were not significantly influenced by acidic medium (pH 3–pH 7), whereas they were significantly affected by basic medium (pH 7–pH 11). The wastewater matrixes of HCO 3 − , Cl − and humic acid inhibited the DTAC elimination, whereas NO 3 − and SO 4 2− had no significant impact on its elimination. Moreover, the k obs,DTAC in the reverse osmosis influent (ROI) and reverse osmosis concentrate (ROC) were examined to be 0.04 to 0.1 min −1 and 0.02 to 0.05 min −1 , respectively, as the PS dosage increased from 18.9 to 113.4 μM. The inhibitive effects of matrix in ROI and ROC was 70% and 81%, respectively. The contribution of radical scavenging effect by matrix ROI and ROC was more significant to DTAC degradation than UV scattering effect in ROI and ROC matrices. A UV fluence of 1305 mJ·cm −2 was necessitated for complete detoxification and DTAC solution by UV/PS.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2016
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IF 5.31
Wenhai Chu,Dongmei Li,Yang Deng,Naiyun Gao,Yansen Zhang,Yanping Zhu
Free amino acids (AAs) can form trihalomethanes (THMs) and haloacetonitriles (HANs) during chlorination in drinking water treatment plants, but they account for a small fraction of dissolved organic nitrogen (DON) pool in natural waters. In contrast, combined AAs contribute to a greater identifiable DON portion, but the information on the formation and control of THMs and HANs from them is limited. Ultraviolet/hydrogen peroxide (UV/H 2 O 2 ) and ultraviolet/persulfate (UV/PS), two typical UV-based advanced oxidation processes (UV-AOPs), are both promising drinking water technologies for the reduction of trace organic contaminants . The objective of this study is to examine the effects of the two UV-AOP pre-treatments on the formation of carbonaceous and nitrogenous disinfection by-products (C- and N-DBPs), which were indicated by THMs and HANs, respectively, during post-chlorination and chloramination of tyrosine (Tyr) in free and combined forms. Results showed that direct UV photolysis, PS pre-oxidation alone or H 2 O 2 pre-oxidation alone did not significantly impact the THM and HAN formation during subsequent chlorination. However, the two UV-AOP pre-treatments could somewhat alter the DBP formation. In general, under the identical doses (UV irradiation dose and molar oxidant dose), UV/PS pre-treatment better controlled the HANs than UV/H 2 O 2 during AA post-chlorination, though UV/PS might slightly promote the formation of chloroform . In contrast, the two UV-AOP pre-treatments did not obviously affect the THM and HAN formation when post-chloramination was applied. In addition, a marked difference was observed in the speciation of DBPs formed from free AAs and short oligopeptides in the presence of bromide. For free Tyr, more brominated THMs were formed than brominated HANs; but for short oligopeptides, more bromine was incorporated into HANs than THMs.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）