SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Shangding Yang,Xiaoke Yan,Shitai Shen,Li Wu,Bolin Li,Liuyang He,Lijuan Wu,Zulin Zhang,Lie Yang
Although advanced reduction processes (ARPs) based on UV/S(IV) (UV/sulfite) processes could achieve higher dechlorination and degradation efficiencies for organic pollutants , the mineralization and detoxification efficiencies still need to be further improved. In this study, post-reoxygenation was employed to improve the mineralization and detoxification of chloramphenicol (CAP) in UV/S(IV)-ARPs. The effects of initial pH and aeration rate on the dechlorination and mineralization efficiency of CAP were investigated. At the optimized conditions (pH 3.0, aeration rate of 0.3 L min −1 ), 92.75 % of dechlorination efficiency and 29.3 % of COD removal were obtained after 2 h of reoxygenation. Meanwhile, the effects of inorganic anions (Cl - , SO 4 2- , HCO 3 – , NO 3 – , and HPO 4 2- ) on the removal of COD and dechlorination efficiency were also evaluated. Furthermore, the electron paramagnetic resonance analysis disclosed that SO 4 •- and HO • mainly contributed to the mineralization of CAP. Further degradation and mineralization of CAP were confirmed in the post-reoxygenation UV/S(IV)-ARPs (PRO-UV/S(IV)-ARPs) and the intermediates were identified. The ecotoxicity prediction and residual toxicity assessment revealed that the ecotoxicity of CAP solution was significantly reduced after the treatment of post-reoxygenation. Overall, the PRO-UV/S(IV)-ARPs provides a promising choice with straightforward operation for the purification and detoxification of CAP wastewater.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2023
·
IF 8.6
Xiaowei Liu,Peng Chen,Xiangdong Li,Jiaen Zhong,Kexin Li,Miaomiao Ye,Lili Wang
The widespread implementation of ultrafiltration (UF) technology, which has gained popularity for drinking water treatment, has been impeded by rising operational costs and shortened membrane lifespans resulting from membrane fouling. Here, an integrated pretreatment technique combining oxidation, adsorption, and coagulation was developed using the S(IV)–Fe(II) binary activated permanganate (PM) system, S(IV)–Fe(II)/PM. The efficacy of S(IV)–Fe(II)/PM pretreatment in mitigating UF membrane fouling was investigated for various raw water sources, including lakes, rivers, and seawater. The operational parameters of S(IV)–Fe(II)/PM pretreatment were optimized, and the underlying mechanisms for fouling alleviation were explored. Relative to conventional pretreatment methods, S(IV)–Fe(II)/PM pretreatment reduced reversible fouling-induced resistance by 13%–92% and irreversible fouling-induced resistance by 11%–86%. The S(IV)–Fe(II)/PM system exhibited optimal mitigation of membrane fouling at a PM:S(IV):Fe(II) dosage ratio of 2:3:3, with G rapid × T rapid = 45948, G slow × T slow = 12480, and a settling time of 30 min (where G is the velocity gradient and T is contact time). The effectiveness of S(IV)–Fe(II)/PM pretreatment in controlling UF membrane fouling can be attributed to the following mechanisms: 1) modification of feed water quality in terms of organic compound characteristics and concentration, colloidal particle quantity and size distribution, and microbial activity and quantity; and 2) adjustment of the membrane surface deposition environment, resulting in reduced polysaccharide and protein content, particle size distribution range, and biomass, as well as alterations in physicochemical properties such as hydrophilicity and interfacial free energy. This study highlights the efficacy of S(IV)–Fe(II)/PM pretreatment in ensuring high-quality UF effluent while effectively reducing membrane fouling, especially its potential for alleviating irreversible membrane fouling.
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2026
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IF 10.6
Haoran Hu,Guoyan Dang,Jiahe Shi,Junhao Cui,Shu Zhou,Yanrong Zhang
The reaction between hexavalent chromium (Cr(VI)) and sulfite (S(IV)) holds promise for water decontamination but intrinsically favors a non-radical pathway, leading to toxic Cr(V) accumulation and inefficient radical yields. Herein, we constructed a heterogeneous carbon/Cr(VI)/S(IV) advanced oxidation system using carboxyl-rich carbon materials (CP-T and MWCNTs-COOH) to steer the reaction toward a radical-dominated pathway. Combined experimental and theoretical analyses unravel a surface-mediated ligand-exchange activation mechanism. Surface carboxyl groups function as specific anchoring sites, undergoing ligand exchange with Cr(VI) species to form a reactive Carbon-COO-Cr(VI) intermediate. Concurrently, the highly conductive carbon framework serves as an efficient electron conduit, facilitating rapid interfacial electron transfer from S(IV) to the anchored Cr centers. A dual-descriptor kinetic model was established, quantitatively demonstrating that the catalytic turnover is governed by a symmetric co-limitation regime; the intrinsic catalytic activity of the carboxyl sites is non-linearly amplified by the enhanced electron transport capability of the carbon network. This synergistic interplay simultaneously achieves complete Cr(VI)-to-Cr(III) detoxification and efficient sulfate radical (SO 4 •− ) generation. Furthermore, density functional theory (DFT) calculations elucidated the SO 4 •− -initiated degradation pathways for diclofenac (DCF). Operating efficiently in authentic water matrices under near-neutral conditions, this work provides a scalable and sustainable strategy for the synergistic remediation of complex metal-organic co-contamination.
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DOI
PubMed
高影响因子
ACS Earth and Space Chemistry
·
2023
·
IF 3.4
Hao Tian,Xue-Bin Zhang,Yin-Ping Li,Qing He,Na-Na Tian,Song-Hai Wu,Xu Han
Although inorganic Fe(IV)═O oxo and Fe(III)-OOH peroxo have attracted more attention in aqueous environments, direct evidence for the characterization and identification of those oxidizing species is still lacking. In this study, the doped Cu/Co increases the reactivity of ferrihydrite/hematite in oxidizing As(III) by S(IV)-O2 under alkaline and dark conditions. Quenching experiments exclude the contributions of ·OH, O2•–, SO3•–, SO4•–, SO5•–, HSO5–, and H2O2 and confirm that peroxo and oxo are primary oxidizing species in As(III) oxidation. Electrochemical analyses indicate that Fe(IV)═O oxo and Fe(III)-OOH peroxo are primarily located on the surface of ferrihydrite and hematite. Selective oxidation of methyl phenyl sulfoxide and methyl phenyl sulfide to the corresponding oxidation products further reveals the presence of ≡Fe(IV)═O oxo on both ferrihydrite and hematite, and the doped Cu/Co significantly decreases the produced ≡Fe(IV)═O oxo on ferrihydrite, while increases the produced ≡Fe(IV)═O oxo on hematite. Meanwhile, selective oxidation of benzyl alcohol to benzaldehyde indicates the presence of ≡Fe(III)-OOH peroxo on both ferrihydrite and hematite, and the doped Cu/Co apparently increases the produced ≡Fe(III)-OOH peroxo on ferrihydrite and hematite. Raman analysis further reveals the presence of ≡Fe(IV)═O oxo and ≡Fe(III)-OOH peroxo on pure and metal-doped ferrihydrite/hematite, which also confirms that the doped Cu/Co decreases the produced ≡Fe(IV)═O oxo on ferrihydrite and increases ≡Fe(IV)═O oxo on hematite, while apparently increasing ≡Fe(III)-OOH peroxo on both ferrihydrite and hematite. This study enriches our understanding on the oxidizing species in the S(IV)-mediated oxidation processes under alkaline conditions, providing new insight on the oxidation reactivity of surface peroxo and oxo species mediated by the doped metal ions.
研究领域:
环境科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Kunyu Chen,Zhanguo Cui,Zhiqiang Zhang,Heliang Pang,Jing Yang,Xiaojiang Huang,Jinsuo Lu
The present study developed a prolonged oxidizable sulfur(IV)/ferrate(VI) system for the generation of hydroxyl radical ( OH) and sulfate radical (SO 4 − ) within 120 min, and proposed a reaction mechanism. In the presence of H + in solution, the S(IV)/Fe(IV) system provided excellent oxidation performance of refractory organics O,O-dimethyl-S-methylcarbamoyl methyl phosphorothioate (dimethoate, a widely used organophosphorus pesticide) within 120 min. The degradation efficiency of dimethoate in the bisulfite/Fe(VI) system (e.g., 90.06% dimethoate) was higher than that in the sulfite/Fe(VI) system (e.g., 51.03% dimethoate), while Fe(VI) alone degraded 27.81% of dimethoate. In the S(IV)/Fe(VI) system, the active species consisted of Fe(VI) (including the highly-reactive iron-based intermediate species, i.e. Fe(V) and Fe(IV)), OH and SO 4 − , with OH being identified as the main active species, contributing more than half of the total. The degradation mechanism of dimethoate in the S(IV)/Fe(VI) system mainly included the cleavage of the S-P bond, C-S bond and the oxidation of the P = S bond. Two plausible degradation pathways were proposed based on the detected transformation products. Dimethoate could be efficiently degraded when the [bisulfite]/[Fe(VI)] molar ratio was 4:1 with a low Fe(VI) dosage (218 µM), the changes in HA and HCO 3 − concentrations affected the transformation of dimethoate, the presence of Cl − , SO 4 2− and NO 3 − had a negligible effect, and the S(IV)/Fe(VI) system performed well in real waters. The S(IV)/Fe(VI) system has excellent oxidation performance for the removal of organic pollutants in water, with a final pH (pH = 6.6) close to neutral and ultimate products of SO 4 2− and Fe(OH) 3 , which has great potential for engineering applications.
研究领域:
环境科学
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水处理技术
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
·
IF 9.136
Hao Wang,Yongrong Zou,Tao Luo,Mehdi Benouahmane,Danna Zhou,Feng Wu
In recent years, a new strategy of using sulfite (S(IV)) to replace persulfates (peroxydisulfate (PS) and peroxybisulfate (PMS)) for sulfate radical based advanced oxidation process (SR-AOP) has emerged as one of the potential alternatives in the field of AOPs. Although the thermal activation of PS and PMS has been investigated extensively, that of S(IV) has not yet been explored. In this work, As(III) oxidation in a heat–S(IV) system was investigated first to demonstrate the feasibility of thermal activation of S(IV). Results showed that S(IV) can be activated to oxidize As(III) by heating the reactant solution from room temperature to above 50℃. Almost complete oxidation of 5 μM As(III) in water at pH 7 with addition of 1 mM S(IV) was achieved at 70 °C within 30 min. As(III) oxidation in the heat–S(IV) system was strongly dependent on the dissolved oxygen in water. Radical-scavenging experiments and electron spin resonance analysis demonstrated that the main active species responsible for As(III) oxidation was SO 4 •− . On the basis of thermal activation, a new system of SR-AOPs, namely, heat–electro-S(IV) system, the coupling thermal and electrochemical activations was established with ruthenium-plated iridium electrodes at a voltage of 3 V. It achieved complete oxidation of 50 μM As(III) in water at pH 7 at 50 °C with the addition of 2 mM S(IV) after reaction for 30 min. This work provides a new activation method for SR-AOPs with S(IV) as the precursor of reactive species and helps in understanding the reaction of S(IV) autooxidation.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2013
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IF 2.206
Tian Lan,Lecheng Lei,Bin Yang,Xingwang Zhang,Zhongjian Li
Kinetics of iron(II)- and manganese(II)-catalyzed oxidation of S(IV) in seawater were studied here to provide theoretical support for the flue gas desulfurization process (SFGD). Experiments were carried out with artificial seawater and acetic buffer. Results indicated that the reaction order with respect to dissolved oxygen is zero. However, the reaction order with respect to S(IV) is variable: second-order under uncatalyzed condition (4.0 ≤ pH ≤ 7.0); first-order under Fe(II)-catalyzed oxidation (2.5 ≤ pH ≤ 3.5); first-order (4.0 ≤ pH ≤ 5.0) and second-order (5.5 ≤ pH ≤ 5.9) under Mn(II)-catalyzed oxidation. The different S(IV) dependence could be attributed to different metal speciation at different pH values. Also, acetate is found to have significant inhibition effect on Mn(II)-catalyzed oxidation in high ion strength solution. The strong catalytic effect of Fe(II) and Mn(II) ions on S(IV) oxidation could lead to new ideas for the design of SFGD systems.
研究领域:
环境化学
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化学动力学
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海洋化学
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污染控制技术
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脱硫工艺工程
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2022
·
IF 14.224
Tong Liu,Yang Liu,Peng Zhou,Zhaokun Xiong,Heng Zhang,Chuanshu He,Ye Du,Gang Yao,Bo Lai
As one of the most promising advanced oxidation processes , the activation of S(IV) by iron-based materials to produce SO 4 •− has become a hot technology for the degradation of organic pollutants . However, the mechanism of radical chain reactions has not been clearly explored. Herein, we established a novel AOP system based on the combination of zero-valent iron (ZVI) and potassium pyrosulfite (PPS). Combined with the degradation trends of CBZ and the change of DO concentration, the system was proposed to be divided into a slow initiation stage in 5 min and a rapid degradation stage in 5 − 10 min. Through a series of quenching experiments, electron paramagnetic resonance tests and several probe experiments, the mechanisms of two radical chain reactions were proposed between ZVI and PPS: the first one produced O 2 •− and HO • , and the other produced SO 3 •− , SO 5 •− , SO 4 •− and HO • . The two-stage reaction and two radical production paths of the ZVI/PPS system were proposed for the first time, which provided theoretical guidance for the practical application of the ZVI/PPS system. The ZVI/PPS system has been found to have excellent environmental adaptability in the treatment of industrial wastewater .
研究领域:
环境科学
·
化学工程
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产品关联
DOI
高影响因子
CHEMOSPHERE
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2022
·
IF 8.943
Wenkai Liu,Bin Liu,Xin Li
The aim of this study was to investigate the feasibility and fouling mitigation mechanisms of UV/Fe(II) synergistically activated sulfite (S(IV)) (UFS) pretreatment to alleviate membrane fouling caused by HA-enhanced Ca 2+ scaling. After UFS treatment, hydrophobic substances and carboxyl groups structure were destroyed by the in-situ-generated SO•–4, resulted in a significant reduction of hydrophobic substances ratio and carboxyl group concentration. Due to the formation of more electropositive in-situ-generated Fe(III), the complexation between Ca 2+ and carboxyl groups was weakened so that the bulk crystallization size on the membrane surface was greatly reduced. The filter cake enhanced osmotic pressure effect (CEOP) and concentration polarization effect were hence alleviated, as well as the surface roughness . At the microcosmic perspective, as the energy barrier between the membrane and foulants was increased significantly after pretreatment, the anti -foulants adsorption ability of the membrane was enhanced. Correlation analysis showed that the carboxyl concentration and density, HPO ratio, larger particle size (>100 nm) ratio, the Ca 2+ concentration in the scaling layer and energy barrier all had a good correlation with the membrane resistance. This research not only provides an advanced oxidation technology that can effectively alleviate the synergistically-fouling effect of HA and Ca 2+ of nanofiltration process, but also proposes a guidance for the UV/Fe(II) synergistically activated sulfite.
研究领域:
环境科学
·
水处理技术
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膜分离技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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