CHEMICAL ENGINEERING JOURNAL
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2018
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IF 6.735
Shaolong Yang,Zhitao Han,Xinxiang Pan,Bojun Liu,Dongsheng Zhao
UV/chlorine has attracted much attention in flue gas and water treatment fields in recent years. However, only a few studies highlighted gas pollutants removal performance of UV/chlorine method in real water. In this study, nitrogen oxide (NO x ) removal using UV-irradiated electrolyzed seawater (UV/electrolyzed seawater) was explored under simulated seawater environment in a semi-batch photochemical reactor. Comparison experiments between UV/H 2 O 2 and UV/chlorine in both freshwater and seawater systems were performed. Results showed that NO removal efficiency in UV/chlorine freshwater system was higher than those in UV/chlorine seawater system, due to radical scavenging effects of water matrices in seawater. Several strong reactive radicals (e.g., OH, Cl, OCl, ClOH − ) yielded from UV/chlorine system were considered to contribute to NO x removal, among which the role of OH radical was confirmed by radical-trapping experiments. The alkalinity of the seawater adversely impacted contributions of these reactive radicals to NO x removal, which caused a sharp drop in NO x removal efficiencies. Comparatively, the chloride ion in seawater had slight influences on NO x removal efficiencies of UV/electrolyzed seawater. Then, optimization of NO x removal efficiencies against three key variables (active chlorine concentration, UV irradiation dose, and initial pH) was investigated in simulated seawater using Design Expert Software. A regression model of NO x removal efficiency was obtained with satisfactory accuracy. Results indicated that active chlorine concentration and UV irradiation dose significantly influenced NO x removal efficiencies, compared with pH effects. Furthermore, NO x removal mechanisms involved in reactive radicals were discussed for UV/electrolyzed seawater method. Due to pH-dependent characteristics of both active chlorine species and carbonate species in electrolyzed seawater, NO x removal pathways by UV/electrolyzed seawater were different as the environment changed from acid to alkalinity.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
WATER RESEARCH
·
2022
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IF 13.4
Haolin Xu,Rundong Chen,Sheng Liang,Zhenchao Lei,Wenxiao Zheng,Zhang Yan,Jianxin Cao,Chaohai Wei,Chunhua Feng
The formation of chlorinated byproducts represents a significant threat to the quality of the effluent treated using electrochemical advanced oxidation processes (EAOPs), thus spurring investigation into alleviating their production. This study presents a new strategy to minimize the release of chlorinated intermediates during the electrochemical oxidation of Ni-EDTA by establishing a dual mixed metal oxide (MMO)/Fe anode system. The results indicate that the dual-anode system achieved a substantially higher rate (0.141 min − 1 ) of Ni-EDTA destruction and accordingly allowed a more pronounced removal of aqueous Ni (from 39.85 to 0.63 mg L − 1 ) after alkaline precipitation, compared with its single MMO anode (0.017 min − 1 of Ni-EDTA removal, with 14.38 mg L − 1 Ni remaining) and single Fe anode (insignificant Ni-EDTA removal, with 38.37 mg L − 1 Ni remaining) counterparts. Compared to reactive chlorine species (RCS) produced from the single MMO anode system, Fe(IV) was in situ generated from the dual-anode system and was predominantly responsible for the attenuation of chlorinated byproducts and thus the decrease in the acute toxicity of the treated solution (evaluated using luminescent bacteria). The Fe(IV)-dominated dual-anode system also exhibited superior performance in removing multiple pollutants (including organic ligands, Ni, and phosphite) in the real electroless plating effluent. The findings suggest that the strategy for Fe(II) transition to Fe(IV) by active chlorine paves a new avenue for yielding less chlorinated products with lower toxicity when EAOPs are used to treat chloride-containing organic wastewater.
研究领域:
环境科学
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电化学工程
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2019
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IF 8.355
Chen-Xuan Li,Chang-Bin Chen,Yun-Jie Wang,Xian-Zhong Fu,Shuo Cui,Jia-Yuan Lu,Jie Li,Hou-Qi Liu,Wen-Wei Li,Tai-Chu Lau
The formation of halogenated disinfection byproducts (DBPs) during organic pollutants degradation in advanced oxidation processes (AOPs) has raised growing concerns globally. However, the detailed roles of chlorine ions (Cl − ) in pollutant degradation by peroxymonosulfate (PMS) alone remain controversial so far. Here, we shed light on the PMS-Cl − -phenol interactions and revealed a previously overlooked pH-dependent phenol transformation pathway. At acidic pH, Cl − significantly accelerated the phenol removal. The Cl − -PMS reaction resulted in abundant reactive chlorine species, which attacked phenol to form 4-chlorophenol and 2, 4-dichlorophenol as the main transformation products. In contrast, the impact of Cl − became negligible at alkaline pH. Raising the pH severely suppressed the phenol chlorination and significantly stimulated generation of singlet oxygen ( 1 O 2 ) for degradation of phenol and the minor formed chlorophenols. The 1 O 2 was resulted from a combined effect of PMS self-decomposition and PMS-benzoquinone interaction at alkaline pH. Our results imply a previously-underestimated impact of Cl − on phenolic compounds degradation in PMS-based AOPs and underscore a potential risk of chlorinated DBPs formation under environmental conditions.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
CELLULOSE
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2019
·Vol. 26
·期 9
·5621-5633
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IF 3.917
Zhang Shengli,Kai Chengcheng,Liu Bofang,Zhang Silue,Wei Wei,Xu Xiaoling,Zhou Zuowan
Abstract Polyethylenimine (PEI), a type of water-soluble chain polymer containing a great number of primary, secondary and tertiary amine groups in the molecule, was used as an N-halamine precursor. It was grafted onto dialdehyde cellulose membrane (DCM) followed by chlorination to prepare a novel N-halamine antibacterial cellulose membrane (Cl–PEI–DCM). The appropriate conditions affecting the aldehyde content of DCM and the active chlorine (Cl + ) content of Cl–PEI–DCM were systematically studied at oxidation, grafting and chlorination stages, respectively. The structure and properties of the samples were investigated by SEM, ATR–FTIR, XRD, XPS, light transmittance measurements and tensile tests. The stability and rechargeability of the Cl–PEI–DCM were evaluated, and its antibacterial activity was tested against S. aureus and E. coli . Results showed that the Cl + content of the chlorinated samples was strongly dependent on the aldehyde content of DCM and PEI concentration. Under the optimum testing condition, the Cl + content of the Cl–PEI–DCM reached 1.30 wt%. The hydroxyl groups on the cellulose membrane were changed to aldehyde groups and the successful introduction of PEI and N–Cl bond were confirmed. The 1.30 wt% Cl–PEI–DCM exhibited high antibacterial activity against both S. aureus and E. coli , which can completely inactivate two bacterial pathogens within 5 min even after 15 days of storage. Moreover, the Cl–PEI–DCM membrane displayed good stability, rechargeability, transparency and high mechanical strength. These results demonstrated that the Cl–PEI–DCM can be considered as a visualized wound dressing material or antibacterial shoe insole. Graphical abstract
研究领域:
材料科学
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生物学
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医学
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DOI
高影响因子
ACS ES&T Water
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2022
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IF 0
Nan Chen,Juzhuan Ruan,Sen Lu,Zhen Sun,Guan Zhang
Indirect electrocatalytic (EC) oxidation of ammonia into harmless N2 based on in situ generated reactive chlorine species from chlorinated aqueous streams has been considered as an effective technique for ammonia abatement from water/wastewater. However, the precise oxidation mechanism and contribution of reactive species to the ammonia oxidation are still under debate and deserved to be specifically investigated. In order to enhance mass transfer efficiency, this work systematically investigated and optimized a three-dimensional EC (3D-EC) system, which exhibits about two times higher ammonia oxidation rate compared to a two-dimensional EC system. The polarization characters of particle electrodes have been analyzed to correlate with the enhanced generation of ·OH and ClO· radicals under biased conditions, and the role of each oxidative species was specifically quantified. In the enlarged scale study, water flow-by mode was tested with varying experimental parameters including flow rate, hydraulic residence time, and secondary oxidation. Furthermore, the performance of the 3D-EC system for the treatment of six types of practical wastewater with different levels of ammonia and organics was evaluated. This study provides mechanistic insight on the indirect 3D-EC oxidation of ammonia and its potential application on ammonia wastewater treatment.
研究领域:
环境科学
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化学工程
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DOI
CHEMOSPHERE
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2022
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IF 8.943
Sen Lu,Xuechuan Li,Yunkai Liao,Zhenghua Zhang,Haijian Luo,Guan Zhang
Photoelectrocatalytic (PEC) process combining the merits of photocatalysis and electrocatalysis is considered as a promising ammonia oxidation technology for water treatment . However, some key issues, such as the limited in situ generation of oxidants on photoanode, slow mass transfer problem and generation of nitrate/nitrite by–products hinder the further application of PEC process in the treatment of ammonia pollutant. In this study, the graphite felt (GF) cathodes modified by different transition metals (Ni, Fe, Mn, Co, Cu) were screened by physicochemical and photoelectrochemical characterizations. The results show that the Ni–GF cathode with more Ni 0 uniformly distributed on the GF surface had the best electrocatalytic activity to generate H 2 O 2 . The PEC system composed of 10.0 wt% Ni–GF cathode and optimized titania nanotubes (TNTs) photoanode selectively converted about 96.1% ammonia to N 2 within 90 min. Compared with the single TNTs photoanode system, the ammonia oxidation reaction rate constant of the synergistic PEC oxidation system was increased by about two times, which demonstrated the role of the oxidants simultaneously generated on both anode and cathode. The in situ generated reactive oxygen-based oxidants and chlorine-based oxidants interacted together, and ClO• acted a leading role in the ammonia oxidation which were confirmed by quenching and probe experiments. In addition, the contributions of •OH and ClO• were significantly improved in the synergistic PEC oxidation system, compared with the single TNTs photoanode system. Furthermore, the nitrate by–products generated by the ammonia oxidation were further reduced on the Ni–GF cathode. The large amount of active chlorine and active oxygen generated on the electrode diffused into the bulk, effectively overcoming the mass transfer limitation of direct oxidation. Therefore, the developed TNTs photoanode/Ni-GF cathode system can continuously and efficiently convert ammonia to N 2 without the formation of nitrate/nitrite by–products.
研究领域:
环境科学
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水处理技术
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2025
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IF 9
Zhenhui Song,Tianyu Gao,Huifeng Lu,Qi Zhang,Jingyu Liu,Tingting Kang,Xing Wu,Fubing Yao,Xiaobo Min,Chong-Jian Tang
Electro-oxidation (EO) represents a promising and efficient technology for the disposal of humic acid (HA), leveraging the generation of radicals to degrade pollutants, ultimately achieving their removal or even complete mineralization. However, the detailed mechanistic profiling of the interaction between radical species (e.g. ·OH, active chlorine) and HA in the overall degradation remains significantly unclear, resulting in challenges in tuning and optimizing the treatment of HA-containing wastewater. Herein, a flow-through EO system using a Ti 4 O 7 reactive electrochemical membrane (REM) as a model electrode was constructed to investigate the degradation mechanisms of HA under ·OH or active chlorine. Under optimal conditions (HA 100 mg L −1 , current density 30 mA cm −2 , pH 7), active chlorine achieved a higher HA oxidation efficiency (76.59 %) compared to ·OH (56.60 %) at 1 h, the HA mineralization efficiency of former (53.03 %) over 3 h was lower than that of latter (67.41 %). Meanwhile, multiple techniques (UV–Vis, FTIR, etc.) revealed that ·OH degraded HA’s macromolecular polycyclic structures into aliphatic products, while active chlorine produced mainly small molecular chlorinated aromatics. Furthermore, LC-MS analysis showed that hydroxylation by ·OH is crucial for promoting ring-opening reactions of aromatic compounds, while chlorination by active chlorine proves less effective for this purpose. Adjusting the electrolyte in EO controlled reactive species generation, allowing regulation of HA degradation rates or product distribution, making EO suitable as a pretreatment or advanced treatment in other processes. This work paves a new avenue for the rational design and construction of subprocesses aimed at HA-containing wastewater treatment.
研究领域:
环境科学
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电化学工程
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污染控制
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2017
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IF 6.216
Yue Song,Long Cang,Guodong Fang,Syed Tahir Ata-Ul-Karim,Hongting Xu,Dongmei Zhou
Electrokinetic in situ chemical oxidation (EK-ISCO) is an innovative and effective method for removing petroleum contaminants from soil. However, the high cost of exogenous oxidants is one of the main drawbacks of this technology. In this research, a new approach for the electrokinetic (EK) delivery anodic in situ generation of an oxidant was designed with the aim of solving this problem. Six EK experiments lasting 15 d with different electrolytes (NaCl or NaNO 3 ) and different voltage potentials were performed in order to evaluate the feasibility of this approach. It was found that active chlorine was produced by a dimensionally stable anode and a NaCl solution, and can contribute to remediate sand spiked with diesel fuel (10 g/kg) during EK-ISCO. The obtained results showed that an increase in NaCl electrolyte concentration (from 10 to 40 g/L) increases the maximum concentration of active chlorine in the aqueous sand matrix (from 12.5 to 30 mmol/L). The diesel removal efficiencies were increased from 33% to 44% for 1 V/cm and from 43% to 67% for 2 V/cm, respectively, by using 20 g/L NaCl compared to using 20 g/L NaNO 3 . Vial tests also confirmed that the anodic in situ generated active chlorine in the electrolyte solution had the effect of oxidizing alkanes of diesel. The products had a higher solubility due to the inclusion of polar functional groups. Under optimal conditions, the energy consumption for removing 1% of contaminants was approximately 2 k Wh/ton. Consequently, the EK delivery of anodic in situ generated active chlorine can be considered as a new cost-effective method for removing organic contaminants from porous media.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
Journal of Cleaner Production
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2020
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IF 7.246
Lidong Yu,Xihuai Qiang,Lu Cui,Bo Chen,Xinke Wang,Xiaohui Wu
In this research, a syntan containing active chlorine groups (SACG) was synthesized by the condensation of phenol sulfonic acid condensation product (PSAC) and cyanuric chloride (TCT). The structure and composition of as-received syntans were characterized by Fourier transform infrared spectrometer (FT-IR), nuclear magnetic resonance spectroscopy ( 1 H-NMR), and gel permeation chromatography (GPC). The thermal properties and morphology of the tanned leather were analyzed using thermogravimetric analysis (TGA) and scanning electron microscope (SEM). The results indicated that the multi-point active chlorine groups in syntans had an excellent cross-linking effect on collagen fibers, which increased the shrinkage temperature of leather to 81.6 °C. The tensile strength , the tearing strength, and the thickening rate of the tanned leather were 14.26 MPa, 42.56 N/mm, and 78.3%, respectively. The tanned leather exhibited flat and fine grain. The collagen fibers showed uniform dispersion. Besides, the SACG had remarkable environmental benefits compared with the traditional chrome tanning system by significantly reducing the content of chemical oxygen demand (COD), total solids (TS), dissolved solids (DS), suspended solids (SS), chloride, and total chromium analyses (T Cr ) in tannery wastewater and thus could be applied to non-pickling tanning system. Moreover, the SACG tanning technology is a promoting chrome-free tanning technology because of the facile, cost-effective, and environment-friendly performance, suggesting that this technology has great potential to be widely applied in leather manufacturing.
研究领域:
化学
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皮革科学与工程
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环境科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhaofen Xu,Lingfang Tang,Yuanyi Zhou,Gang Lu,Haojie Dong,Mingshan Zhu
Utilizing the immanent salt (Cl – ) in wastewater to generate reactive chlorine species (RCS) satisfies the future needs for sustainable, on-demand, and decentralized ammonia nitrogen (NH 4 + -N) removal. The microstructural evolution of bismuth oxychloride (BiOCl) photocatalyst under irradiation benefits for overcoming the competition between Cl – and H 2 O oxidation and achieving high N 2 selectivity. Herein, internal electric field (IEF) engineering by carbon doping is applied to promote photocatalytic RCS generation rate over BiOCl. The carbon dopant not only enhances the IEF intensity of BiOCl by a factor of 2.1 times for carrier dynamics promotion, but also improves Cl – oxidation against H 2 O oxidation. An RCS production rate of 0.23 mg/L min −1 is realized over carbon-doped BiOCl (C-BiOCl) through the accelerated interaction between lattice and environmental Cl – , which is twice that of the undoped BiOCl (0.11 mg/L min −1 ). The relation between IEF intensity and RCS generation rate over C-BiOCl manifests a correlation coefficient of 0.96. Effective NH 4 + -N degradation with N 2 selectivity of >99% is validated. The system is competent in dealing with saline NH 4 + -N wastewater with a wide range of NH 4 + -N (20∼200 mg N/L) and NaCl (6∼10 g/L) concentrations. In the treatment of realistic landfill leachate (884 mg N/L NH 4 + -N), C-BiOCl displays a photocatalytic NH 4 + -N removal efficiency of up to 95.6% while maintaining the NO 2 − -N (∼2 mg N/L) and NO 3 − -N (∼40 mg N/L) levels. This system provided an interesting and innovative idea for wastewater self-purification.
研究领域:
环境科学
·
废水处理
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产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2025
·
IF 4.1
Asim Khan,Xinwan Zhang,Kun Wang,Waqas Ahmed,Sajid Ullah,Muhammad Umair Mushtaq,Huawei Hu,Zhihao Lu,Daqing Jia,Lehua Zhang
The application of electro-oxidation (EO) technology in organic dyes is restricted by the drawbacks, such as the expensive electrode materials, high energy consumption, and narrow pH applied range. Herein, a natural manganese sand (NMS)-catalyzed in situ electro-generated active chlorine (e.g., HClO) system was proposed to remove methyl orange (MO). The results show that MO can be efficiently removed by the NMS/EO system over a wide pH range (pH 3–12). Radicals (e.g., HO • , Cl • ) and non-radical active species (e.g., 1 O 2 , Mn 4+ ) are involved in the removal of MO by the NMS/EO system. The effects of important parameters, including the initial solution pH, NMS dosage, current density, electrolyte type, and electrode space, on MO degradation by the NMS/EO system were investigated. The kinetic model of MO removal confirmed that the degradation rate of MO was mainly affected by the dosage of NMS compared with the NaCl concentration. Moreover, the NMS/EO system exhibited a significant reduction in energy consumption for MO removal. This work provides new insights into the degradation of organic dyes by NMS-catalyzed in situ electrogenerated active chlorine.
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
Journal of Water Process Engineering
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2024
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IF 6.3
Ruotong Xu,Xiuneng Zhu,Keshu Sheng,Yulin Tang,Yongji Zhang
The presence of Viable but nonculturable (VBNC) bacteria in drinking water distribution systems(DWDS)which can recover and regain pathogenicity under certain conditions, leads to a serious underestimation of the number of microorganisms in the water and consequently microbiological risks. This study investigated E. coli's biofilm integrity and metabolic activity post‑chlorine disinfection and during resuscitation in a Circulating-flow Dynamic biofilm Contactor (CDC) reactor. Chlorine rapidly induced the VBNC state, with concentrations ≥0.3 mg/L causing all respiratory-active bacteria to transition. Higher chlorine levels damaged cell biofilms, reducing intact cell counts by 95 % and depleting ATP. VBNC bacteria in biofilms quickly regained culturability, utilizing available nutrients and ATP. Within 1–4 days, culturable bacteria in the biofilm increased from 2.29 to 4.95 log CFU/mL, significantly faster than in water. This growth corresponded with rising ATP levels, though slower than in aqueous environments. Signaling molecules (C6, C8, C12, C14) regulated gene expression during resuscitation, aiding bacterial recovery and proliferation. Chlorine disinfection disrupted intercellular communication, altering VBNC bacteria's physiological and metabolic characteristics. These findings highlight the complex dynamics of VBNC bacteria in water systems, their resuscitation potential, and the importance of biofilms in bacterial recovery, emphasizing the need for comprehensive water treatment strategies.
研究领域:
微生物学
·
环境卫生学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）