SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Nuo Cheng,Fu Deng,Jinlong Wang,Longfeng Hu,Jiaxuan Yang,Shu Jiang,Hesong Wang,Xiaofei Ma,Lei Zhao,Guibai Li,Han Zhang,Heng Liang
The membrane electrochemical reactor (MER) achieved synergistic textile wastewater treatment, alkaline solution recovery and magnesium coagulant recycling by the one-time addition of magnesium salt to the anode, solving the problems of reagent wastage and increased wastewater salinity caused by the continuous addition of chemicals in traditional treatments. In this study, the rapid adsorption and precipitation (within 3 min) of DB-86 in the cathode chamber by the magnesium coagulant were stimulated by the hydrophobicity of DB-86, resulting from the relatively dispersed localization of negative charges on the H atoms on the molecule’s surface. The precipitated solids in the cathode effluent were recovered through an ultra-filtration process and recycled to the anode for dissolution. Effective mineralization of dyes was achieved by anode electrolysis, generating large amounts of active chlorine on its surface as an indirect oxidant, resulting in 80.15 % TOC removal after 30 min. Operational stability tests were conducted using both simulated dye wastewater and actual textile wastewater. The decolorization efficiency of the system remained at 99.9 % for simulated dye wastewater and 99.5 % for actual textile wastewater after six cycles of long-term operation. Magnesium hydroxide is re-dissolved at the anode, then passes through the ion exchange membrane into the cathode for recycling. Loss of magnesium ions occurs only at the ultra-filtration surface, achieving recovery efficiencies exceeding 95 % for simulated dye wastewater and 80 % for actual textile wastewater. The MER/Mg system in this study achieved rapid coagulation and mineralization of DB-86, along with efficient recycling of Mg 2+ ions, thus avoiding wastage of chemical sludge and reagents, and reducing chemical consumption and treatment costs.
研究领域:
环境科学
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化学工程
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水处理技术
✓ 已验证
产品关联
DOI
高影响因子
Desalination and Water Treatment
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2024
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IF 1
Chunhua Dai,Chuanyu Deng,Lei Zhang,Liang Wu,Tongwen Xu,Yonghui Wu
ABSTRACT Zwitterionic multisilicon copolymer is prepared from the copolymerization of 2-acrylamide-2-methyl- 1-propanesulfonic acid and γ-methacryloxy propyl trimethoxyl silane, which contain –NH–, –SO 3 H and –Si(OCH 3 ) 3 groups. The copolymer is then taken sol–gel reaction with polyvinyl alcohol to form hybrid membranes. The hybrid membranes are strong acidic and weak basic, which are used in diffusion dialysis (DD) process for alkali recovery. The hybrid membranes are generally homogeneous and compact. The initial decomposition temperature values are in the range of 204°C–210°C and the T d values are in the range of 225°C–231°C. The highest value of tensile strength is 51.8 MPa and the elongation at break (E b ) is in the range of 72.1%–289.7%. The membranes have the water uptake (W R ) of 27.7%–88.3% and cation exchange capacity of 0.90–2.15 mmol g –1 . The DD process shows that the dialysis coefficient of NaOH (U OH ) is in the range of 0.0079–0.0151 m h –1 and the selectivity (S) can reach up to 32.7. The favorable performances are attributed to the combining effect of –OH, –NH– and –SO 3 H groups.
研究领域:
材料科学
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环境工程
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化学工程
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL RESEARCH
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2025
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IF 7.7
Tingting Deng,Xueliang Zhou,Dapeng Liu,Ganwei Zhang,Shusu Shen,Yaoliang Hong
Membrane separation is a promising technology for the treatment of acid/alkali wastewater. However, their poor stability when exposed to corrosive media at elevated temperatures was still a challenge that hindered their wide application. Herein, a robust dual-layer bicomponent membrane consisting of an electrospinning polytetrafluoroethylene (PTFE) skin and a poly(vinylidene fluoride) (PVDF) fiber substrate was facilely fabricated by sequential electrospinning and hot-pressing for acid/alkali recovery via membrane distillation (MD). Benefitting from the low surface energy and chemically inert characteristics of PTFE, the as-prepared membranes showed superhydrophobic characteristics (151.23 ± 2.23°), and strong acid/alkali resistance at elevated temperatures. MD experiments showed that the optimized membranes exhibited a permeate flux of 24.23 ± 0.36 kg·m -2 ·h -1 while maintaining superior flux stability and re-usability. In addition, high retention performance and up to 60 % water recovery were achieved, regardless of whether acid /alkali solutions were used as the feed. These findings indicated that this dual-layer membrane might act as a promising candidate for concentrating acid/alkali solution while generating fresh water via MD.
研究领域:
环境科学
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膜分离技术
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材料科学
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化学工程
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水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
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2019
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IF 3.073
Meng Li,Mengjie Sun,Wenya Liu,Xu Zhang,Cuiming Wu,Yonghui Wu
Composite anion exchanges membranes are prepared by incorporating quaternized graphene oxide (QGO) within poly(vinyl alcohol) (PVA) or the mixture of PVA and quaternized polyethyleneimine (QPEI), followed by cross-linking with formaldehyde. The PVA-QGO series of membranes have low ion exchange capacities (IECs) of 0.10–0.37 mmol/g and low water uptakes ( W R ) of 16.1%–22.0%, leading to high area resistances (>60 Ω cm 2 ). The PVA-QPEI-QGO series of membranes show much lower area resistances of 2.47–6.04 Ω cm 2 , which is ascribed to the improved IECs (0.86–1.37 mmol/g) and W R (46.8%–71.4%). Both series of membranes show higher alkali resistance than commercial membrane AMV. Their weight losses are in the range of 0.5%–8.9% after immersion in 60 °C 2 mol/L NaOH alkaline solution for 32 days, while the value of AMV membrane is 19.2%. When utilized for electrodialysis (ED) application to recover NaOH from NaOH/Na 2 WO 4 mixture, the prepared membranes exhibit high selectivity, as evidenced by the low leakage ratio of Na 2 WO 4 . The leakage ratio of the optimized composite membrane to WO 4 2− is only 5.1%, while the leakage ratio of AMV membrane is up to 61.4%. To explore this reason, the composite membranes are selected for the ED separation of monovalent ions. The separation efficiency ( S ) of the optimized membrane is 83.9%, which is similar to the value of commercial anion selective membrane NEOSEPTA® ACS (88.7%), confirming further the selectivity of the composite membranes.
研究领域:
材料科学
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环境工程
✓ 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）