DESALINATION
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2014
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IF 3.96
Wenqiu Su,Tianjun Li,Xiaping Jiang,Xueming Chen
Membrane-free electrodeionization (MFEDI) has been tested successfully for high purity water production in our previous work. However, in order to prevent the constant backward migration of cationic or anionic ions, to achieve equally effective regeneration for both the cationic and anionic resins, and to get neutral concentrate, the electrodes had to be reversed during regeneration. This not only complicated the regeneration process, but also decreased the water recovery and the electrode lifetime. In this work, we improved the resin layer structure and investigated the regeneration performance of MFEDI without electrode polarity reversal . A total of 30 operational cycles were examined. Effective regeneration was achieved. The effluent conductivity was 0.055–0.060 μS/cm only; the average pH value of the concentrate was 7.2; the water recovery was 90%; and the energy consumption was 0.71 kWh/m 3 water.
研究领域:
环境科学
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水处理技术
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2015
·
IF 3.091
Jiayuan Hu,Zhixing Fang,Xiaping Jiang,Tianjun Li,Xueming Chen
A promising membrane-free electrodeionization (MFEDI) process has been proposed for high purity water (HPW) production in our previous work. However, the employ of a large number of weak-acid resins in MFEDI limits this process for purifying the reverse osmosis (RO) permeate of tap water with a pH value below 6.0. In this work, a MFEDI system filled only with mixed strong-acid and strong-base resins was tested to desalinate the synthetic acidic RO permeate. Results demonstrated that the resins regeneration was achieved mainly by electrically enhancing water dissociation after a high current density was imposed to the resin layer. Both good purification and effective regeneration were achieved. The conductivity of effluent was 0.060–0.062 μS/cm only. The energy consumption fluctuated in the range of 0.35–0.41 kW h/m 3 water and the water recovery reached 93.1%. The mixed concentrate collected during regeneration, with an average conductivity of 145 μS/cm and a pH value of 6.5, could be returned to a pretreatment unit for recovery. No chemical was needed and no wastewater was produced. Repetitive experimental results showed the MFEDI system could work stably.
研究领域:
环境工程
·
化学工程
·
水处理技术
·
电化学
·
可持续水资源管理
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Xuejiao Zhang,Shijun Deng,Huachang Jin,Yang Yu,Shuai Liao,Xueming Chen
Previously, we invented and investigated membrane-free electrodeionization (MFEDI), a novel deionization technique that uses ion exchange resins as the critical material, for the production of high-purity water. However, the functional materials used in MFEDI are common resins that cannot simultaneously achieve effective adsorption, easy electrical regeneration, and good conductivity. For instance, strong acid resin, a cation exchange resin commonly used in MFEDI, cannot be easily electrically regenerated; weak acid resin can be easily regenerated, but has poor conductivity and adsorption properties. There are currently no available resins that can meet all of the requirements of conductivity, adsorption and regeneration properties. In this study, a novel amphoteric resin was prepared and characterised. This amphoteric resin contained much more cationic functional groups than anionic functional groups, behaving as a medium-strength acid resin due to the introduction of anionic functional groups. The prepared amphoteric resin exhibited better purification property than weak acid resin, and could be electrically regenerated more easily than strong acid resin. When the amphoteric resin was coupled with strong base resin and the conductivity of the purified water was kept below 0.10 µs/cm, the water recovery and energy consumption were 74.60% and 0.84 kWh/m 3 water, respectively. By contrast, the energy consumption and water recovery were 40.74% and 2.65 kWh/m 3 water for strong acid resin, and 64.44% and 1.53 kWh/m 3 water for weak acid resin under similar conditions. Clearly, the developed amphoteric resin significantly improves the MFEDI properties.
研究领域:
环境科学
·
水处理
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2022
·
IF 11.211
Xuejiao Zhang,Huachang Jin,Shijun Deng,Fengying Xie,Shuang Li,Xueming Chen
In our previous works, membrane-free electrodeionization (MFEDI), an original deionization technique to produce high-purity water, was invented. However, traditional ion exchange resins , the heart of MFEDI, cannot simultaneously achieve effective adsorption, easy electrical regeneration, and good conductivity. Previously, an amphoteric resin, quaternary ammonium- sulfonic acid resin (QA-SAR), that behaved as medium-strength acid resin, was proposed and applied to produce high-purity water with regeneration performance superior to that of traditional resins. Although the regeneration performance of QA-SAR was better than that of traditional resins, the ion-exchange capacity and conductivity were poor, which further resulted in poor effluent and high regeneration voltage. In view of this, a novel amphoteric resin containing more anionic groups than cationic groups and behaving as medium-strength basic resin, sulfonic acid-quaternary ammonium resin (SA-QAR), was proposed herein. It exhibited better regeneration performance and purification performance than traditional resins and QA-SAR. Under the same conditions, the effluent quality of the MFEDI system filled with SA-QAR remained stable and lower than 0.1 μS/cm, with energy consumption of approximately 0.32 kWh/m 3 water, whereas the effluent quality of the system filled with 550A and the system filled with QA-SAR deteriorated quickly, with energy consumption of approximately 0.36 and 0.43 kWh/m 3 water, respectively.
研究领域:
水处理
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离子交换技术
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电去离子
✓ 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）