Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, No.1 Xikang Road, Nanjin, 210098, China; School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China.
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, No.1 Xikang Road, Nanjin, 210098, China.
Chemosphere. 2022 Nov;306:135386. doi: 10.1016/j.chemosphere.2022.135386. Epub 2022 Jun 17.
Microbial desalination cells (MDC) syndicate the advantage of physical separation by using membranes to create conditions required for Bioelectrochemical processes for the treatment of various domestic and industrial wastewater, while simultaneously desalinating saline water and generating bioenergy. However, since the introduction of this technology, heavy metal removal has been a challenge, and membrane fouling has become a major bottleneck limiting the optimum performance and efficiency of this technology. This study incorporated the use of ZIF-8 nanocomposite membrane via phase inversion mechanism in MDC for simultaneous heavy metal removal and membrane biofouling prevention. The study was conducted in two MDC systems; MDC-Control (without the ZIF-8 nanocomposite membrane) and MDC with ZIF-8 nanocomposite membrane. The results from the experiment shown that maximum removal efficiency of 85.7%, 84.3%, 84.0%, and 90.61% was obtained for Cu, Zn, Pb and Cd respectively in MDC-ZIF-8, while MDC control showed 54.17%, 59.71%, 51.94%, and 54.17%. The results were well fitted to the Langmuir adsorption isotherm with correlation coefficients (R) > 0.99 in all cases for MDC-ZIF-8. A maximum adsorption capacity (Q) of 292 mg g was attained for all four metal ions in MDC-ZIF-8. Besides, after 38 days of continuous operation with two complete desalination for both systems, the SEM-EDS characterization analysis, polarization characteristics, and power generation revealed antifouling characteristics of ZIF-8 nanocomposite membrane incorporated in MDC. The integration of the ZIF-8 nanocomposite membrane proved to be simultaneously efficient in biofouling prevention and heavy metal removal without jeopardizing the system's ability for wastewater treatment, bioelectricity generation, and desalination processes.
微生物脱盐电池（MDC）结合了膜的物理分离优势，为各种生活污水和工业废水的生物电化学处理创造了所需的条件，同时淡化盐水并产生生物能。然而，自这项技术问世以来，重金属去除一直是一个挑战，而膜污染已成为限制该技术最佳性能和效率的主要瓶颈。本研究通过相转化机制在 MDC 中引入 ZIF-8 纳米复合材料膜，以实现同时去除重金属和防止膜生物污染。该研究在两个 MDC 系统中进行；MDC-Control（没有 ZIF-8 纳米复合材料膜）和具有 ZIF-8 纳米复合材料膜的 MDC。实验结果表明，在 MDC-ZIF-8 中，Cu、Zn、Pb 和 Cd 的最大去除效率分别为 85.7%、84.3%、84.0%和 90.61%，而 MDC 控制则分别为 54.17%、59.71%、51.94%和 54.17%。在所有情况下，MDC-ZIF-8 的结果都很好地符合 Langmuir 吸附等温线，相关系数（R）>0.99。在 MDC-ZIF-8 中，所有四种金属离子的最大吸附容量（Q）均为 292mg g。此外，在两个系统都进行了 38 天的连续运行和两次完整的脱盐后，通过 SEM-EDS 特征分析、极化特性和发电，揭示了 ZIF-8 纳米复合材料膜在 MDC 中的抗污染特性。事实证明，在不影响系统处理废水、发电和脱盐能力的情况下，将 ZIF-8 纳米复合材料膜集成到 MDC 中具有同时高效的防污和重金属去除效果。
