Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
Department of Chemical Engineering, Villanova University, Villanova, PA 19085, USA.
Water Res. 2015 Jun 15;77:13-23. doi: 10.1016/j.watres.2015.03.008. Epub 2015 Mar 20.
Desalination of brackish water can provide freshwater for potable use or non potable applications such as agricultural irrigation. Brackish water desalination is especially attractive to microbial desalination cells (MDCs) because of its low salinity, but this has not been well studied before. Herein, three brackish waters prepared according to the compositions of actual brackish water in three locations in Israel were examined with domestic wastewater as an electron source in a bench-scale MDC. All three brackish waters could be effectively desalinated with simultaneous wastewater treatment. The MDC achieved the highest salt removal rate of 1.2 g L(-1) d(-1) with an initial salinity of 5.9 g L(-1) and a hydraulic retention time (HRT) of 0.8 d. The desalinated brackish water could meet the irrigation standard of both salinity (450 mg L(-1) TDS) and the concentrations of major ionic species, given a sufficient HRT. The MDC also accomplished nearly 70% removal of organic compounds in wastewater with Coulombic efficiency varied between 5 and 10%. A previously developed MDC model was improved for brackish water desalination, and could well predict salinity variation and the concentrations of individual ions. The model also simulated a staged operation mode with improved desalination performance. This integrated experiment and mathematical modeling approach provides an effective method to understand the key factors in brackish water desalination by MDCs towards further system development.
海水淡化可为饮用水或非饮用水应用（如农业灌溉）提供淡水。由于盐度低，海水淡化对微生物脱盐电池（MDC）特别有吸引力，但在此之前，这方面的研究还不够充分。在此，使用家庭废水作为电子源，在实验室规模的 MDC 中对根据以色列三个地点实际海水的组成制备的三种海水进行了研究。所有三种海水都可以通过同时处理废水来有效脱盐。MDC 在初始盐度为 5.9 g/L 和水力停留时间（HRT）为 0.8 d 的情况下，实现了 1.2 g/L/d 的最高盐去除率。对于足够的 HRT，脱盐海水可以满足灌溉标准，即盐分（450 mg/L TDS）和主要离子种类的浓度。MDC 还实现了废水中有机化合物近 70%的去除，库仑效率在 5%至 10%之间变化。之前开发的 MDC 模型已针对海水淡化进行了改进，能够很好地预测盐度变化和单个离子的浓度。该模型还模拟了具有改进脱盐性能的分阶段操作模式。这种集成的实验和数学建模方法为理解 MDC 海水淡化中的关键因素提供了一种有效方法，有助于进一步的系统开发。
