Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
Environ Sci Technol. 2010 Dec 15;44(24):9578-83. doi: 10.1021/es1025646. Epub 2010 Nov 15.
A new approach to water desalination is to use exoelectrogenic bacteria to generate electrical power from the biodegradation of organic matter, moving charged ions from a middle chamber between two membranes in a type of microbial fuel cell called a microbial desalination cell. Desalination efficiency using this approach is limited by the voltage produced by the bacteria. Here we examine an alternative strategy based on boosting the voltage produced by the bacteria to achieve hydrogen gas evolution from the cathode using a three-chambered system we refer to as a microbial electrodialysis cell (MEDC). We examined the use of the MEDC process using two different initial NaCl concentrations of 5 g/L and 20 g/L. Conductivity in the desalination chamber was reduced by up to 68 ± 3% in a single fed-batch cycle, with electrical energy efficiencies reaching 231 ± 59%, and maximum hydrogen production rates of 0.16 ± 0.05 m(3) H(2)/m(3) d obtained at an applied voltage of 0.55 V. The advantage of this system compared to a microbial fuel cell approach is that the potentials between the electrodes can be better controlled, and the hydrogen gas that is produced can be used to recover energy to make the desalination process self-sustaining with respect to electrical power requirements.
一种新的海水淡化方法是利用放电子细菌从有机物的生物降解中产生电力，将带电离子从称为微生物脱盐细胞的微生物燃料电池的两个膜之间的中间室中移动。使用这种方法的脱盐效率受到细菌产生的电压的限制。在这里，我们研究了一种替代策略，该策略基于提高细菌产生的电压，以使用我们称为微生物电渗析电池（MEDC）的三室系统从阴极实现氢气的析出。我们使用初始 NaCl 浓度为 5 g/L 和 20 g/L 的两种不同初始 NaCl 浓度来检查 MEDC 过程的使用情况。在单个进料批循环中，脱盐室内的电导率降低了 68 ± 3%，电能效率达到了 231 ± 59%，在施加 0.55 V 的电压时，最大氢气产率达到了 0.16 ± 0.05 m(3) H(2)/m(3) d。与微生物燃料电池方法相比，该系统的优势在于可以更好地控制电极之间的电位，并且产生的氢气可以用于回收能量，以使脱盐过程在电力需求方面实现自给自足。
