Department of Environmental Engineering, Faculty of Environment, University of Tehran, Tehran, Iran.
J Environ Health Sci Eng. 2014 Feb 17;12(1):48. doi: 10.1186/2052-336X-12-48.
Vulnerability of water resources to nutrients led to progressively stricter standards for wastewater effluents. Modification of the conventional procedures to meet the new standards is inevitable. New technologies should give a priority to nitrogen removal. In this paper, ammonium chloride and urine as nitrogen sources were used to investigate the capacity of a microbial electrolysis cell (MEC) configured by cation exchange membrane (CEM) for electrochemical removal of nitrogen over open-and closed-circuit potentials (OCP and CCP) during biodegradation of organic matter. Results obtained from this study indicated that CEM was permeable to both organic and ammonium nitrogen over OCP. Power substantially mediated ammonium migration from anodic wastewater to the cathode, as well. With a urine rich wastewater in the anode, the maximum rate of ammonium intake into the cathode varied from 34.2 to 40.6 mg/L.h over CCP compared to 10.5-14.9 mg/L.h over OCP. Ammonium separation over CCP was directly related to current. For 1.46-2.12 mmol electron produced, 20.5-29.7 mg-N ammonium was removed. Current also increased cathodic pH up to 12, a desirable pH for changing ammonium ion to ammonia gas. Results emphasized the potential for MEC in control of ammonium through ammonium separation and ammonia volatilization provided that membrane characteristic is considered in their development.
水资源对养分的脆弱性导致了对废水排放更严格的标准。为了满足新标准，对常规方法进行修改是不可避免的。新技术应优先考虑去除氮。本文采用氯化铵和尿液作为氮源，研究了阳离子交换膜（CEM）配置的微生物电解池（MEC）在有机物生物降解过程中在开路和闭路电位（OCP 和 CCP）下电化学去除氮的能力。本研究结果表明，在 OCP 下，CEM 对有机物和铵态氮都具有渗透性。在 OCP 下，电流还极大地促进了氨氮从阳极废水向阴极的迁移。在以尿液为富氮源的阳极中，与 OCP 相比，CCP 下阴极对铵的最大摄取速率从 34.2 到 40.6 mg/L.h 不等。CCP 下的铵分离与电流直接相关。对于 1.46-2.12 mmol 电子产生，去除了 20.5-29.7 mg-N 铵。电流还将阴极 pH 提高到 12，这是将铵离子转化为氨气的理想 pH 值。结果强调了 MEC 通过铵分离和氨挥发来控制铵的潜力，前提是在开发过程中考虑膜特性。
