Using Microbial Desalination Cell to Treat Iraqi Wastewater

Abstract

A Three-chambers MDC was made using three identical cubical plexi-glass sections. Each chamber has an effective volume of 35 cm3. An anion exchange membrane (AEM) was used to separate the anode from the desalination chambers while a cation exchange membrane (CEM) was used to separate the cathode from the desalination chambers. Two graphite sheets were used as anode and cathode electrodes. Biotic experiments have included air-cathode MDC fed with synthetic municipal wastewater, Bio-cathode MDC in which the cathode chamber was inoculated with microalgae as an oxygen sourceand air-cathode MDC was fed with floated oil layer in the anode chamber as an organic source. Maximum power density obtained from the MDC was 121 mW/m2. The corresponding current density was 410 mA/m2. Maximum power density obtained in this study was inconsistencywith that presented in previous studies. Maximum coulombic efficiency and charge efficiency achieved were 9% and 165% respectively. The results of this study confirmed the validity of using MDC technology to treat municipal wastewater as well asoil, desalinate brackish water and generate electric power simultaneously. Moreover, the results revealed the possibility of using mixed culture algae, available in the Iraqi environment, in the cathode chamber as an oxygen source to develop more energy efficient MDC. Further study deals with different system configurations and different operating conditions areneeded