(450a) Microbial Desalination Cells for Simultaneous Wastewater Treatment and Water Desalination: Status, Challenges and Perspectives
Microbial desalination cells (MDCs) are a newly emerged technology that takes advantage of microbial metabolism with organic compounds (e.g., organics in wastewater) to generate electrons, which drive salt migration to achieve desalination. An MDC integrates microbial fuel cells (MFCs) and electrodialysis (ED). Compared with an MFC, an MDC contains both cation and anion exchange membranes and has additional compartment for desalination. Unlike ED, an MDC does not require additional voltage or is applied with a small external voltage (less than 1 V) that is not sufficient for water oxidation. The bioenergy-driven desalination in an MDC makes this technology attractive as a low-energy desalination process. However, desalination efficiency in an MDC is generally low; therefore, the potential application of MDC technology is either as pre-treatment of conventional desalination processes or desalination of brackish water. Since the first MDC was reported in 2009, there has been some progress towards MDC development. Our team at Virginia Tech is one of the most active and productive groups in the MDC research. We have investigated membrane fouling, desalination of both brackish water and seawater, system configuration and operation. Especially, we have scaled up the MDC system from bench scale to a transitional scale (~100 L), which represents the largest MDC system worldwide. We have also synergistically link MDCs to osmotic bioelectrochemical systems or forward osmosis to accomplish water reuse and improve desalination performance. In this presentation, we will introduce the current status of MDC research, discuss the challenges in its development, and provide some perspective on its application in wastewater treatment, water desalination, and water reuse.