Resource recovery from wastewater can be an application niche of microbial desalination cells

Microbial desalination cells (MDCs) have been studied as an emerging technology to accomplish simultaneous wastewater treatment and saline water desalination. A good amount of effort has been invested to understand fundamental problems and develop functional systems of the MDC technology. However, a revisit of MDCs' desalination function reveals that the unique requirements like co-location of wastewater and saline water will greatly limit the application of this technology. In addition, the relatively low desalination rate of MDCs will result in a large reactor size and thus higher capital cost. Because of the need for wastewater (as a substrate for electricity generation), the MDC technology may have a promising niche of application for resource recovery from wastewater. A proper design of MDCs will allow the current-driven separation of ammonia, phosphorus, and volatile fatty acids (VFAs) from wastewater for further recovery. Based on the literature data, we conduct a case study analysis of mass flow for MDC-based resource recovery and demonstrate the potential of this function. Resource recovery can be a new function of interest to MDCs and worth further exploration of its technical and economic feasibility.