Review Wastewater treatment in microbial fuel cells e an overview Veera Gnaneswar Gude Department of Civil & Environmental Engineering, Mississippi State University, Mississippi State, MS 39762, USA article info Article history: Received 28 August 2015 Received in revised form 5 February 2016 Accepted 5 February 2016 Available online xxx Keywords: Microbial fuel cell Bioelectrochemical systems Wastewater Bioenergy Algae Source separation abstract Environmental issues associated with water sanitation are not confined to developing countries alone but are the most basic human and environmental necessities all over the world. Wastewater sources are major causes for environmental pollution in surface and ground water bodies. Current wastewater treatment technologies are not sustainable to meet the ever growing water sanitation needs due to rapid industrialization and population growth, simply because they are energy- and cost-intensive leaving latitude for development of technologies that are energy-conservative or energy-yielding. For the pre- sent and future context, microbial fuel cells technology may present a sustainable and an environ- mentally friendly route to meet the water sanitation needs. Microbial fuel cell based wastewater systems employ bioelectrochemical catalytic activity of microbes to produce electricity from the oxidation of organic, and in some cases inorganic, substrates present in urban sewage, agricultural, dairy, food and industrial wastewaters. This article presents the potential for energy generation and comprehensive wastewater treatment in microbial fuel cells. The article provides an overview of recent literature with two specific aims. First, it provides an overview of current energy needs for wastewater treatment and potential energy recovery options followed by a comprehensive review of the principles of wastewater treatment, substrate utilization (organic removal), recent process developments, nutrient and metal removal capacities in microbial fuel cells. Several issues related to process performance, organic removal capacities and potential environmental impacts were discussed in detail. From the economic and life cycle assessment point of view, although recent developments in power production are encouraging, important discoveries in electrode materials, innovative and integrated process configurations along with experience in pilot scale studies are urgently required to determine the real potential of the mi- crobial fuel cell technology to provide sustainable and energy-positive wastewater treatment. © 2016 Elsevier Ltd. All rights reserved. Contents 1. Introduction ....................................................................................................................... 00 2. Energy consumption and recovery in wastewater treatment ............................................................................. 00 2.1. Energy recovery in wastewater treatment systems .......................................... .................................... 00 2.2. Energy recovery options from wastewater sludge ................................................................................ 00 2.2.1. Anaerobic digestion .................................................................................................. 00 2.2.2. Thermochemical processes ................................................. .......................................... 00 2.2.3. Other energy recovery options ......................................................................................... 00 3. Microbial fuel cells (MFCs) .......................................................................................................... 00 3.1. Advantages of MFCs over other available options ................................................................................. 00 3.2. Principles of waste treatment via MFCs ......................................................................................... 00 3.3. Oxidationereduction reactions (ORR) in MFCs .................................................................................. 00 3.3.1. Oxidation reactions (anode) ............................................................................................ 00 3.3.2. Reduction reactions (cathode) .......................................................................................... 00 4. Organic removal in MFCs ........................................................................................................... 00 4.1. MFCs with synthetic wastewater as substrates .................................................................................. 00 E-mail addresses: gude@cee.msstate.edu, gudevg@gmail.com. Contents lists available at ScienceDirect Journal of Cleaner Production journal homepage: www.elsevier.com/locate/jclepro http://dx.doi.org/10.1016/j.jclepro.2016.02.022 0959-6526/© 2016 Elsevier Ltd. All rights reserved. Journal of Cleaner Production xxx (2016) 1e21 Please cite this article in press as: Gude, V.G., Wastewater treatment in microbial fuel cells e an overview, Journal of Cleaner Production (2016), http://dx.doi.org/10.1016/j.jclepro.2016.02.022