Review Metals removal and recovery in bioelectrochemical systems: A review Y.V. Nancharaiah a,b,⇑ , S. Venkata Mohan c , P.N.L. Lens b,d a Biofouling and Biofilm Processes Section of Water and Steam Chemistry Division, Bhabha Atomic Research Centre, Kalpakkam 603102, Tamil Nadu, India b Environmental Engineering and Water Technology Department, UNESCO-IHE Institute for Water Education, P.O. Box 3015, 2601 DA Delft, The Netherlands c Bioengineering and Environmental Centre (BEEC), CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India d Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, Tampere, Finland highlights  Bioelectrochemical systems are promising for recovering metal from waste streams.  Bioelectrochemical removal of metal ions was reviewed and summarized.  Studies should focus on metal recovery from metallurgical waste streams and leachates.  Long term operation of bioelectrochemical systems for metal recovery is needed. graphical abstract Waste water Treated water H + Anode chamber Cathode chamber Organic matter CO2 CO2 Exhaust Electricity harvesting e - Biofilm PEM e - e - Electricity supply e - e - e - Meox Mered Me 0 Meox=Ag + , Au 3+ , Co 3+ , Cr 6+ , Cu 2+ , V 5+ , Se 4+ , U 6+ , Co 2+ , Ni 2+ , Cd 2+ Me 0 =Ag 0 , Au 0 , Cu 0 , Se 0 , Hg 0 , Co 0 , Ni 0 , Cd 0 Metal waste water Treated water Mered=Co 2+ , Cr 3+ , V 4+ ,U 4+ article info Article history: Received 30 April 2015 Received in revised form 11 June 2015 Accepted 12 June 2015 Available online 17 June 2015 Keywords: Bioelectrochemical treatment (BET) Biorecovery Heavy metals Microbial fuel cells Wastewater treatment abstract Metal laden wastes and contamination pose a threat to ecosystem well being and human health. Metal containing waste streams are also a valuable resource for recovery of precious and scarce elements. Although biological methods are inexpensive and effective for treating metal wastewaters and in situ bioremediation of metal(loid) contamination, little progress has been made towards metal(loid) recovery. Bioelectrochemical systems are emerging as a new technology platform for removal and recovery of metal ions from metallurgical wastes, process streams and wastewaters. Biodegradation of organic matter by electroactive biofilms at the anode has been successfully coupled to cathodic reduction of metal ions. Until now, leaching of Co(II) from LiCoO 2 particles, and removal of metal ions i.e. Co(III/II), Cr(VI), Cu(II), Hg(II), Ag(I), Se(IV), and Cd(II) from aqueous solutions has been demonstrated. This article reviews the state of art research of bioelectrochemical systems for removal and recovery of metal(loid) ions and pertaining removal mechanisms. Ó 2015 Elsevier Ltd. All rights reserved. 1. Introduction Availability and supply of raw materials such as metal(loid)s can greatly influence the economy (in terms of exports and job creation) of many countries (Hennebel et al., 2015). Since the reserves of raw materials are finite, unequally distributed in the world and rapidly dwindling due to urbanization, high standard of living and the world population explosion, scarcity of critical raw materials is expected in the coming years. In the case of critical metals, the scarcity is perceived as an increased risk faced by the industry and characterized by the price volatility. To avoid the risk of price volatility and to stockpile raw materials for future genera- tions, there is a need to identify secondary sources and to develop suitable technologies for their recovery. In this context, http://dx.doi.org/10.1016/j.biortech.2015.06.058 0960-8524/Ó 2015 Elsevier Ltd. All rights reserved. ⇑ Corresponding author at: Biofouling and Biofilm Processes Section of Water and Steam Chemistry Division, Bhabha Atomic Research Centre, Kalpakkam 603102, Tamil Nadu, India. E-mail addresses: venkatany@gmail.com, v.yarlagadda@unesco-ihe.org (Y.V. Nancharaiah). Bioresource Technology 195 (2015) 102–114 Contents lists available at ScienceDirect Bioresource Technology journal homepage: www.elsevier.com/locate/biortech