Distillery Vinasse (Spentwash) Treatment using Microbial Fuel Cell followed by Rotating Biological Contactor Pradeep N V 1 , Hampannavar U S 2 , Anupama 3 , Vijay S Kumbar 4 , Sneha M K 5 1 Asst. Professor, Dept. of Biotechnology, Ballari Institute of Technology and Management, Bellary, India. Email: nagamallivpradeep@gmail.com 2 Principal and Professor, Angadi Institute of Technology and Management, Belgaum, India. Email: udayhamp@gmail.com 3 Asst. Professor, Dept. of Biotechnology, Ballari Institute of Technology and Management, Bellary, India. Email: akkushekhar@gmail.com 4 Asst. Professor, Dept. of Civil Engineering, Angadi Institute of Technology and Management, Belgaum, India. Email: nagamallivpradeep@gmail.com 5. Asst. Professor, Dept. of Civil Engineering, Adichunchanagiri Institute of Technology, Chikmagalur, India. Email:snehamatad@gamil.com Keywords: Bioelectricity, chemical oxygen demand (COD), Vinasse (Spentwash), air cathode microbial fuel cell (MFC), rotating biological contactor (RBC). Abstract: Distillery spent wash was treated in Microbial Fuel Cell (MFC) and further treatment of optimum effluent was carried out in Rotating Biological Contactor (RBC) at ambient room temperature which varied between 27-32 o C. In the present study single chamber air cathode MFC was used for distillery spent wash treatment and generation of electricity and the optimum effluent from single chamber MFC was treated in RBC. Varied feed concentrations were loaded to single chamber MFC. Single chamber MFC was efficient in power generation and found to be producing maximum current of 0.84 mA and power density of 41.8 mW/m 2 at the feed concentration of 6100 mg COD/L. MFC attained the maximum of 61% COD, 46% total solids (TS) and 48% dissolved solids (DS) removal efficiencies. The performance of single chambered MFC deteriorated at the feed concentration of 9100 mg/L. MFC being anaerobic in nature, it requires further treatment in aerobic processes. The optimal effluent of single chamber MFC i.e., 6100 mg COD/L was given as feed to Rotating Biological Contactor (RBC) and obtained 83% COD, 50% TS and 50% DS removal efficiencies after three days of treatment in RBC. 1. Introduction: Wastes released from many industries are of concern to environment when released untreated. Organic wastes are the major part of effluent generated in many industries. Handling of wastes, treatment and disposal are the major challenges to such industries. A number of clean up technologies have been put into practice and novel bioremediation approaches for treatment of distillery spent wash are being worked out [1]. Harvesting products from wastewater in order to make the process more economical and sustainable is the next frontier in wastewater treatment [2]. Microbial fuel cells (MFC) are unique devices that can utilize microorganisms as catalysts for converting chemical energy directly into electricity, representing a promising technology for simultaneous energy production and wastewater treatment [3, 4]. In MFC electrons generated in anode cell reach the cathode and combine with protons that diffuse from anode through the membrane or agar salt bridge [5, 6]. Using an air cathode MFC can eliminate the need for aeration, and therefore much of the existing energy demands, while producing energy. The abundant electron acceptors i.e., oxygen availability in air is the reason for the higher current generation. In addition, the low cell yields of anaerobic processes, such as MFCs, will produce less waste biomass than aerobic based processes [7]. MFCs operated using mixed microbial cultures currently achieve substantially greater power densities than those with pure cultures [5]. MFCs have been used to treat various kinds of wastewater such as domestic sewage [8, 9], brewery [10, 11], distillery [12], sugar [13], paper and pulp [14] (Huang and Logan, 2008), rice mill [15], swine wastewater [16] and phenolic wastewater [17]. MFCs have some disadvantages, including the high costs of materials (platinum-catalyst and proton exchange membrane), the low efficiency of organic treatment, among others [18].