Coupling of anodic biooxidation and cathodic bioelectro-Fenton for enhanced swine wastewater treatment

A novel bioelectrochemical reactor with anodic biooxidation coupled to cathodic bioelectro-Fenton was developed for the enhanced treatment of highly concentrated organic wastewater. Using swine wastewater as a model, the anode–cathode coupled system was demonstrated to be both efficient and energy-saving. Without any external energy supply to the system, BOD5, COD, NH3-N and TOC in the wastewater could be greatly reduced at both 1.1 g COD L−1 d−1 and 4.6 g COD L−1 d−1 of OLR, with the overall removal rates ranging from 62.2% to 95.7%. Simultaneously, electricity was generated at around 3–8 W m−3 of maximum output power density. Based on electron balance calculation, 60–65% of all the electrons produced from anodic biooxidation were consumed in the cathodic bioelectro-Fenton process. This coupled system has a potential for enhanced treatment of high strength wastewater and provides a new way for efficient utilization of the electron generated from biooxidation of organic matters.