Hydrogen and electricity production from anaerobic digestion of rice vermicelli wastewater by mixed acidophilic consortia in a microbial fuel cell

Abstract

Industrial wastewater pretreatment through the anaerobic digestion is able to generate both biogas and electricity in microbial fuel cells (MFCs). In this work, hydrogen was produced in MFC combining rice vermicelli wastewater treatment using enriched hydrogen producing consortia. Effects of sludge pretreatment and addition of supplements, mediator (lignin) and glucose were studied to determine the optimum condition for the operation in MFC. The results showed that the pretreatment of sludge inhibited methanogenesis and higher content of hydrogen gas was substantially produced. Adding glucose and lignin was found to facilitate hydrogen production (50.2%). In MFC, pretreated sludge was able to produce more fermentative hydrogen, higher COD removal and solid removal, nevertheless generated electricity was reduced compared with untreated sludge. An increase of amount of granular activated carbon (GAC) used as anode from 700 to 1200 g considerably enhanced hydrogen production from 20.02 to 73.25 % (115 to 926 mL), increased power density from 11.92 to 20.33 mW/m2 (at 750A) and increased COD removal from 45.45 to 57.14%.