Development of a fixed-structured bed anaerobic bioreactor with assisted electron transfer for biogas production and wastewater treatment

Abstract

Anaerobic Digestion (AD) has been widely used for biogas or biofuel generation from waste treatment. Because a low production rate and instability of AD occur frequently, a variety of configurations have been applied to improve the process. A novel Anaerobic Biodigester Fixed Structured Bed (ABFSB) has been used as a technological alternative to packed-bed configuration preventing the accumulation, clogging and channeling effects. Even though its operation is more stable and efficient, still demonstrate limited feasibility and applicability to treat large amounts of organic matter and pollutants. Recent studies showed that application of Microbial Electrolysis Cell (MEC) to AD processes offer an innovative solution to these issues. This approach is based on the insertion of a pair of electrodes (anode and cathode) and the inversion of power to alter AD microbial community, increase kinetics and drive thermodynamically unfavorable reaction that accelerate degradation and bioconversion of a substrate. This can be monitored in real-time by detecting electric signals, which linearly correlate with substrate concentrations. Thus, this study aims to optimize the operational performance of an ABFSB by integrating a microbial electrolysis cell. To determine high bioconversions from a given complex synthetic organic substrate (800 mg CODL-1), different externally applied voltage (0.3, 0.5, 0.8 and 1.0 V), and inoculum sources (raw and pretreated sludge) will be analyzed. Results will provide an insight into the mechanism of bioelectrochemical conversion at each condition and determine which applied voltage improves the AD process on ABFSB. (AU)