Microbial community dynamics and electricity generation in MFCs inoculated with POME sludges and pure electrogenic culture
Journal
International Journal of Hydrogen Energy
Journal Volume
46
Journal Issue
74
Pages
36903-36916
Date Issued
2021
Author(s)
Abstract
Palm Oil Mill Effluent (POME) requires treatment before disposal due to its high organic matter content. In this study, the electrical performance and wastewater treatment efficiency were evaluated for Microbial Fuel Cells (MFC) treating unsterile POME with chemical oxygen demand (COD) from 200 to 10 000 mg/L. Since the inoculum type is a key factor in MFC performance, three types of sludge (methanogenic sludge (MS), facultative sludge (FS), and dry sludge (DS), obtained from the current POME treatment ponds were evaluated as inoculum. Dry sludge (DS) developed a maximum power output of 3.30 W/m3 by oxidizing 71% out of the COD provided by POME (1000 mg/L). Also, raw POME microbiota contributed to an enrichment of the community in DS inoculum along with the operation, in which Geobacter was the predominant genus reaching a current generation of 247 mA/m2 and a power density of 2.36 W/m3. Conversely, pure electrogenic (Shewanella sp.) inoculation led to a diversification process, resulting in a lower current generation of 52 mA/m2 and a power density of 0.10 W/m3. Consequently, microbial community dynamics revealed that MFC inoculation tends to a microbial equilibrium wherein generation of high current density was achieved by gradual microbial enrichment rather than external electrogenic invasion. ? 2021 Hydrogen Energy Publications LLC
Subjects
Microbial community dynamics
Microbial fuel cell
Palm oil mill effluent
Shewanella
Sludge
Chemical oxygen demand
Dynamics
Effluent treatment
Effluents
Microorganisms
Palm oil
Wastewater disposal
Wastewater treatment
Chemical-oxygen demands
Current generation
Dry sludge
Dynamic generation
Inocula
Palm oil mill effluents
Power densities
Microbial fuel cells
Type
journal article