Tuning Geobacter sulfurreducens biofilm with conjugated polyelectrolyte for increased performance in bioelectrochemical system.

Bioelectrochemical systems (BESs) are emerging as a platform technology with great application potentials such as wastewater remediation and power generation. Materials for electrode/microorganism modification are being examined in order to improve the current production in BESs. Herein, we report that the current production increased almost one fold in single-chamber BES reactors, by adding a conjugated polyelectrolyte (CPE-K) in the growth medium to co-form the anodic biofilm with Geobacter sulfurreducens cells.

COD removal characteristics in air-cathode microbial fuel cells.

Exoelectrogenic microorganisms in microbial fuel cells (MFCs) compete with other microorganisms for substrate. In order to understand how this affects removal rates, current generation, and coulombic efficiencies (CEs), substrate removal rates were compared in MFCs fed a single, readily biodegradable compound (acetate) or domestic wastewater (WW). Removal rates based on initial test conditions fit first-order kinetics, but rate constants varied with circuit resistance.

High current densities enable exoelectrogens to outcompete aerobic heterotrophs for substrate.

In mixed-culture microbial fuel cells (MFCs), exoelectrogens and other microorganisms compete for substrate. It has previously been assumed that substrate losses to other terminal electron acceptors over a fed-batch cycle, such as dissolved oxygen, are constant. However, a constant rate of substrate loss would only explain small increases in coulombic efficiencies (CEs, the fraction of substrate recovered as electrical current) with shorter cycle times, but not the large increases in CE that are usually observed with higher current densities and reduced cycle times.

A two-stage microbial fuel cell and anaerobic fluidized bed membrane bioreactor (MFC-AFMBR) system for effective domestic wastewater treatment.

Microbial fuel cells (MFCs) are a promising technology for energy-efficient domestic wastewater treatment, but the effluent quality has typically not been sufficient for discharge without further treatment. A two-stage laboratory-scale combined treatment process, consisting of microbial fuel cells and an anaerobic fluidized bed membrane bioreactor (MFC-AFMBR), was examined here to produce high quality effluent with minimal energy demands. The combined system was operated continuously for 50 days at room temperature (∼25 °C) with domestic wastewater having a total chemical oxygen demand (tCOD) of 210 ± 11 mg/L.

Treatability studies on different refinery wastewater samples using high-throughput microbial electrolysis cells (MECs).

High-throughput microbial electrolysis cells (MECs) were used to perform treatability studies on many different refinery wastewater samples all having appreciably different characteristics, which resulted in large differences in current generation. A de-oiled refinery wastewater sample from one site (DOW1) produced the best results, with 2.1±0.

Electricity generation from fermented primary sludge using single-chamber air-cathode microbial fuel cells.

Single-chamber air-cathode microbial fuel cells (MFCs) were used to generate electricity from fermented primary sludge. Fermentation (30 °C, 9 days) decreased total suspended solids (26.1-16.

Microbial community structure in an integrated A/O reactor treating diluted livestock wastewater during start-up period.

In order to investigate the correlation between reactor performance and the microorganisms, an integrated NO reactor was operated for 72 days to treat diluted livestock wastewater. Chemical oxygen demand (COD) removal efficiency increased from 79% to 94%, with total nitrogen (TN) removal efficiency from 37% to 50% (HRT 7.4 br) when the influent COD and TN were ca.

Monitoring microbial community structure and succession of an A/O SBR during start-up period using PCR-DGGE.

Polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) protocol was employed for revealing microbial community structure and succession in a sequential anaerobic and aerobic reactor performing enhanced biological phosphorus removal (EBPR) during start-up period. High phosphorus removal was achieved after 15 d. On day 30, phosphorus removal efficiency reached to 83.