Development of Bioelectrochemical System for Monitoring the Biodegradation Performance of Activated Sludge

Abstract

In the microbial electrochemical system (MES), the microbial-electrode interactions are often regulated by the metabolic pathway and respiratory activities. To improve the efficiency of MES, there is a need to introduce a microbial community that provides a continuous oxidation of organic substrates with a sustainable current output. Thus, activated sludge was suggested and the rapid evaluation of its biodegradation activity, using cyclic voltammetry, was performed. Stimulation of the metabolic pathway led to the appearance of an oxidation peak current (22 μA/cm(2), at about 750 mV), whereas the electrochemical signals were originated only from the metabolically active microbes. Cell viability, cultivation time, type, and concentration of the degradable organic substrates have been identified as major regulators for the electrocatalytic performance. From two different microbial communities, the generated electrochemical signal of the aerobic activated sludge was more than twofold higher in converting the degradable organic substrates (glucose, acetate, and succinate at 10 g/L) into oxidation current. On the other hand, the secretion of electroactive metabolite(s) in the extracellular matrix was determined as a source of electrochemical signal. Moreover, the mechanism(s) of the microbe-electrode interactions were demonstrated. Therefore, the current bioelectrochemical system could be used as a platform for monitoring the rate of substrate degradation as well as measuring the metabolic pathway activity.

Microbial diversity structure in acetate single chamber microbial fuel cell for electricity generation

“…There are two general techniques of transmitting the electrons to the anode: First way is Mediated Electron Transfer (MET), the use of external redox mediators to wire the electrode biofilm interaction(s) [19], [20]. Second way is a physical adherence between the microorganism and the anode electrode surface surfaces (Direct Electron Transfer, DET) [21], [22]. Therefore, the surface layer of the microorganism has to have a conducive surface (e.g.…”

Biosensing of algal‐photosynthetic productivity using nanostructured bioelectrochemical systems

“…A homemade glass single‐chamber MFC (SMFC; 250 mL total volume, 200 mL working volume) was used in this study . The exposed anode/cathode area was 4 cm 2 .…”

Direct Determination of Bacterial Cell Viability Using Carbon Nanotubes Modified Screen‐printed Electrodes

“…MESs are non‐invasive techniques for the direct detection of extra‐or/and intracellular activities –. In the MESs, biodegradable organic substrates provide the necessary nutrition to living organisms.…”

“…As a result of the microbial‐catalytic oxidation of the degradable organic compounds, electrons are liberated through the electron transport chain (ETC), which are transferred to a molecule other than oxygen, under anaerobic conditions . In the presence of appropriate electrode material(s), accepting the electrons leads to generation of electrical current which is directly proportional to the activity as well as the total number of viable microbial cells (i. e. the metabolically active microbes) –. On the other hand, dormant or dead cells do not have electrochemical activity and thus they are not involved in the microbial electrochemical activities .…”