Energy generation in a Microbial Fuel Cell using anaerobic sludge from a wastewater treatment plant

Abstract

In microbial fuel cells (MFCs), the oxidation of organic compounds catalyzed by microorganisms (anode) generates electricity via electron transfer to an external circuit that acts as an electron acceptor (cathode). Microbial fuel cells differ in terms of the microorganisms employed and the nature of the oxidized organic compound. In this study, a consortium of anaerobic microorganisms helped to treat the secondary sludge obtained from a sewage treatment plant.The microorganisms were grown in a 250 mL bioreactor containing a carbon cloth. The reactor was fed with media containing acetate (as the carbon source) for 48 days. Concomitantly, the electrochemical data were measured with the aid of a digital multimeter and data acquisition system. At the beginning of the MFC operation, power density was low, probably due to slow microorganism growth and adhesion. The power density increased from the 15 th day of operation, reaching a value of 13.5 μW cm -2 after ca. 24 days of operation, and remained stable until the end of the process. Compared with data in the literature, this power density value is promising; improvements in the MFC design and operation could increase this value even further. The system investigated herein employed excess sludge as a biocatalyst in an MFC. This opens up the possibility of using organic acids and/or carbohydrate-rich effluents to feed MFCs, and thereby provide simultaneous effluent treatment and energy generation.

Sludge selection on the performance of sediment microbial fuel cells

“…The reasons for this great difference may be because of the presence of alternative electron acceptors (eg, O 2 , NO 3 _ , and SO 4 2_ ) in the WAS. They may induce a competition for electron donors with the anode and eventually decrease the electron transfer efficiency . Overall results showed that the sludge SMFCs were better than the control MFC in power generation.…”

“…They may induce a competition for electron donors with the anode and eventually decrease the electron transfer efficiency. 13 Overall results showed that the sludge SMFCs were better than the control MFC in power generation.…”

Electrochemical Oxidation of Glycine with Bimetallic Nickel−Manganese Oxide Catalysts

“…However, like other organic pollutants that exist in wastewater, glycine may be oxidized by electrogenic anodic bacteria . Nevertheless, abiotic oxidation of amino acids and proteins requires large overpotentials and has low specificity . Consequently, efforts are required to develop electrocatalyst which can reduce large overpotential below 1.5 V vs. RHE and improve the faradic efficiency as well as fast electron transfer for electrooxidation of glycine …”

“…[8,9] Nevertheless, abiotic oxidation of amino acids and proteins requires large overpotentials and has low specificity. [10] Consequently, efforts are required to develop electrocatalyst which can reduce large overpotential below 1.5 V vs. RHE and improve the faradic efficiency as well as fast electron transfer for electrooxidation of glycine. [11] Electrooxidation of amino acids was first studied by Horanyi and Rizmayer at the gold surface .…”

The use of urban sewage sludge as a substrate in a microbial fuel cell

“…Therefore, the search for ways to use sewage sludge in the technological scheme of sewage treatment plants is an important task. It is assumed that the use of microbial fuel cells (MFC) will not only eliminate sludge, but also generate electrical energy, using them as a substrate for microorganisms [6,12].…”