Cathodic reduction characteristics of 2-chloro-4-nitrophenol in microbial electrolysis cell

Abstract

Microbial electrolysis cell (MEC) has been constructed to study the degradation characters of 2-chloro-4-nitrophenol (2C4NP) in waste water. The effects of applied voltage, initial concentration of substrate and co-matrix species on the reduction and degradation of 2C4NP were studied. Qualitative and quantitative analysis of 2C4NP residues and degradation intermediate by using UV-Vis, HPLC, HPLC/MS/MS, IC and other analytical testing techniques. The degradation mechanism of 2C4NP in MEC cathode was proposed. The results showed that electron and electroactive microorganisms would produce coupling effect and accelerate the degradation of 2C4NP under adding 0.5 V DC; Under the condition of satisfying the C/N ratio of electroactive anaerobic microorganism, the addition of organic substances such as glucose and sodium acetate which were easily degraded by microorganisms would hinder the degradation of 2C4NP in the cathode compartment. 2C4NP can be effectively degraded by adding appropriate amount of glucose as carbon source with the low C/N. 2C4NP undergoes reduction, dechlorination, denitrification and assimilation in the cathode compartment to form 2-chloro-4-aminophenol, 4-aminophenol, 2-chlorophenol, 2-chloro-4-hydroxyphenol, nitrophenol, hydroquinone, 4-hydroxyhexadienoic acid semialdehyde, valeric acid, oxalic acid and many other intermediate products. According to the degradation intermediates, the degradation mechanism of 2C4NP in the cathode compartment was presumed.

Recent advances in biological approaches towards anode biofilm engineering for improvement of extracellular electron transfer in microbial fuel cells

“…EPS production, chemotactic processes, and cell migration play an important role during the degradation of organic pollutants or purification. It is found that gene modification of QS may assist in creating designed biofilms with enhanced degradation kinetic models and increase the performance of MFCs [84]. Moreover, a rhamnolipid synthesis which QS controls contributes to biofilm design by maintaining open biofilm water channels during matrix growth [85].…”

Validity and Reproducibility of Counter Electrodes for Linear Sweep Voltammetry Test in Microbial Electrolysis Cells

“…Therefore, the purpose of this study was to evaluate the reproducibility of using different counter electrodes for anode and cathode LSV tests in a microbial electrolysis cell (MEC). The anode and cathode used in the experiment were carbon fiber brush and stainless steel mesh commonly used in MECs [60,61]. To compare reproducibility, the counter electrodes used in this study were Pt wire, stainless steel wire, and mesh in anode LSV tests.…”