Studies on treatment of chlorophenol-containing wastewater by microbial fuel cell

Abstract

A microbial fuel cell with 4-CP as oxidant was established to investigate the feasibility of 4-CP dechlorination in the cathodic chamber of MFC. It demonstrated good performance on electricity generation with P max 12.4 mW/m 2 and CE 22.7%. Besides, 60 mg/L 4-CP could be completely dechlorinated in 45 h in the MFC, and 4-CP dechlorination process and electricity generation process had obvious synergistic effect. microbial fuel cell, chlorophenol, oxidant, dechlorination Microbial fuel cell (MFC) is a device that converts chemical energy to electrical energy with aid of the catalytic reaction of microorganisms [1] . It has been shown that continuous electricity generation can be obtained by using a range of biodegradable fuels including pure substrates such as acetate [2] and organic pollutants in wastewater [3][4][5] . When using anaerobic sludge as inoculants and organic pollutants as fuel in the anodic chamber of MFC, both wastewater treatment and electricity generation could be achieved. Hence, MFC provides a new idea for environmental protection and energy recovery.Researches on oxidants, such as oxygen, potassium ferricyanide, and potassium permanganate [6] , have so far concentrated primarily on their ability of accepting electrons and protons. The effect of cathodic chamber on electricity generation was just to form the pass way for electrons and protons yet. Therefore, if using certain pollutant which had the ability of accepting electrons and protons as oxidant, the cathodic chamber of MFC, as well as its anodic chamber could harvest considerable energy from pollutants. Hence it showed great potential for improving the environmental benefits of the MFC. Few researches on this aspect have been reported so far.Chlorophenol compound is one of the prior controlled organic pollutants in drinking water because of its carcinogenesis. The standard reduction potential of 4-chlorophenol (4-CP) is between +0.5 and +1.5 V, and the standard anode potential in MFC is approximately -0.296 V under typical conditions. Therefore, MFC with 4-CP as oxidant is theoretically feasible. The open circuit voltage could reach approximately +0.8-+1.8 V, similar to that of MFC with oxygen as oxidant [1] .In this study, a two-chamber MFC with 4-CP as oxidant was operated with acetate as fuel to investigate its performance of electricity production and ability of wastewater treatment. Furthermore, the feasibility of the MFC with 4-CP as oxidant was evaluated according to the results of this study.The experimental set-up is shown in Figure 1. The anode and cathode compartments (working volume of 200 mL each) of the MFC were separated by proton exchange membrane (PEM) (Nafion 117, Dupont, USA). Carbon fibres (effective area of 20 cm 2 and mass weight of 0.3 g) were used as electrodes with copper wire connecting them through resistance (245 Ω) and a multimeter (UT70B, UNI-T, HK). The whole reactor was located in a constant temperature room with 25℃.Inoculation sludge was cultivated by incubating an-

Bioelectrochemical systems for efficient recalcitrant wastes treatment

“…41,42 Nitrobenzene, azo dye of Acid Orange 7 and chlorinated organic of 4-chlorophenol can be reduced in an abiotic cathode, with concomitant energy recovery. 24,25,43,44 pH at the cathode was proved to strongly affect power production and removal of these recalcitrant wastes. 24,25 Additionally, the reductant usage ratio defined as the ratio of electrons available at the anode and consumed at the cathode was 3-6 times as high as the theoretical values, indicating the inefficiency of anodic electrons.…”

“…24,25 Additionally, the reductant usage ratio defined as the ratio of electrons available at the anode and consumed at the cathode was 3-6 times as high as the theoretical values, indicating the inefficiency of anodic electrons. 43 Fine-tuning of the anodic potential and loading will allow minimization of the electron losses and thus improve the performance of BESs for recalcitrant wastes treatment. 24,25,37 Besides the recalcitrant organics, some recalcitrant heavy metals with high redox potentials such as Cr(VI), V(V), Cu(II), U(VI) and Se(VI) can also be successfully used as electron acceptors in abiotically cathodic MFCs.…”

Electricity production during the treatment of real electroplating wastewater containing Cr6+ using microbial fuel cell

“…And a maximum power density of 115.6 mW/m 2 was generated [27]. Gu et al revealed that a maximum power density of 12.4 mW/m 2 was generated using 50 ppm chlorophenol as the electron acceptor [28]. In contrast to potassium permanganate and chlorophenol, potassium dichromate was a more favorable electron acceptor, showing a higher power density of MFC.…”

“…Therefore, if using certain pollutant with the ability of accepting electrons and protons as oxidant, the cathode chamber of MFCs, as well as the anode chamber could harvest considerable energy from pollutants. This would greatly enhance the environmental benefit of MFCs [28]. Based on this hypothesis, electroplating wastewater containing Cr 6+ was chosen as the cathodic electron acceptor in this study.…”

Kinetic Sorption of 2,4-Dichlorophenol and Rhodamine-B from Aqueous Solutions onto Modified Phragmites Australis

“…They have been considered as priority water pollutants by the United States Environmental Protection Agency (EPA) and Environmental Monitoring of China, because of their high toxicity to organisms at low concentrations [3,4]. Since most of the dyes are biologically non-degradable, it is difficult to remove them from wastewater.…”