Phenol Degradation by Suspended Biomass in Aerobic/Anaerobic Electrochemical Reactor

Abstract

The effect of direct current (DC) on phenol biodegradation under aerobic/anaerobic condition was investigated in this study using a bioelectrochemical reactor. It was found that phenol biodegradation was inhibited with current ranged from 10 to 40 mA. The growth of biomass was reduced to 43.2 ± 6.6 % for aerobic sludge and 38.6 ± 7.3 % for anaerobic sludge, but the loosely bound extracellular polymer substances (LB-EPS) were increased 91.2 ± 1.3 % for aerobic sludge and 62.8 ± 0.8 % for anaerobic sludge as the current increased from 10 to 40 mA. Adenosine triphosphate (ATP) content of aerobic sludge was also reduced 0.481 ± 0.04-fold and 0.512 ± 0.05-fold lower and 1.34 ± 0.13-fold higher than that of the control when the current was increased from 10 to 40 mA. The results of phosphate buffer saline adding treatment indicated that lower pH caused by a DC above 10 mA was responsible for the reduced phenol biodegradation, leading to the reduction of biomass. However, lower intensity of current (5 mA) had no significant impact on phenol degradation rate, pH, LB-EPS, ATP content, and cell growth of aerobic/anaerobic sludge. These results give us a more detailed understanding of the effects of electricity on the treatment of phenol containing wastewater.

The effects of electric, magnetic and electromagnetic fields on microorganisms in the perspective of bioremediation

“…On account of the variety of processes induced by the electrostatic fields or generated by DC currents, inhibitive effects on biological activity were reported, mostly related to: (1) important variations in the pH (Fan et al 2007;Yeung and Gu 2011;Gill et al 2014;Ailijiang et al 2016), above all near the electrodes (Lear et al 2004;She et al 2006); (2) electrochemical reactions, with the production of reactive species of oxygen, chlorine or metallic ions, according to the species present in the system and the materials used for the electrodes (Liu et al 1997;Li et al 2011); (3) excessive heating because of ohmic loss (Palaniappan et al 1992;Shi et al 2008). Part of the research on these technologies focuses on investigating operation expedients for optimising the degradation processes and guaranteeing maintenance of optimal conditions for bioremediation (Jamshidi-Zanjani and Darban 2017).…”

Enhancing the Adsorption Performance of Chitosan to Phenol Derivatives through Hydrophobic Modification: Kinetics, Equilibrium, and Mechanisms

“…adsorption [11][12][13][14][15][16], biological degradation [17], persulfate-based AOPs [18], photocatalytic oxidation [8,19], electrochemical treatment [20,21], Fenton and ultrasound-Fenton oxidation [3,22,23], ozonation [24,25], and ultraviolet photolysis [26]. Among these technologies, adsorption has been recognized as one of the most promising and dependable approaches for the removal of low-concentration pollutants from wastewaters in consideration of its relatively low cost, facile operation and maintenance, high removal efficiency, and easy integration with wastewater treatment plants [27] and is widely used in the removal of phenols and other emerging contaminants in waters [12,27].…”

Effects of Constant Electric Field on Biodegradation of Phenol by Free and Immobilized Cells of Bradyrhizobium japonicum 273

“…Therefore, it is expected that electrochemical reactions on the electrode might enhance the complete microbial biodegradation of the substrate. The effects of constant electric fields on microbial activity were studied for different redox systems-namely, biodegradation of organic matter by Jobin and Namour [17] and Liu et al [18], including phenol biodegradation [19,20].…”