Co-metabolic biodegradation of 4-bromophenol in a mixture of pollutants system by Arthrobacter chlorophenolicus A6

Abstract

Brominated phenols are listed as priority pollutants, and are the key components of paper pulp wastewater together with nitrophenol and chlorophenol. However, the biodegradation of bromophenol in a mixed substrate system is very scanty. In the present investigation, simultaneous biodegradation kinetics of three substituted phenols were investigated using Arthrobacter chlorophenolicus A6. A 2 3 full factorial design was applied with varying 4-BP and 4-CP from 75-125 mgl − 1 and4-NP from 50-100 mgl − 1 . Almost complete degradation of this mixture of substituted phenols was achieved at an initial concentration combination of 125, 125, and 100 mgl − 1 of 4-CP, 4-BP, and 4-NP, respectively in 68 h. Statistical analysis of the results revealed that among the three variables, 4-NP had the most prominent in uence on both degradations of 4-CP and 4-BP. While the concentration of 4-CP had a strong negative interaction effect on the biodegradation of 4-NP. Irrespective of the concentration levels of these three substrates, 4-NP was preferentially biodegraded over 4-CP and 4-BP. Further, 4-BP biodegradation rates were found to be higher than that of 4-CP followed by 4-NP. Besides, the variation of biomass yield coe cient of the culture was investigated at different initial concentration combinations of these substituted phenols. Although the actinomycetes consumed 4-NP at a faster rate, the biomass yield was very poor. This revealed that the microbial cells were more stressed when grown on 4-NP compared to 4-BP and 4-CP. Overall, this study revealed the prospective of A. chlorophenolicus A6 for the degradation of 4-BP in mixed substrate systems.

Facile synthesis of C30-AuNPs for the effective catalytic reduction of nitrophenols and azo dyes

“…The US Environmental Protection Agency has reported that 4-NP is carcinogenic, hepatotoxic and mutagenic, posing a significant risk to human life and health, and it has been placed on the US EPA's Priority Pollution List. [6][7][8][9][10] In recent years, electrochemical treatment, 11 photocatalytic degradation, 12 microbial degradation, 13 microwave catalytic oxidation, 14 electrocoagulation and adsorption 15 have been used to resolve the hazards of 4-NP pollutants. However, it has been found that the conversion of 4-NP by these methods is low and costly, and therefore, the green and simple reduction of 4-NP has received extensive attention.…”