Optimizing rapid pentachlorophenol biodegradation using response surface methodology

Abstract

Pentachlorophenol (PCP) is one of the most toxic pollutants in the environment during modern industrial processes. Statistical experimental designs based on biological methods optimized the PCP biodegradation by Bacillus mucilaginosus and Pseudomonas plecoglossicida. Four factors were selected for PCP removal; glucose, ferric ammonium citrate, PCP concentration, and incubation period. PBD and CCD were performed to recognize the maximum PCP biodegradation. The maximum PCP biodegradation in PBD by B. mucilaginosus was obtained at glucose, 0.5 (g/l); ferric ammonium citrate, 0.5 (g/l); PCP concentration, 300 (mg/l) and incubation period, 3 (days) while the maximum conditions by P. plecoglossicida were glucose, 0.5 (g/l); ferric ammonium citrate, 0.5 (g/l); PCP concentration, 100 (mg/l) and incubation period, 3 (days). In addition, CCD predicted the optimum predicted degradation of PCP (100%) by the two selected strains using glucose (1.0 g/l), ferric ammonium citrate (0.059 mg/l), PCP concentration (350 mg/l), and 2-days for B. mucilaginosus. While glucose (0.276 g), ferric ammonium citrate (0.047 mg/l) and 2-days were optimal conditions for P. plecoglossicida. P. plecoglossicida.and B. mucilaginosus could degrade more than 72% and 61% of PCP when these isolates were grown under a high concentration of PCP (300 and 350 mg L−1) in a mineral salt medium, respectively.