Document Type : Research Article
Department of Microbiology, Science and Research branch, Islamic Azad University, Tehran, Iran
Department of Environmental Health Engineering , School of Public Health, Tehran University of Medical Science, Tehran, Iran
Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Science, Tehran, Iran
Chlorophenols are the most toxic pollutants of water and wastewater. Since 4-chlorophenol is a high soluble compound in water, it is found in water and wastewater abundantly. Because of high costs, high energy consumption and in some cases environmental inconsistency in chemical and physical removal methods, biochemical degradation of 4-chlorophenol is very important. In the present study, 13 strains of bacteria and 6 strains of yeast and mold were purified and isolated from wastewater treatment plant (Imam Khomeini seaport, Mahshahr), which lasted about 15 days. Then, the ability of each microorganism isolated in the presence of 100ppm of 4-chlorophenol was studied and two microbial species suitable for TY1 and TY2 were selected for use in mixed microbial culture. In this research, one of the most important factors affecting 4-chlorophenol degradation was by mixed microbial culture including glucose concentration with 2 and 5g/l was investigated. After examination, the microbial strains suitable for TY1 and TY2 were able to completely remove the 100ppm of 4-chlorophenol, so that the TY1 strain was removed completely after 45 hours and by TY2 strain after 21 hours and also, using a mixture of TY1 and TY2 strains (50/50) and in the presence of 2g/l glucose, 100ppm of 4-chlorophenol was completely removed after 18 hours. The significance and impact of this study was the use of indigenous strains isolated from wastewater treatment plant in petroleum refineries and petrochemical industries for the biodegradation of chlorophenol.