Study of 4-Chlorophenol Biological Treatment Using Yeast and Mold Isolated From Industrial and Petroleum Wastewaters (Imam Khomeini Port, Mahshahr)



Alirezaei A¹ ; Bayat M¹ ; Alimohmmadi M² ; Hashemi S³
Source: Bulgarian Chemical Communications Published:2018

Abstract

Phenolic derivatives are some of the most toxic pollutants in the environment. Chlorophenols are the most toxic pollutants of water and wastewater. Since 4-chlorophenol is a highly soluble compound in water, it is abundantly found in water and wastewater. Because of high costs, high energy consumption and in some cases environmental inconsistency of the chemical and biological removal methods, biochemical decomposition 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 Shahid Tondgooyan wastewater treatment plant (Imam Khomeini Port, Mahshahr), which lasted about 15 days. Then, the ability of each microorganism isolated in the presence of 100 ppm of 4-chlorophenol was studied and two microbial species suitable for TY1 and TY2 were selected for use in a mixed microbial culture. 4-Chlorophenol decomposition was performed in the presence of 100 ppm of 4-chlorophenol. In this research, one of the most important factors affecting 4-chlorophenol degradation by mixed microbial culture including glucose concentration with 2 and 5 g/l was investigated. After examination, the microbial species suitable for TY1 and TY2 were able to completely remove 100 ppm of 4-chlorophenol, so that the TY1 strain was removed completely after 45 h and the TY2 strain after 21 h. Using a mixture of TY1 and TY2 strains (50/50) in the presence of 2 g/l of glucose, 100 ppm of 4-chlorophenol were completely removed after 18 h. Based on the 18SrRNA gene sequence analysis, the molecular identification of the two superior strains was carried out, both belonging to the genus Trichosporon. Considering the high potential of Trichosporon species, including their potential applications in increasing oil recovery and eliminating pollutants, it would be hoped that the further exploration of strains characteristics and the search for new native strains could play a crucial role in the application of native strains in the oil industry. © 2018 Bulgarian Academy of Sciences, Union of Chemists in Bulgaria