Biodegradation of 2,4-dichlorophenol originating from pharmaceutical industries

The aims of this work were to isolate a microorganism from the wastewater of pharmaceutical industries, to examine the difference in its growth utilization of 2,4-dichlorophenol as the sole carbon source pre and post-exposure to UV-irradiation and to investigate its efficiency of biodegradation at different temperatures and pH values using a laboratory benchtop bioreactor. Sludge was obtained from the wastewater and standard isolation and identification techniques were used to identify the microorganism. The biodegradability was tested at temperatures of 25, 30, 35 and 40C and at pH values of 6.5, 7.0 and 8.0. The results indicated that the isolated microorganism was Pseudomonas alcaligenes, the maximum concentration of 2,4-dichlorophenol which bacteria can grow on before UV-irradiation was 220 and 380 mg/l after UV-irradiation. The variation in temperature values resulted in different degradation rates and that the degradation of 2,4-dichlorophenol increased at a higher pH value. From these results, it is concluded that P. alcaligenes can be used for the degradation of 2,4-dichlorophenol, UV-irradiation can be successfully used for the improvement of P. alcaligenes biodegradability and that the best 2,4-dichlorophenol biodegradation was at 35C and pH 7.