Biological Degradation of 2,4,6-Trichlorophenol by a Sequencing Batch Reactor

Abstract

2,4,6-trichlorophenol (TCP) is a toxic compound which is released into the environment mainly through industrial wastewater. For aerobic biological degradation of TCP, a modified bench scale SBR was used. The biological sludge of municipal wastewater treatment plant was used to set up the bioreactor. In order to reduce the release of TCP, the SBR was modified by increasing the ratio of constant volume to total volume of the bioreactor, increasing the ratio of height to diameter, reducing the number of operating cycles per day and entering wastewater from the floor of the bioreactor. The amount of TCP volatility with the gases from SBR was determined by adsorbing and extracting it from powder activated carbon column. The modified SBR in TCP concentration of 430 mg/L and HRT of 8 h removed more than 99% of TCP and total phenolic compounds (TP) as well as more than 92% of COD. Also, more than 90% of chloride ions were stoichiometrically released from TCP. Finally, the modified SBR was capable of removing TCP in concentration of 430 mg/L at a low hydraulic retention time (8 h). This is the first study to report these results, where the modified SBR could operate at higher concentrations of TCP and in shorter HRT. Therefore, the modified SBR can be used as a reliable and effective process to remove TCP and other halogenated compounds.