Hexachlorobenzene removal from a model sediment by using ultrasonic irradiation

Persistent organic pollutants (POPs) are very difficult to degrade when present in the environment and finally accumulate in the human body. Therefore, it is essential to develop efficient technologies for removal of POPs from polluted sediments. In this study, the authors attempted to evaluate the potential of hexachlorobenzene (HCB; a POP) removal by using ultrasonic irradiation and its combination with other advanced chemical oxidation processes (AOPs) and surfactant addition. The average removal ratios for ultrasonic irradiation alone and ultrasonic in combination with UV light irradiation were almost identical at 40%, and the efficiency could be improved to about 49% by combination with photocatalysis or surfactant addition. The dual-frequency ultrasonic irradiation showed the highest HCB removal ratio.