Study on the degraduation efficiency of chlorobenzene compounds by irradiation methods

Degradation of chlorobenzene compounds by γ-ray irradiation has been studied under various conditions. o-, m- and p-dichlorobenzene and chlorobenzene all degraded rapidly by γ-ray irradiation in methanol phase with a decreasing dechlorination rate in the order of p-, m-, o-dichlorobenzene, chlorobenzene; and both COD (chemical oxygen demand) removal efficiency and dechlorination efficiency increase with the increment of the γ-ray irradiation dose. The degradation of 1.5 mmol/L chlorobenzene in aqueous phase by γ-ray irradiation has also been studied. The results showed that higher COD removal efficiency and dechlorination efficiency were achieved in higher γ-ray irradiation doses and in O2 saturated conditions than corresponding N2 saturated conditions respectively, and pH conditions have no significant influence. In addition, degradation of chlorobenzene in aerated aqueous solutions by UV light has also been studied to further investigate the dechlorination process. The results showed that while the COD removal efficiency increases from 43% to 65%, the dechlorination efficiency remains almost constant, which implies that the released chloride atoms are likely to return to organic substances by free radical reactions. (authors)