Efficient destruction of chlorophenols by ultraviolet irradiation

Chlorophenols (CPs), a group of recalcitrant and toxic pollutants, are widespread in the environment and threating human health. The environment-friendly technology, UV irradiation, could efficiently destruct CPs. The study investigated the influence of solution pH and positions and number of substituted chlorine atoms on photodegradation process of CPs, and also studied the photodegradation pathway. It found that the photodegradaton process of CPs was highly dependent on solution pH, and higher pH favored the degradation. The photodegradation processes agreed well with the pseudo-first order kinetics, and para- and ortho-positions and lower chlorination degree were more favorable for photodegradation of CPs. Most of the chlorine atoms were released as chloride ions, and suggest that the cleavage of the C-Cl bond occurred during the photodegradation process. It will provide some guidance for efficient treatment of CPs in water.