Photochemical Degradation of Organics in Water

Abstract

Abstract Trichloroethylene, phenol, 4-cholorophenol, catechol and a pesticide were degraded by two advanced oxidation processes: photolytic oxidation with hydrogen peroxide, andphotolytic oxidation with ozone. The reactions were studied in a batch photoreactor with a low pressure mercury lamp as the radiation source. The variation of the concentration of total organic carbon with time was measured. For the organics studied, the reaction kinetics for the reduction of total organic carbon (TOC) were found to follow a power law. The exponent of the power law varies with the initial TOC concentration. Results show that TOC can be very effectively reduced provided the concentration of hydrogen peroxide used exceeds a certain threshold value. The UV/Ozone process yielded a more rapid rate of degradation and a greater degree of mineralisation.