Reducing the formation of disinfection by-products by pre-ozonation

The objective of this study is to apply the pre-ozonation process to reduce the formation of disinfection by-products (DBPs). The raw water sample, collected from the Te-Chi Reservoir in central Taiwan, has been polluted by fertilizer. Three types of resins were used to isolate the natural organic matter into seven types of organic fractions. The preozonation was used to oxidize each organic fraction to study the reduction of DBPs of each fraction. Experimental results indicated that the pre-ozonation could reduce the concentration of dissolved organic carbon resulting in the reduction of DBP formation, With the pre-ozonation, 9-54% of DOC and more than 40% of DBPs were reduced. With the analysis of UV adsorption and Fourier transform infrared spectrometer (FTIR), the reduction of A(254) and unsaturated functional groups such as aromatic ring and C=C bond containing in the water sample is the major reaction mechanism. (C) 2001 Elsevier Science Ltd. All rights reserved.