Enhanced removal of dichloroacetonitrile from drinking water by the combination of solar-photocatalysis and ozonation

초록

In this study, the photocatalytic ozonation process using either UV lamps with a wavelength close to a solar wavelength (UVsolar) or natural solar light was established to study the effects of the major operating parameters on the removal of a toxic disinfection by-product (DBP), dichloroacetonitrile (DCAN), from drinking water. Based on the test results of a bench system, the UVsolar/TiO2/O-3 process had the highest DCAN-removal rate among the advanced oxidation processes (AOPs). The optimal TiO2 and ozone doses were 1 g L-1 and 1.13 g L-1 h(-1), respectively, while room temperature (20 degrees C) produced the highest rate constant in the kinetic tests. The kinetic rate constants linearly increased when the UVsolar intensity increased in the range 4.6-25 W m(-2); however, it increased less at intensities higher than 25W m(-2). The test results of the outdoor system showed that the solar/TiO2/O-3 process provided complete removal of DCAN that was two times faster and had about 4.6 times higher energy efficiency than with solar/TiO2. As a green oxidation technique, solar photocatalytic ozonation could be a good alternative for treating recalcitrant and toxic organic pollutants, because it has high oxidation potential and low energy consumption compared to conventional AOPs. (C) 2013 Elsevier Ltd. All rights reserved.

키워드