Ozone-enhanced photocatalytic degradation of natural organic matter in water
水中天然有机物的臭氧强化光催化降解研究

Ozone-enhanced photocatalytic degradation of macromolecular natural organic matter (NOM) in drinking water source was investigated. The influences of ozone dosage, reaction time and bicarbonate concentration on NOM degradation rate were studied. The change of molecular weight distribution of NOM caused by ozone-enhanced photocatalysis was analyzed, as well as the degradation rate of NOM with different molecular weight. It was showed that, ozone-enhanced photocatalysis was much better than sole ozonation or photocatalysis for NOM degradation. Increase of both ozone dosage and reaction time could effectively increase TOC removal rate, while the biodegradability could be improved by increase of ozone dosage solely. The existence of bicarbonate significantly reduced the photocatalytic degradation rate of NOM, however its impact was effectively offset by addition of ozone into the photocatalytic process. Macromolecular NOM was transformed into smaller molecules, and the larger NOM was much faster mineralized than smaller NOM by ozone-enhanced photocatalysis.