CeO_2/O_3催化氧化对滤后水中小分子副产物生成的影响

Effect of Catalytic Ozonation with Supported Cerium Oxide on the Formation of Low Molecular Weight Oxidation By-Products of Filtered Surface Water

考察了连续流体系中,滤后水经氧化铈催化臭氧氧化(CeO2/O3)后小分子醛、酮、羧酸及酮酸副产物的生成情况.发现CeO2/O3明显提高了DOC和SUVA的去除率,醛、酮副产物的产量比单独O3氧化后的增加了8%,而羧酸和酮酸的产量却比单独O3氧化后的分别降低了28%和54%.羧基类副产物大幅降低的原因主要与CeO2表面Ce(Ⅳ)对羧基官能团较强的络合亲合力有关.CeO2/O3氧化后小分子副产物总量比单独O3氧化后的降低了23%,但用小分子副产物总量折算有机碳占DOC的比例来间接显示氧化后剩余DOC的可生物降解性,结果表明,CeO2/O3进一步提高了滤后水剩余DOC的可生化性.

The aim of the work is to investigate the formation of the low molecular weight（LMW）oxidation by-products（i.e.aldehydes,ketones,carboxylic acids and ketoacids）after cerium oxide-catalyzed ozonation（CeO2/ O3）of filtered waters in a continuous flow reactor.Results showed that CeO2/O3 can evidently improve the reduction of the dissolved organic matter（DOC）and specific UV absorbance（SUVA）.Compared with ozonation alone,CeO2/O3 caused an increment of the formation of aldehydes and ketones by about 8%,and a significant reduction of the formation of carboxylic acids and ketoacids by 28% and 54%,respectively.The great reduction of carboxyl group by-products is mainly attributed to the high affinity of Ce（Ⅳ）to the carboxyl group on the surface of CeO2 during CeO2/O3 oxidation.The total production of LMW by-products reduced by 23%.However,the filtered water became more biodegradable after catalytic ozonation,because the percentage of total LMW by-products carbon in the final DOC after catalytic ozonation was higher than that after ozonation alone.