Effect of colloids on the occurrence, distribution and photolysis of emerging organic contaminants in wastewaters.

作者：Yan Caixia, Nie Minghua, Yang Yi*, Zhou Junliang, Liu Min, Mohammed Baalousha, Jamie R. Lead

The effect of colloids on the occurrence, phase distribution and photolysis of twenty-seven emergingorganic contaminants (EOCs) was studied in domestic and livestock wastewaters (DW and LW), respec-tively. Filtered water (<1μm) was separated into permeate (<1 kDa) and retentate (1 kDa-1μm) by crossflow ultrafiltration. Results indicated that total concentration of EOCs ranged from 1220 ng L−1 in per-meate of DW to 5065 ng L−1 in retentate of LW. The average EOC fraction associated with colloids was13.5% and 14.4% in DW and LW. Most of the EOCs exhibited pseudo-first-order degradation kinetics inall water samples. Control experiments using glass and quartz reactors showed that UV light was moreeffective on the photolysis of most EOCs. The EOCs photolysis in the three fractions of DW and LW could beaccelerated or inhibited compared to ultrapure water with the enhancement factor ranging from -0.94 to 7.33. The impact of colloids on the photolysis of EOCs depended on the compound and the source ofwater. The photolysis of most EOCs in permeates and filtrates was generally accelerated, while inhibitedin the retentates, which could be attributed to the relatively high dissolved organic carbon contents inretentates.

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