Occurrence of Primidone,Carbamazepine, Caffeine,and Precursors for N‐Nitrosodimethylamine in Drinking Water Sources Impacted by Wastewater1

Abstract: Wastewater impact on drinking water sources was assessed using several approaches, including analysis of three pharmaceuticals and personal care products (PPCPs) – primidone, carbamazepine, and caffeine – as indicators, and determination of precursor concentrations for the disinfection byproduct N‐nitrosodimethylamine (NDMA) using formation potential (FP) tests. Samples were collected in 2006 and 2007 in rivers impacted by wastewater treatment plant (WWTP) discharges, at drinking water treatment plant (DWTP) intakes upstream or downstream from these discharges, and from two WWTP effluents in two watersheds. The levels [10th percentile ? maximum (median)] of primidone, carbamazepine, caffeine, and NDMAFP were 2‐95 (7) ng/l, 2‐207 (18) ng/l, 7‐687 (78) ng/l, and 12‐321 (35) ng/l, respectively. The highest concentrations of primidone, carbamazepine, and NDMA precursors were from one of the WWTP effluents, whereas the highest concentration of caffeine was detected in a river heavily impacted by treated wastewater discharges. The lowest concentrations of the three PPCPs were from a DWTP influent upstream of a metropolitan urban area with minimum wastewater impact. Temporal variations in PPCP and NDMAFP concentrations and streamflows in two selected watersheds were also observed. Furthermore, correlation analysis between caffeine or carbamazepine and primidone was evaluated. The results show that measurement of the two pharmaceuticals and NDMAFP tests can be used to evaluate wastewater impact in different watersheds, whereas caffeine results were more variable.     

光致氯生水合电子降解二甲基亚硝胺的研究

采用紫外光致水合电子这一新型技术降解水中的痕量NDMA,初步研究了紫外光致水合电子对NDMA的降解效能,重点考察了NDMA的一级分解产物DMA、亚硝酸盐及硝酸盐进一步的降解情况,并与紫外直接光解进行比较。结果表明,与紫外直接光解相比,紫外光致水合电子不仅能加快NDMA本身的降解速率,还能有效地促使NDMA的分解产物进一步降解,从而达到控制NDMA的再生、降低水的化学风险的目的。这项研究对于彻底消除水中的二甲基亚硝胺污染具有一定的理论指导意义。