Formation potential and analysis of 32 regulated and unregulated disinfection by-products: Two new simplified methods

Water disinfection is an essential process that provides safe water by inactivating pathogens that cause waterborne diseases. However, disinfectants react with organic matter naturally present in water, leading to the formation of disinfection by-products (DBPs). Multi-analyte methods based on mass spectrometry (MS) are preferred to quantify multiple DBP classes at once however, most require extensive sample pre-treatment and significant resources. In this study, two analytical methods were developed for the quantification of 32 regulated and unregulated DBPs. A purge and trap (P&T) coupled with gas chromatography mass spectrometry (GC-MS) method was optimized that automated sample pre-treatment and analyzed volatile and semi-volatile compounds, including trihalomethanes (THMs), iodinated trihalomethanes (I-THMs), haloacetonitriles (HANs), haloketones (HKTs) and halonitromethanes (HNMs). LOQs were between 0.02-0.4 µg/L for most DBPs except for 8 analytes that were in the low µg/L range. A second method with liquid chromatography (LC) tandem mass spectrometry (MS/MS) was developed for the quantification of 10 haloacetic acids (HAAs) with a simple clean-up and direct injection. The LC-MS/MS direct injection method has the lowest detection limits reported (0.2-0.5 µg/L). Both methods have a simple sample pre-treatment, which make it possible for routine analysis. Hyperchlorination and uniform formation conditions (UFC) formation potential tests with chlorine were evaluated with water samples containing high and low TOC. Hyperchlorination formation potential test maximized THMs and HAAs while UFC maximized HANs. Ascorbic acid was found to be an appropriate quencher for both analytical methods. Disinfected drinking water from four water utilities in Alberta, Canada were also evaluated.     

操作条件及水质对海水氯消毒过程中消毒副产物生成的影响

氯消毒广泛应用于海水利用的预处理过程中,以减少生物膜淤积,而消毒过程会导致各类消毒副产物(DBPs)的生成,可能会对海洋生态环境具有潜在危害。系统研究了操作条件和水质对海水氯化消毒过程中生成三卤甲烷(THMs)、卤乙腈(HANs)和卤乙酸(HAAs)的影响。结果表明,氯投加量对DBPs生成的影响最大,随着投氯量的增加,THMs、HANs和HAAs的生成量显著增加,在反应初期随反应时间的延长而增加,随后HANs和HAAs的生成量开始缓慢降低而THMs基本保持不变。随着温度升高,THMs的生成量稳步增加,而HAAs和HANs在分别达到30,25℃后生成量达到最大值,之后随温度的升高而降低。p H对THMs、HANs和HAAs生成的影响相反,在酸性条件下HANs和HAAs的生成量最多,而在碱性条件下THMs的生成量最多。THMs、HANs和HAAs的生成量随溴离子浓度的改变无明显变化,但是随着氨氮浓度的升高,THMs、HANs和HAAs的生成种类和生成量均有明显降低。