Awad John, van Leeuwen John, Chow Christopher W K, Smernik Ronald J, Anderson Sharolyn J, Cox Jim W
School of Natural and Built Environments, University of South Australia, South Australia, 5095, Australia.
School of Natural and Built Environments, University of South Australia, South Australia, 5095, Australia; SKLEAC, Research Centre for Eco-environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China.
Environ Pollut. 2017 Jan;220(Pt B):788-796. doi: 10.1016/j.envpol.2016.10.054. Epub 2016 Nov 4.
Dissolved organic matter (DOM) in surface waters used for drinking purposes can vary markedly in character depending on its source within catchments and the timing and intensity of rainfall events. Here we report the findings of a study on the character and concentration of DOM in waters collected during different seasons from Myponga River and Reservoir, South Australia. The character of DOM was assessed in terms of its treatability by enhanced coagulation and potential for disinfection by-product i.e. trihalomethane (THM) formation. During the wet seasons (winter and spring), water samples from the river had higher DOC concentrations (X¯: 21 mg/L) and DOM of higher average molecular weight (AMW: 1526 Da) than waters collected during the dry seasons (summer and autumn: DOC: 13 mg/L; AMW: 1385 Da). Even though these features led to an increase in the percentage removal of organics by coagulation with alum (64% for wet compared with 53% for dry season samples) and a lower alum dose rate (10 versus 15 mg alum/mg DOC removal), there was a higher THM formation potential (THMFP) from wet season waters (treated waters: 217 μg/L vs 172 μg/L). For reservoir waters, samples collected during the wet seasons had an average DOC concentration (X¯: 15 mg/L), percentage removal of organics by alum (54%), alum dose rates (13 mg/mg DOC) and THMFP (treated waters: 207 μg/L) that were similar to samples collected during the dry seasons (mean DOC: 15 mg/L; removal of organics: 52%; alum dose rate: 13 mg/mg DOC; THMFP: 212 μg/L for treated waters). These results show that DOM present in river waters and treatability by alum are highly impacted by seasonal environmental variations. However these in reservoir waters exhibit less seasonal variability. Storage of large volumes of water in the reservoir enables mixing of influent waters and stabilization of water quality.
用于饮用目的的地表水中的溶解有机物（DOM），其性质会因集水区内的来源以及降雨事件的时间和强度而有显著差异。在此，我们报告一项关于从南澳大利亚的米蓬加河和水库在不同季节采集的水样中DOM的性质和浓度的研究结果。DOM的性质是根据其通过强化混凝的可处理性以及消毒副产物（即三卤甲烷（THM）形成）的潜力来评估的。在雨季（冬季和春季），与旱季（夏季和秋季）采集的水样相比，河水水样的溶解性有机碳（DOC）浓度更高（平均值：21毫克/升），DOM的平均分子量（AMW）也更高（1526道尔顿）（旱季：DOC：13毫克/升；AMW：1385道尔顿）。尽管这些特征导致用明矾混凝去除有机物的百分比增加（雨季为64%，旱季水样为53%），明矾剂量率降低（分别为10和15毫克明矾/毫克DOC去除），但雨季水样形成THM的潜力更高（处理后水样：217微克/升对172微克/升）。对于水库水，雨季采集的水样的平均DOC浓度（平均值：15毫克/升）、用明矾去除有机物的百分比（54%）、明矾剂量率（13毫克/毫克DOC）和THM形成潜力（处理后水样：207微克/升）与旱季采集的水样相似（平均DOC：15毫克/升；有机物去除率：52%；明矾剂量率：13毫克/毫克DOC；处理后水样的THM形成潜力：212微克/升）。这些结果表明，河水中的DOM及其通过明矾的可处理性受到季节性环境变化的高度影响。然而，水库水中的这些变化表现出较小的季节性差异。水库中大量水的储存使得进水得以混合，水质得以稳定。
