氣候變遷對飲用水水質及消毒副產物生成影響之研究

The Potential Impacts of Climate Change on Drinking Water Quality and Disinfection By-products Formation

黃祉瑄(Chih-Hsuan Huang)

指導教授 ： 王根樹

國立臺灣大學/公共衛生學院/環境衛生研究所/碩士(2017年)

https://doi.org/10.6342/NTU201703769

摘要

人為活動所引起的全球氣候快速變遷已對生態系統及人類生活造成諸多影響，其中，氣候變遷對水資源的衝擊及飲用水水質安全的潛在影響尤其受到重視。
全球暖化及海平面上升都是可觀察到的氣候變遷結果，且這些變化可預期將持續發生。已有研究指出溫度升高會改變水中溶解性有機物質(Dissolved organic matter, DOM)之特性及濃度，海平面上升則會導致受到海水入侵之區域水中溴離子濃度增加。DOM是消毒副產物(Disinfection by-products, DBPs)的重要前趨物質，在自來水廠淨水處理流程中會與消毒劑反應生成具健康危害的消毒副產物，而溴離子亦是已知影響消毒副產物生成的因子之一。因此，本研究係以在實驗室模擬不同溫度條件及原水中溴離子濃度，探討全球暖化及海平面上升對飲用水水質及消毒副產物生成之潛在影響。並藉由實驗室杯瓶試驗模擬淨水廠現行之傳統淨水處理程序，以評估其對氣候變遷可能導致的飲用水水質安全問題之調適性。
實驗室模擬結果顯示，水樣在較高的溫度(35 °C)下會促進微生物活動並分解水中溶解性有機物質，導致水中溶解性有機碳濃度及消毒副產物生成潛能下降。但此趨勢會因原水水質特性不同而有所差異。水中溴離子濃度增加將生成具有較強鹵素取代能力的HOBr，使消毒副產物之物種分布傾向於含溴物種之生成，此外；總三鹵甲烷(Trihalomethanes, THMs)及含鹵乙腈(Haloacetonitriles, HANs)的生成潛能亦隨溴離子濃度增加而增加，總含鹵乙酸(Haloacetic acids, HAAs)的增加趨勢則不明顯。
淨水處理程序模擬結果顯示傳統混凝沉澱及過濾流程對原水中THMs前趨物質的去除效果最佳，HANs次之，使後續加氯消毒步驟中生成之THMs及HANs濃度明顯下降；HAAs的濃度則沒有明顯變化，而鹵化酮(haloketons, HKs)的濃度反而增加。此外，在經過傳統淨水程序處理的水樣中，溫度對消毒副產物生成的影響並不明顯，但依然可以觀察到原水中溴離子濃度對消毒副產物的影響，總HAAs及HANs濃度隨原水中溴離子濃度增加而增加的情況甚至更明顯。

關鍵字

氣候變遷 ； 實驗室模擬 ； 傳統處理 ； 飲用水水質 ； 消毒副產物

並列摘要

The potential effects of climate change have already been observable on ecosystem and several aspects of human lives. One of the critical concerns is the adversely affect to water resources and bring impacts on drinking water quality.
Scientific studies demonstrated that the average surface temperature has increased and sea level has risen in the past 100 years; moreover, global climate is expected to change further in the future. Previous studies have indicated that temperature can affect the physico-chemical equilibriums, biological reactions as well as the concentrations and characteristics of dissolved organic substance (DOM) in water. Sea level rise could cause saltwater intrusion and lead to increase of bromide concentrations in water sources. DOM is an important precursor of various disinfection by-products (DBPs); bromide concentration in source water is also an important factor which affects the DBPs formation. The objectives of this study is to characterize the effects of the various climate-related factors including temperature and sea level rise on drinking water quality and DBPs formation based on laboratory simulations. In addition, simulations of conventional water treatment processes by jar-tests (coagulation) and filtration were also conducted to assess whether the conventional water treatment processes has abilities to adapt to the potential deteriorations of raw water quality resulted from climate change.
The results of simulation experiments showed that both the non-purgeable dissolved organic carbon concentration and the formation of DBPs in water samples were decreased at higher temperature (35 °C) due to increased microbial activities which lead to more degradation of organic substances and further affect DBPs formation. However, the effects of temperature on DBPs could vary owing to various characteristics of source water. When bromide was presented in water sources, the proportions of Br-DBPs were increased because of the stronger halogenation ability of HOBr. The concentrations of total THMs and HANs were also increased markedly when bromide level increased; while the increasing trend was not remarkable for total HAAs.
The results of simulated conventional water treatment processes showed that THMs precursors can be effectively removed by coagulation and filtration processes, and HANs take second place thus the concentrations of THMs and HANs were decreased. In contrast, no apparent changes were observed for the concentrations of HAAs; and the concentrations of HKs were increased. After coagulation treatments, the effects of incubation temperature can be ignored. However, the effects of bromide level could still be observed and even more apparent on HAAs and HANs.

並列關鍵字

climate change ； laboratory simulation ； conventional water treatment processes ； drinking water quality ； disinfectant by-products

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