Moody Catherine S, Bell Nicholle G A, Mackay C Logan, Kitson Ezra
water@leeds, School of Geography, University of Leeds, Leeds LS2 9JT, U.K.
School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K.
ACS ES T Water. 2025 Apr 29;5(5):2233-2243. doi: 10.1021/acsestwater.4c01113. eCollection 2025 May 9.
Drinking water is becoming more difficult to treat, especially in the UK, due to the changing concentration and composition of aquatic dissolved organic matter (DOM). The spatial and temporal variations in the DOM composition are not well understood. This study investigated how DOM composition varies along a north/south gradient in the UK, over four years, and between headwaters and reservoirs. There were trends in DOM composition metrics from north to south; carbohydrate and peptide-like compounds were lower in northern sites, while lipid-like compounds were lower further south, suggesting different sources of DOM in north/south catchments. DOM collected in Autumn 2021, after a Summer of low rainfall, was more aromatic, less oxidized, and more diverse than DOM collected in 2018-2020. Decreased lipid content and increased oxy-aromatic content occurred in Autumn, at the end of the plant growing season, when increased rainfall rewets catchments and mobilizes soil OM into surface waters. These seasonal changes in DOM composition coincide with increased DOM concentrations in raw drinking water, leading to more challenges for drinking water treatment, especially as climate change alters rainfall distribution in the UK.
由于水中溶解有机物（DOM）的浓度和组成不断变化，饮用水的处理变得越来越困难，尤其是在英国。人们对DOM组成的时空变化了解不足。本研究调查了英国境内四年间DOM组成沿南北梯度的变化情况，以及源头水和水库之间的差异。DOM组成指标存在从北到南的变化趋势；北部地区碳水化合物和类肽化合物含量较低，而南部地区类脂化合物含量较低，这表明南北流域的DOM来源不同。在2021年秋季降雨量较低的夏季之后采集的DOM，比2018 - 2020年采集的DOM更具芳香性、氧化程度更低且种类更多。秋季，在植物生长季节结束时，随着降雨量增加使集水区重新湿润并将土壤有机质转移到地表水，DOM的脂质含量降低，氧芳香族含量增加。DOM组成的这些季节性变化与原水饮用水中DOM浓度的增加相吻合，给饮用水处理带来了更多挑战，尤其是在气候变化改变英国降雨分布的情况下。
