Dynamics and trihalomethane formation potential of recalcitrant dissolved organic matter in lake water

湖水中难溶解有机物的动态和三卤甲烷形成潜力

• 批准号: 12450215
• 负责人: IMAI Akio
• 金额: $ 7.17万
• 依托单位: National Institute for Environmental Studies
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12450215/
• 关键词: dissolved organic matter (DOM); recalcitrant DOM; lake water; trihalomethane formation potential; aquatic humic substances; hydrophilic DOM; river water; molecular weight; 離分解性溶存有機物; 難分解性有機物; トリハロナタン生成能; 親水性有機物

Dissolved organic matter (DOM) in water from eutrophic Lake Kasumigaura, its inflowing rivers, and several other DOM sources in the lake catchment area was fractionated using a long-term biodegradation test and resin adsorbents into ten classes: aquatic humic substances (AHS), hydrophobic neutrals (HoN), hydrophilic acids (HiA), bases (BaS), hydrophilic neutrals (HiN), and recalcitrant AHS, HoN, HiA, BaS, and HiN. The DOM-fraction distribution pattern, the trihalomethane formation potential (THMEP, μmol・mgC^<-1>) and molecular size distribution of the DOM, AHS and the hydrophilic fractions (HiF=HiA+BaS+HiN) were evaluated.DOM-fraction distribution patterns were significantly different depending on the origin of the sample. AHS and HiA ware found to be the dominant fractious in DOM in all samples studied. HiA prevailed over AHS in the lake water, whereas AHS were slightly more abundant than HiA in the river waters. AHS were in the great majority in forest streams and plowed-field percolates. R-DOM fraction distribution patterns clearly indicated that the dominant recalcitrant DOM fraction is HiA not AHS in the lake water, whereas AHS prevailed over HiA in the river-water R-DOM. The THMFP of HiF was found to be comparable to that of AHS in the lake water. The importance of HiF over AHS as a THM precursor became pronounced when THMFP was evaluated in terms of concentration (μmol・L^<-1>). Molecular size distributions all exhibited a narrow size range and relatively low molecular weights. The weight-averaged molecular weights of DOM, AHS and HiF were 780, 960 and 610 g-mole^<-1>, respectively.

以富营养化的霞浦湖、入湖河流和其他几种DOM源为研究对象，采用长期生物降解试验和树脂吸附法，将湖水中的DOM分为10类：水生腐殖物质（AHS）、疏水中性物质（HoN）、亲水酸（HiA）、碱性物质（BaS）、亲水中性物质（HiN）和水生腐殖物质（AHS）、疏水中性物质（HoN）、亲水中性物质（HiA）、亲水中性物质（BaS）和水生腐殖物质（HiN）。对<-1>DOM、AHS和亲水性组分（HiF=HiA+BaS+HiN）的DOM组分分布模式、三卤甲烷生成势（THMEP，μmol·mgC^）和分子大小分布进行了评价。AHS和HiA是DOM的主要组分。在湖水中，HiA优于AHS，而在河水沃茨中，AHS略多于HiA。AHS绝大多数存在于森林溪流和耕地渗滤液中。R-DOM组分的分布格局表明，湖水中的优势有机质组分是HiA而不是AHS，而河水中的优势有机质组分是AHS而不是HiA。结果表明，HIF的THMFP与AHS在湖水中的THMFP相当。当以浓度（μmol·L^）评价THMFP时，HiF作为THM前体的重要性超过AHS<-1>。分子大小分布都表现出窄的尺寸范围和相对较低的分子量。DOM、AHS和HiF的重均分子量分别为780、960和610克-摩尔%<-1>。