• 关键词：溶解性有机物  光降解  冰体  天然太阳辐射作用  分级

• 基金项目：国家自然科学基金(No. 21107039);辽宁省教育厅科学技术研究项目(No. L2011002);辽宁省科学技术计划项目(No.2011230009)

• 薛爽
• 辽宁大学 环境学院, 沈阳 110036

• 王超
• 辽宁大学 环境学院, 沈阳 110036

• 马溪平
• 辽宁大学 环境学院, 沈阳 110036

• 刘强
• 辽宁大学 环境学院, 沈阳 110036

• 景逵
• 辽宁大学 环境学院, 沈阳 110036

• 艾娇
• 辽宁大学 环境学院, 沈阳 110036

• 李丽丹
• 辽宁大学 环境学院, 沈阳 110036

• 摘要：利用XAD树脂对沈阳市细河河水中的溶解性有机物(DOM)进行分级分离.按照DOM在XAD树脂上的吸附特性将其分为5个部分:疏水性有机酸(HPO-A)、疏水性中性有机物(HPO-N)、过渡亲水性有机酸(TPI-A)、过渡亲水性中性有机物(TPI-N)和亲水性有机物(HPI).研究了天然太阳辐射作用下冰体中DOM组分的光降解特性.结果表明:太阳辐射作用下,冰体中的5种DOM组分均会发生光降解,其中HPO-A的光降解程度最高.光照80 h后,冰体中HPO-A、HPO-N、TPI-A、TPI-N和HPI的UV-254去除率分别为43.4%、44.15%、45.9%、55.0%和58.8%.光降解作用对冰体中的荧光物质具有显著的去除效果.除了HPO-A中的类芳香族蛋白质荧光物质(Ⅰ)之外,DOM组分中的各类荧光物质的光降解程度均高于以DOC表征的整体有机物的光降解程度.光降解对DOM组分中类富里酸荧光物质和类腐殖酸荧光物质的去除效果优于对类溶解性微生物代谢产物荧光物质和类芳香族蛋白质荧光物质的去除效果.在冰体中DOM组分的光降解过程中,既发生THMs前体物的去除,也发生THMs前体物的生成.光降解使HPO-A中THMs前体物的量减少,使TPI-N中THMs前体物的量增加,而其他3种组分中THMs前体物的量的变化与光照时间有关.

• Abstract：Dissolved organic matter (DOM) in the Xihe River in Shenyang was fractionated using XAD resins into 5 fractions:hydrophobic acid (HPO-A), hydrophobic neutral (HPO-N), transphilic acid (TPI-A), transphilic neutral (TPI-N) and hydrophilic fraction (HPI). The photodegradation of DOM fractions in ice under natural solar radiation was investigated. The results showed that the photodegradation of five DOM in ice occurred under solar radiation, and the photodegradation efficiency of HPO-A was the highest. The UV-254 removal rates of HPO-A, HPO-N, TPI-A, TPI-N and HPI in ice were 43.4%, 44.15%, 45.9%, 55.0% and 58.8%, respectively, after 80 h solar radiation. The reductions of fluorescent materials in ice in the photodegradation process were significant. Except for aromatic protein-like fluorescent materials (Ⅰ) in HPO-A, the photodegradation efficiencies of all types of fluorescent materials in DOM were higher than those of the bulk organics represented by dissolved organic carbon (DOC). The removal rates of fulvic acid-like and humic acid-like fluorescent materials in DOM in the photodegradation process were higher than those of soluble microbial byproduct-like and aromatic protein-like fluorescent materials. The reductions, as well as the productions, of trihalomethanes (THMs) precursors occurred in the photodegradation of DOM in ice. The photodegradation resulted in the decrease of THMs precursors in HPO-A, as well as the increase of THMs precursors in TPI-N. On the other hand, the changes in the content of THMs precursors in the other three fractions were related to solar irradiation time.

• Key words：photodegradation  dissolved organic matter  ice  natural solar radiation  fractionation

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