两种分子量分级下DOM的组分特征及其生物毒性  

The spectral characteristics and biotoxicity of fractions obtained from two different DOM molecular weight fractionation methods

作　　者：马晓妍 陈文凤 成芳德 唐磊 王晓昌[1] 林雨 刘孝坤[2] MA Xiao-yan;CHEN Wen-feng;CHENG Fang-de;TANG Lei;WANG Xiao-chang;LIN Yu;LIU Xiao-kun(Key Laboratory of Northwest Water Resource,Environment and Ecology,Ministry of Education,School of Environmental and Municipal Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;XI'AN Municipal Engineering Design&Research Institute CO.LTD.,Xi'an 710068,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院,西北水资源与环境生态教育部重点实验室,陕西西安710055 [2]西安市政设计研究院有限公司,陕西西安710068

出　　处：《中国环境科学》2021年第12期5885-5895,共11页China Environmental Science

基　　金：国家自然科学基金资助项目(52170050,51979217);陕西省教育厅重点科研计划新型智库项目(21JT027);陕西省自然科学基础研究项目(2020JQ-663)。

摘　　要：分别采用超滤离心管和超滤杯两种方式制备不同分子量的溶解性有机物(DOM),探究不同的分子量分级方式对获得的DOM组成成分特征及其生物毒性效应的影响,同时判明各组分联合作用方式.DOM分别来源于城市污水厂出水(EfOM)及商品天然腐植酸(SWR-NOM).结果表明,两种分级方式获得的不同分子量DOM含有相同的荧光峰,腐殖酸类物质是EfOM与SWR-NOM含有的主要荧光类有机质(FDOM),占FDOM的56%~91%.同种DOM不同分子量组分中FDOM组成相对含量一致.采用超滤离心管分级得到的DOM在不同分子量区间内SUVA254和E2/E3的差异较大,而采用超滤杯分级时差异变化较小.对于发光细菌急性毒性,在同一分子量区间内,采用超滤杯分级获得的DOM组分检测到的发光细菌毒性值大于采用超滤离心管分级检测到的结果,但采用超滤杯分级时<1kDa组分的急性毒性效应值低于检测限.利用浓度加和模型(CA)对DOM中各组分的联合作用方式进行判断,发现DOM混合物的联合毒性符合CA模型,预测联合毒性效应占检测到的实际水样毒性的67%~104%.Dissolved organic matter(DOM)fractions with different molecular weights were prepared by ultrafiltration centrifuge tube and ultrafiltration cup,respectively.Under the two different DOM molecular weight fractionation methods,the characteristics of obtained fractions and their biotoxicity were explored,and their joint action mode were identified.DOM were obtained from municipal wastewater treatment plant effluent(defined as EfOM)and commercial natural humic acid(defined as SWR-NOM).The results showed that DOM fractions with different molecular weight obtained from the two fractionation methods had the same fluorescence peak.Humic-like substances were the main fluorescent dissolved organic matter(FDOM)in EfOM and SWR-NOM,accounting for 56%~91%of FDOM.For the same DOM,the relative content of FDOM composition in different molecular weight components is basically consistent.The variation of SUVA254 and E2/E3 from different fractions obtained by ultrafiltration centrifuge tube was larger than that by ultrafiltration cup.For the luminescent bacteria acute toxicity,in the same molecular weight range,the luminescent bacteria toxicity value of DOM fractions obtained by ultrafiltration cup fractionation method was higher than that detected by ultrafiltration centrifuge tube fractionation method,but the acute toxicity of<1KDa fraction obtained from ultrafiltration cup fractionation method was lower than the limit of detection.Using the concentration addition model(CA)to judge the mode of joint action for each fraction in DOM,it was found that the joint toxicity of DOM mixture conforms to the CA model,and the predicted joint toxicity values account for 67%~104%of detected toxicity value.

关 键 词：溶解性有机物(DOM) 分子量分级 生物毒性 浓度加和模型 

分 类 号：X171[环境科学与工程—环境科学]