GAC/H_2O_2对二级出水溶解性有机物的降解研究

颗粒活性炭(GAC)常用作吸附剂,其催化作用未受到重视。为此研究了GAC催化H2O2氧化(GAC/H2O2)体系对生活污水处理厂二级出水中溶解性有机物的降解效果。结果表明,GAC/H2O2对二级出水COD和UV254去除率明显高于GAC和H2O2单独作用。不同性质的GAC其吸附与催化能力不同;随H2O2投加量增加去除率先增加后降低;降解率随GAC投加量增加而增加;pH在2~10均能实现有机物的降解。对比反应前后溶解性有机物的分子量及亲疏水性分布,发现二级出水中溶解性有机物的成分可能是影响反应效果的一个因素。GAC/H2O2体系常温常压下自发进行,无污泥产生,值得进一步深入研究。     

二级出水中溶解性有机物对超滤膜污染的影响

利用XAD-8/XAD-4树脂将污水处理厂二级出水中的溶解性有机物(DOM)分为疏水性有机酸(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),研究其对PVDF超滤膜污染性能的影响.结果表明,二级出水中DOM对超滤膜污染的顺序为疏水性有机物＞过渡性亲水性有机物＞亲水性有机物.二级出水的五种组分中,重均分子量(Mw)呈现出HPO-A＞TPI-A＞HPO-N＞ HPI＞TPI-N的趋势,说明分子量大小与膜污染成正比.有机物对膜的污染程度和膜对有机物的去除率相关性不大.反洗对超滤膜去除有机污染的效果良好,特别是NaOH+NaClO的混合反洗水对有机污染物的去除效果最好,能够使膜的比通量恢复率达到58％.     

赣江南昌段原水溶解性有机物分子量特性研究

利用膜过滤法对赣江南昌段原水溶解性有机物分子量进行了连续13个月测定,对原水中溶解性有机物季节性含量变化规律及溶解性有机物在各个分子量区间的分布特性进行了研究分析.结果表明,赣江南昌段原水溶解性有机物UV254紫外分光光度值主要介于0.03～0.06cm-1之间,水体中溶解性有机物在3～8月含量较高,与流域降雨携带面源污染关系密切,与降雨量呈正相关;赣江南昌段原水溶解性有机物以小分子和大分子为主,与大多数水体相同;同时还发现,3～6月水体中小于1k道尔顿的溶解性有机物含量较高,水厂需注意控制消毒副产物的产生,6～8月大于30k道尔顿的溶解性有机物含量占优,其它区间溶解性有机物含量较低且稳定.     

臭氧氧化对地表水溶解性有机物去除效果的影响研究

针对臭氧氧化作用对受污染地表水中溶解性有机物去除效果的影响进行研究。结果表明:臭氧投加比低于1mgO3/mgDOC时,臭氧对UVA、CODCr和UV410等有机物去除效率较高;臭氧投加比例为0.7mgO3/mgDOC时,BOD/COD由7.4%提高至18.4%,比紫外消光度(SUVA)逐渐降低并趋于平缓;不同臭氧投加比例下水中溶解性有机物的三维荧光指纹光谱变化规律表明,受污染地表水DOM中主要荧光物质为芳香族蛋白质(荧光峰A、B和C)及类腐殖酸(荧光峰D),其中,A峰、B峰和C峰的中心位置分别位于225/300nm、225/338nm和275/342nm;臭氧投加比例为0.7mgO3/mgDOC时峰强削减率为64%～81%,同时部分芳香族蛋白质的结构也发生了变化。     

阳澄湖原水中溶解性有机物去除规律研究

考察原水—预臭氧—混凝沉淀—砂滤—后臭氧—生物活性炭—氯消毒工艺对阳澄湖原水中溶解性有机物(Dissolved organic matter,DOM)的去除规律,结果表明阳澄湖原水溶解性有机碳(Dissolved organic carbon,DOC)与紫外吸光度UV254总体呈现夏季高、冬季低的特征,随着原水DOC与UV254的降低,各工艺单元对DOC与UV254的去除率也逐渐降低,去除率分别在29.2％?44.3％与55.4％?66.5％.对UV254的去除优于DOC,常规处理工艺优于深度处理工艺,对大分子的去除优于小分子.平行因子分析法(Parallel factor analysis,PARAFAC)分析三维荧光光谱确定阳澄湖水样DOM由4组分构成,类蛋白类色氨酸C1、类酪氨酸C2、氨基酸或蛋白质C4,以及类腐殖质紫外区类富里酸C3.该工艺流程对C2、C3、C4去除率总体呈现上升趋势,达到30.1％、70.7％和43.4％.     

地下水中溶解性有机物吸收光谱模型的对比研究

以往对于溶解性有机物(DOM)吸收光谱的研究主要集中在地表水体,为了了解地下水样品的光吸收特性、探索能够方便有效地表征地下水中DOM光吸收性质的理想模型,收集了某河湖相沉积的含水层中62个地下水样品的DOM吸收光谱,对线性指数模型、非线性指数模型、加背景项指数模型和幂函数模型等四种光吸收模型进行了拟合和对比分析。统计检验发现,传统的线性指数模型拟合效果不如其它三种模型好;幂函数模型的精度和实用性相比最佳,平均决定系数为0.991 8,在250～450nm光谱范围内拟合DOM吸收光谱斜率为(5.93±0.40)nm-1。幂函数模型为DOM化学性质及组分信息与模型参数之间的关系的研究提供了一种可行有效的方法。另外,还建立了更为一般的吸收光谱的幂函数模型,以期对地下水DOM快速分析和野外地下水现场调查起到积极作用。     

长江常熟段水溶解性有机物分子质量分布特性

采用超滤膜法对水溶解性有机物进行物理分级,研究长江常熟段水源水中不同分子质量区间DOC和UV254分布的变化特征及其原因。结果表明,长江常熟段水源水总体水质较好,高锰酸盐指数、氨氮、总磷等指标均未超过地表Ⅲ类水体水质标准,符合饮用水源地卫生要求。2008年11月至2009年9月期间,水源水中分子质量小于1kDa的DOC所占比例平均为64.3%,分子质量小于1kDa的UV254所占比例平均为45.2%,表明长江水源水中水溶解性有机物主要以小分子质量的有机物为主,汛期水源水中分子质量在3～10 kDa区间的DOC和UV254比例较枯水期有显著提高。     

改性沸石去除水中有机物特性的研究

沸石是多孔的吸附材料，它的吸附性能与被吸附物质的大小有很大的关系。研究改性沸石去除水中有机物的特性，结果表明：当水中投加足量的沸石时，改性沸石同样能去除水中的有机物；改性沸石主要去除大分子量的有机物，对小分子量的有机物去除效果很差；沸石对原水中有机物的去除率比配水实验低；改性沸石对UV254的去除率比对DOC的去除率高。     

水源水中溶解性有机物相对分子质量分布及工艺选择

以珠海地区部分水源水为研究对象,采用超滤分离方法将其中的有机物分成相对分子质量不同的几种形态,考察了各相对分子质量组分在TOC、UV254方面的差异。结果表明:①溶解性有机物在不同相对分子质量区间的分布反映了各水源的水质特征;②珠海的水源中河流地表水的溶解性有机物以相对分子质量小于500的小分子有机物和大于10000的大分子有机物为主,而水库地表水中的溶解性有机物则以相对分子质量3000～10000的中分子有机物为主;③珠海水源水中有机物含量较低,采用混凝沉淀的传统水处理工艺即能达到良好的出水效果,不必增加其他工艺。在水源水质恶化的突发情况下,可采用预氧化、投加粉末活性炭等方法来加以控制。     

有机物相对分子质量分布对O3-GAC工艺中臭氧投加量的影响

采用滤膜法测试了不同臭氧投加量下,臭氧活性炭出水中的有机物相对分子质量分布的特性,并对其去除情况进行了分析.结果表明,相对分子质量小于1 000的有机物易被臭氧氧化为C02和H2O而去除.大于10 000的大分子有机物被氧化分解为3 000～10 000的小分子有机物,这部分小分子有机物可被后续活性炭生物降解去除.增加臭氧投加量,大于30 000的有机物被氧化为相对分子质量分布范围更广的小分子有机物,使大于30 000的有机物易被活性炭降解,但会使小于1 000的有机物的去除效果降低.臭氧投加量的确定应考虑水中有机物相对分子质量分布情况.     

富营养化湛江港湾有色溶解有机物光学特性的时空变化分析

有色溶解有机物(CDOM)是海洋水色遥感三要素之一,近海二类水体CDOM的遥感监测一直是国内外研究的热点和难点。基于2016-2017年湛江港湾两个航次的调查资料,探讨了湛江湾水体中CDOM光学特性的时空变化特征及溯源问题。结果表明:在季节变化方面,港湾内表层水体CDOM吸收系数ag(355)和光谱斜率S275~295呈现出秋季夏季的变化特征。在空间分布方面,夏季港湾内表层和底层的ag(355)则基本呈现由北向南、由西向东递减的趋势,表层和底层CDOM光谱斜率S275~295在水平空间上大致呈现斑块状的分布;同时,湾内叶绿素a浓度和浊度均较高,叶绿素a浓度在1~5μg/L之间变化,浊度的范围是5~70 NTU,溶解氧的浓度较小,在3~5 ml/L之间变化。对CDOM吸收系数ag(355)与光谱斜率、叶绿素a、溶解氧、浊度的关系深入分析发现,夏季和秋季水体中CDOM来源主要有浮游植物现场生产和陆源所携带,同时底层沉积物的再悬浮也是秋季水体中CDOM来源之一。两个季节CDOM浓度与DO负相关性较好,表明它对水体的污染和富营养化具有一定的指示作用。     

Fluorescence analysis of dissolved organic matter in natural,waste and polluted waters—a review

Dissolved organic matter (DOM) in aquatic systems originates from a range of sources. Some is allochthonous, transported from the surrounding landscape to the water body, and is derived from and influenced by the geology, land use and hydrology of its origin. Some is created in situ through microbial activity, which may provide an independent source of organic matter, or a recycling mechanism for that which has been transported into the water body. The relative contribution of each source depends upon the location and environmental conditions within and without the water body. Human activity is also a source of DOM, much of which is believed to be labile, which can enter the aquatic system through direct point discharges, diffuse leaching and aerial dispersal. Fluorescence spectroscopy can provide an excellent tool to source DOM fractions, and to monitor and understand DOM transformations in aquatic systems, as much DOM has an intrinsic fluorescence. In particular, recent advances in optical technology, enabling rapid investigation of shorter wavelengths, have enabled more detailed characterization of organic material and its reactions in water. In this article, we review the use of fluorescence spectroscopic techniques to measure the intrinsic fluorescence of organic matter and the application of fluorescent DOM analysis in marine waters, freshwaters and wastewaters. Copyright © 2007 John Wiley & Sons, Ltd.     

溶解性有机质对低影响开发设施运行影响的研究进展

低影响开发(LID)设施在治理城市内涝和径流污染中发挥重要作用，在我国海绵城市建设中应用广泛。溶解性有机质(DOM)是一类具有较强的吸附、络合作用的溶解态物质，其质量占比高达径流污染物的50%以上。为阐明DOM对LID设施运行的影响，结合国内外研究现状及进展，综述DOM自身性质及其对LID设施中重金属(HMs)、持久性有机物(POPs)的归趋以及对微生物环境的影响，指出DOM会通过吸附、络合与HMs、POPs作用，造成LID设施填料吸附位点饱和、填料堵塞、微生物相对丰度(RAs)改变等。本研究旨在为LID设施设计和运行优化提供参考。     

周村水库大气湿沉降氮磷及溶解性有机物特征

为揭示周村水库大气湿沉降中污染物的污染特征,通过收集周村水库2016年3月至2017年2月大气湿沉降样品,测定了大气湿沉降中氮磷以及溶解性有机物的质量浓度,分析了污染物的污染特征及大气湿沉降量的变化规律。结果表明:周村水库的降水主要集中在夏秋季,占全年的68.50%;降水中总氮质量浓度在1.67~7.63 mg/L之间,氨氮和硝氮是其主要组分,分别占总氮的52.91%和28.49%;降水中的硝氮和氨氮年湿沉降通量分别为772.45mg/m^2和1411.99 mg/m^2,且与降水量呈显著正相关关系(P<0.01);单因子水质评价法和综合污染指数法评价得出大气湿沉降中的降水大多为劣Ⅴ类的重度污染水体;总磷和有机物的湿沉降通量最大值出现在夏季,与降水量也呈显著正相关关系(P<0.01);大气湿沉降中的溶解性有机物以富里酸为主,呈现较强的自生源特征。     

水处理工艺过程中有机物分子量分布规律

针对太湖流域某湖泊水源有机物分子量分布的特性,考察饮用水处理各工艺单元对有机物的去除效应。结果表明:原水以小分子量有机物为主,小于1k Dalton的有机物占36.1%;常规工艺对大分子量有机物去除率高,尤其对分子量在10k Dalton以上的有机物去除率达32.7%以上,但对小分子量有机物去除率低,其中分子量小于1k Dalton的有机物反而增加了12.6%左右。超滤深度处理工艺中PES膜工艺对小分子量有机物,特别是分子量小于10kDalton的有机物去除率达76.4%,出水UV254值及SUVA值比砂滤出水分别下降了22.0%和11.2%;PVDF膜工艺对各分子量有机物均有较好的去除,但对大分子有机物去除效果优于小分子有机物,其出水UV254值及SUVA值比砂滤出水分别下降了28.8%和6.3%。     

Landscape integration of North Patagonian mountain lakes: a first approach using characterization of dissolved organic matter

North‐western Patagonia contains a variety of glacially formed mountain lakes located at different positions from the treeline in the Andean Patagonian forest region. Water chemistry of six North Patagonian lakes located in an altitudinal gradient, above, at and below the treeline (~41°S) were analysed in this study. The relative importance of allochtonous to autochthonous carbon inputs along a marked catchment vegetation gradient encompassing altoandino vegetation and Nothofagus forests was addressed. The dissolved organic carbon (DOC) concentration varied among the study lakes, with the lakes located higher in the landscape exhibiting lower DOC concentrations (<1 mg L^?1) than lakes located at or below the treeline (>2 mg L^?1). Analysis of coloured and fluorescent dissolved organic matter (CDOM and FDOM, respectively) followed the DOC pattern, despite the contrasting catchments of the study lakes. The results indicated the CDOM in all the lakes had low molecular weight and low aromaticity. The excitation–emission matrices (EEMs) highlighted three distinctive fluorophores in the FDOM, including two humic‐like (peak A and peak C) revealing the presence of humic terrestrial material, and a protein‐like fluorophore (peak T) generally associated with autochthonous DOM. The increased intensities of the humic fluorophores in the lakes located below the treeline suggest higher allochtonous carbon inputs from their catchments. This evidence collectively suggests that mountain lakes exhibit some heterogeneity in terms of DOM, likely attributable to their position in relation to the treeline, which determines the contribution of the catchment. As remote lakes are extremely sensitive to changes in their catchments, these North Patagonian mountain lakes may accurately track the impact of climate and anthropogenic changes on the landscape.     

荧光光谱技术在废水溶解有机物研究中的应用进展

分析废水中特征污染物质的组成、性质、来源等对于水污染控制、应急事故处理、环境质量责任认定等具有重要的意义和价值。荧光光谱技术利用物质的荧光特性,构建物质的特征光谱图,并以此分析物质特性,可用于分析废水中腐殖质、氨基酸、荧光增白剂、木质素、多环芳烃等多种有机污染物质。文章从荧光光谱技术的原理出发,主要对三维荧光光谱技术和同步荧光光谱技术在研究废水溶解有机物特征组成物质中的应用及环境因子对其影响进行了综述,并对该技术的发展前景进行展望,以期为废水溶解有机物特征组成物质提供完善可靠的分析方法。     

Seasonal changes predominant over manure application in driving dissolved organic matter shifts in agricultural runoff

Non-point source nutrient pollution can cause eutrophication, hypoxic events, and harmful algal blooms in surface waters. Surface water eutrophication is frequently attributed to agricultural runoff, a known source of inorganic and organic nutrients to surface and subsurface waters. Analysis of dissolved organic matter (DOM) using ultrahigh resolution mass spectrometry is an effective tool for characterizing diverse organic nitrogen and phosphorus components of DOM that may be mineralized and/or assimilated and ultimately contribute to eutrophication. An anion exchange resin was applied to extract DOM from surface and subsurface tile runoff from agricultural plots located within the Maumee River watershed (Ohio, USA) that received raw liquid manure, polymer-treated dewatered manure, or no manure (control). DOM extracts were analyzed using Fourier transform ion cyclotron resonance mass spectrometry prior to manure application and during three runoff events after manure application. Organic nitrogen compounds were predominant, making up 38–48% of the total assigned formulas. Principle coordinates analysis indicated clustering predominately by sample month and secondarily by treatment. These findings show that a large amount of variability in DOM in runoff was observed regardless of manure application, indicating the important role played by natural processes in driving transformation of the DOM pool during the growing season. Molecular ions unique to runoff from manure-applied plots were also identified that may be useful in source-tracking of non-point source nutrient pollution in waters draining to Lake Erie.