太湖水体溶解态腐殖质的结构组成及环境效应初探

发布时间：2018-03-23 08:39

本文选题：溶解腐殖质　切入点：富营养化　出处：《华东师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：溶解有机物(Dissolved Organic Matter,DOM)是天然水体中的重要组成部分,可以与水体中的重金属相互作用,影响水体中微量金属离子的形态、毒性、迁移转化过程及生物有效性,在水域生态系统的生物地球化学循环过程中发挥着重要的作用。湖泊在天然水体中处于重要地位,在富营养化湖泊中水华过程产生大量的有机质,是水体中有机质的主要来源之一,为金属离子的络合提供了更多的结合位点。在微生物的改造作用下,DOM结构组成发生改变,进一步影响了其环境行为。此外,DOM可转化为生物可利用性营养盐,是湖泊内源性可溶营养物释放的重要一环,对水华的发生和持续时间具有重要的影响。腐殖质(Humic Substances,HSs)作为DOM的主要组分(约占40%-80%),是天然水体中与金属离子相互作用的主体。HSs的结构组成及在水体中的转化过程是影响DOM地球化学行为的重要因素。因此,对水华过程中HSs结构组成及其与金属离子反应性质的认识,对深入认识富营养化水体中DOM的生物地球化学行为及环境效应具有重要的意义。本文选取典型的富营养化湖泊一太湖为研究对象,采用国际腐殖质协会推荐的方法,对太湖非水华期及水华期表层水体中溶解态腐殖质(Dissolved HS,DHS)进行了提取和分离,并利用元素分析、傅立叶变换红外光谱、核磁共振、热重分析及荧光光谱等表征手段对DHS不同组分进行表征。在此基础上,利用二维相关红外光谱分析和表征了非水华期及水华期的DHS中不同官能团金属离子络合能力的差异。初步结论如下:1.腐殖酸(Humic acids,HAs)和富里酸(Fulvic acids,FAs)均含有较高的碳和氧含量(37%-56%);与FAs相比,HAs中含有更多的含氮组分(6.4%vs.3.0%)。非水华及水华期DHS中均含有三类荧光组分。脂肪族结构是FAs的主要组成部分,芳香族结构是HAs的主要组成部分。水华期的DHS比非水华期的DHS具有更多的含氮官能团(5.3%vs.4.2%),与水华过程密切相关。与非水华期的DHS相比,水华期的DHS含有更多新鲜物质,具有更多的羧基和酚羟基官能团(32.8%vs.29.3%),提供了更多的结合位点。2.非水华期FAs与水华期FAs中的含氮及含氧的官能团在与Cu(Ⅱ)反应过程中具有更好的亲和能力。非水华期FAs官能团的亲和顺序为酰胺Ⅰ的C=O酰胺Ⅱ的N-H变形和C=N伸缩多糖中的C-O伸缩木质素中芳香基团的C-HCOO-不对称伸缩酚羟基中的C-O伸缩及O-H变形酚羟基中的O-H伸缩羧基中的C=O伸缩。而水华期FAs中有机官能团与Cu(Ⅱ)的亲和顺序可推测为羧基中的C=O酰胺中的C=O酚羟基中的C-O蛋白质中的酰胺11多糖中的C-O脂肪族C-OH酚羟基中的O-H芳香基中的C-H。非水华期FAs中含氮有机物在与Cu(Ⅱ)反应过程中具有更快的亲和顺序,水华期FAs中的羧酸对Cu(Ⅱ)浓度变化最为敏感。水华过程中蓝藻分泌的胞外高聚物(Extracellular polymer substances,EPS)含有较多的碳水化合物(30%),改变了水华期FAs的组成,这可能是非水华期和水华期FAs亲和顺序差异的原因。3.非水华期及水华期水体中细菌的群落组成存在较大差异。β变形菌在非水华期的相对丰度约是水华期的4倍,而α变形菌水华期的含量约是非水华期的8.5倍。非水华期及水华期的Fluviicola(0.02%vs.6.4%)、SAR 11(1%vs.28.8%)、hgcI(6.7%vs.19.8%)属含量的差异改变了 DHS中含氮化合物及多糖等的含量和结构,进而影响了非水华期和水华期FAs中不同官能团与Cu(Ⅱ)的亲和顺序。
[Abstract]:Dissolved organic matter (Dissolved Organic, Matter, DOM) is an important part in natural water, can interact with heavy metals in water, effects of trace metal ions in water morphology, toxicity and bioavailability, process migration and transformation, plays an important role in the biogeochemical cycle of aquatic ecosystem. The lake is in the important position in natural waters, in eutrophic lakes bloom process produces large amounts of organic matter, is one of the main sources of organic matter in water, provide more binding sites for complexation of metal ions. In the transformation of microorganism, DOM structure change, further influence its environmental behavior. In addition, DOM can be transformed into bio available nutrient, nutrient release of endogenous soluble lakes are an important part of the occurrence and duration of water bloom has important influence Ring. (Humic Substances, HSs humus) as the main component of DOM (about 40%-80%), is a structure composed of natural water and metal ion interactions of main body of.HSs and transformation process in water is an important factor affecting DOM geochemical behavior. Therefore, understanding of the structure of HSs and its composition in the process of water bloom reaction of metal ions with nature, has important implications for biogeochemical behavior and environmental effects of understanding in eutrophic water DOM. This paper selects a typical eutrophic lake in Taihu as the research object, using the international humic matter Association recommended method of dissolved in surface water of Taihu non bloom period and bloom in the period of humus (Dissolved HS DHS) was extracted and separated, and by elemental analysis, Fu Liye transform infrared spectroscopy, NMR spectroscopy, thermogravimetric analysis and fluorescence spectra of DHS in different components Respectively. On this basis, using two-dimensional correlation infrared spectroscopy analysis and characterization of the difference between the non bloom period and bloom period DHS in different functional groups of metal ion complexing ability. The preliminary conclusions are as follows: 1. humic acids (Humic acids, HAs) and fulvic acid (Fulvic, acids, FAs) the carbon content and oxygen content with high the (37%-56%); compared with FAs, HAs contained more nitrogen components (6.4%vs.3.0%) and DHS. The non bloom bloom contained three kinds of fluorescent components. The structure of FAs is mainly composed of aliphatic, aromatic structure is the main component of HAs. During the blooms of DHS than the non bloom period DHS has more nitrogen functional groups (5.3%vs.4.2%), is closely related with the bloom process. Compared with the non bloom period DHS, bloom period DHS contains more fresh material, with more carboxyl and phenolic hydroxyl groups (32.8%vs.29.3%), and the binding sites of.2. more The non bloom period FAs with bloom period FAs in nitrogen and oxygen containing functional groups with Cu (II) has a better affinity reaction process. C-O O-H C-HCOO- expansion and asymmetric stretching of phenolic hydroxyl affinity sequence FAs functional groups for non bloom C=O amide amide II of the N-H and C=N stretching C-O stretching deformation wood in the polysaccharides of Fang Xiangji group in the C=O stretching O-H stretching deformation in the carboxyl phenolic hydroxyl and FAs. During the blooms of organic functional groups and Cu (II) affinity sequence can be presumed O-H aryl C-O protein C=O C=O amide carboxyl phenolic hydroxyl in the amide more than 11 sugar in C-O aliphatic C-OH phenolic hydroxyl C-H. in the non bloom period in FAs organic compounds containing nitrogen and Cu (II) in the reaction process with affinity sequence faster, FAs in the bloom of Cu acid (II) concentrations was most sensitive. In the process of cellular secretion of cyanobacteria bloom The outer polymer (Extracellular polymer substances, EPS) contain more carbohydrates (30%), changed the composition of phytoplankton bloom period FAs, this may be the reason of the non bloom period.3. and FAs affinity sequence differences during the blooms of non community of bacteria in water bloom and bloom period. There is a big difference. The relative abundance of non beta Proteobacteria the bloom period is about 4 times the bloom period, bloom period and alpha content in deformation is about 8.5 times the non bloom period. Non bloom period and bloom period Fluviicola (0.02%vs.6.4%), SAR 11 (1%vs.28.8%), hgcI (6.7%vs.19.8%) is the change of the content of the differences between the content and structure of nitrogenous compounds and polysaccharides in DHS, the influence of different functional groups of Cu and non bloom period and bloom period in FAs (II) affinity sequence.

【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X524

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