铜绿微囊藻有机物氯化消毒副产物的形成及去除机理研究

发布时间：2018-04-18 10:27

本文选题：藻类有机质 + 含碳消毒副产物　；参考：《天津大学》2014年硕士论文

【摘要】：藻类有机物成为了饮用水氯化过程中有害消毒副产物(DBPs)的重要前体物,但是藻类有机物生成消毒副产物的特点研究仍很有限。本文选取典型蓝藻-铜绿微囊藻为代表,研究了藻类有机物(algal organic matter,AOM)的性质特征,不同氯化条件(氯投加量、接触时间、pH值和溴离子浓度)对AOM生成含碳消毒副产物和含氮消毒副产物的影响,最后探讨了混凝和活性炭吸附对AOM的去除效果和对DBPs的消减情况。研究发现AOM具有高亲水性、低分子量、低芳香性等特点。AOM包括胞内有机质和胞外有机质。胞内有机质的有机氮和有机碳比例为(TON/TOC)为0.102,三维荧光图谱表明其含有叶绿素a、藻蓝蛋白、芳香族蛋白和类腐殖酸物质。胞外有机质TON/TOC为0.074,三维荧光图谱表明其含有类腐殖酸物质。氯消毒过程中,胞内有机质和胞外有机质产生的卤代甲烷和卤代乙腈种类相似,浓度接近。pH值升高使胞内有机质和胞外有机质生成的三氯甲烷浓度升高,二氯乙腈浓度降低。和胞内有机质相比,胞外有机质产生的三卤甲烷和卤代乙腈的状况更容易受pH值和溴离子浓度影响。无溴离子时,三氯甲烷随反应时间延长浓度升高,而二氯乙腈、三氯乙腈、1,1-二氯丙酮和1,1,1-三氯丙酮浓度升高到某值后会下降。pH值升高会使三氯甲烷的生成量增大,其他类型DBPs的生成量减小。DBPs的浓度随氯投加量提高而增加。存在溴离子时,卤代甲烷的总量在pH值为7.5时最高,溴取代因子在pH值为8.5时最高。提高氯投加量会提高卤代甲烷和二卤乙腈总量,三卤甲烷的种类分布无明显变化,二卤乙腈的溴取代因子降低。溴离子浓度升高,三卤甲烷和二卤乙腈总量升高,三卤甲烷从氯代产物过渡到溴代产物。AOM在混凝沉淀中难于形成大的矾花,沉淀性能较差。对于初始DOC为2.9~3.9mg/L的藻溶液,聚合氯化铝投加量为15~25mg/L(r1=100r/min,t1=30s)时,DOC能降低47%~52%。混凝对不同的DBPs的控制能力有较大区别。活性炭对AOM的去除能力有限,在活性炭投加量为10~30mg/L,吸附时间为10~30min时,AOM的DOC去除率在12%~32%,三氯甲烷去除率为15%~25%,二氯乙腈去除率为15%~70%。
[Abstract]:Algal organic matter has become an important precursor of harmful disinfection by-product (DBPs) in chlorination of drinking water, but the characteristics of algal organic matter producing disinfection by-product are still very limited.In this paper, typical cyanobacteria-microcystis aeruginosa were selected as representatives to study the characteristics of algal organic matterfly (AOM) and the chlorination conditions (chlorine dosage).The effects of contact time pH value and bromine ion concentration on the formation of carbon-containing disinfection by-products and nitrogen-containing disinfection by-products from AOM were discussed. Finally, the removal efficiency of AOM and the reduction of DBPs by coagulation and activated carbon adsorption were discussed.It was found that AOM has high hydrophilicity, low molecular weight and low aromaticity. AOM includes intracellular organic matter and extracellular organic matter.The organic nitrogen and organic carbon ratio of intracellular organic matter was 0.102. The three dimensional fluorescence spectra showed that it contained chlorophyll a, phycocyanin, aromatic protein and humic acid.The TON/TOC of extracellular organic matter was 0.074. The three dimensional fluorescence spectra showed that it contained humic acid-like substances.In the process of chlorine disinfection, halogenated methane and halogenated acetonitrile produced by intracellular organic matter and extracellular organic matter were similar. The concentration of trichloromethane in intracellular organic matter and extracellular organic matter increased and the concentration of dichloroacetonitrile decreased when the concentration was close to pH value.Compared with intracellular organic matter, trihalomethane and halogenated acetonitrile produced by extracellular organic matter were more susceptible to pH value and bromine ion concentration.When there is no bromine ion, the concentration of trichloromethane increases with the prolongation of reaction time, while the concentration of dichloroacetonitrile, trichloroacetonitrile, trichloroacetone and trichloroacetone increases to a certain value. The increase of pH value increases the production of trichloromethane.The concentration of other types of DBPs decreased with the increase of chlorine dosage.In the presence of bromine ions, the total amount of halogenated methane was the highest at pH 7.5, and the bromine substitution factor was highest at pH 8.5.The total amount of halogenated methane and dihaloacetonitrile was increased by increasing the amount of chlorine, but the species distribution of trihalomethane did not change obviously, and the bromine substitution factor of dihaloacetonitrile decreased.With the increase of bromine ion concentration, the total amount of trihalomethane and dihaloacetonitrile increased, and the transition of trihalomethane from chlorinated product to brominated product. AOM was difficult to form large alum flower in coagulation precipitation, and the precipitation performance was poor.For algae solution whose initial DOC was 2.9~3.9mg/L, the amount of polyaluminium chloride was 15 ~ 25 mg / L ~ (-1) / L ~ (-1) ~ (-1) ~ (-1) 路min ~ (-1) ~ (-1)).The control ability of coagulation to different DBPs is different.The removal ability of activated carbon to AOM is limited. When the amount of activated carbon is 10 ~ 30mg / L, the removal rate of DOC is 1232 / L when the adsorption time is 10~30min, the removal rate of trichloromethane is 15 / 25g / L, and the removal rate of dichloroacetonitrile is 15 / 70g / L.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU991.2

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