【作者】 吴明松；

【导师】 田禹； 黄君礼；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2011， 博士

【摘要】 随工农业生产的发展越来越多的水体遭受着更为严重的污染,给饮用水安全带来了威胁,同时随着生活水平的提高,人们对水质也提出了越来越高的要求。微囊藻毒素（MCs）与隐孢子虫卵囊即是近年倍受关注的两种污染物。二氧化氯（ClO₂）因高效、广谱、安全等优点已成为水消毒领域中氯系消毒剂的理想替代产品,但在消毒过程中生成的副产物亚氯酸盐也令人担忧。本文通过酶联免疫吸附法、液相色谱-质谱、活性染色等检测方法和量子化学手段,对ClO₂去除水中微囊藻毒素及隐孢子虫卵囊的效果、影响因素及机理进行了研究,同时模拟实际水处理工艺研究了ClO₂预氧化及混凝、沉淀、过滤和消毒各单元及整个工艺流程对含藻水的去除效果。此外采用三代大鼠毒理试验方案应用行为学观察及病理解剖手段对ClO₂在消毒过程中最主要的副产物——亚氯酸盐的长期神经发育毒性进行了考察。论文获得了一系列具有创新意义的成果。研究了饮用水处理工艺中ClO₂对较低浓度微囊藻毒素（MCs）的去除特性,揭示了MCs与ClO₂反应的机理和反应产物。证实了ClO₂对于微囊藻毒素MC-LR、MC-RR和MC-YR具有良好的去除效果,去除规律相似,去除的容易程度为MC-RR>MC-YR>MC-LR,去除效果受ClO₂浓度、反应时间影响很大,受pH值和反应温度影响不显著。确定了反应过程中,MCs结构中Adda基团两端的碳原子被羟基自由基攻击,最终生成各自的二羟基取代物。全面考察了常规饮用水处理工艺中对含藻水的去除效果,提出了含藻原水的ClO₂强化预氧化解决方案。证实了在常规工艺中,混凝沉淀工艺单元除藻效果较好,但对含MCs的去除极其有限,处理效果的主要影响因素是混凝剂投量,其次是沉淀时间和慢搅转速。过滤工艺中无烟煤所占比例越高的滤池,出水水质越好。消毒工艺中,滤前投加ClO₂有利于高锰酸盐指数、浊度等指标的去除,且出水中亚氯酸盐的含量更低,但滤后投加ClO₂对MCs的去除率较高。模拟工艺证明:对于典型含藻原水,采用2.5 mg/L ClO₂预氧化40 min,然后投加聚合氯化铝铁20 mg/L混凝,60 r/min慢搅20 min后,沉淀30 min,再投加0.8 mg/L ClO₂,最后经无烟煤:石英砂为2:1的滤池以10 m/h的滤速过滤,处理效果优异。研究了ClO₂对隐孢子虫卵囊的杀灭特性,证实了ClO₂可以有效地杀灭隐孢子虫卵囊,主要的影响因素是反应时间,ClO₂投量和反应温度,如果水中存在较高的浊度和高锰酸盐指数,则隐孢子虫卵囊的杀灭效果会有所下降。同时发现ClO₂在灭活隐孢子卵囊的过程中表现出很强穿透力和渗透性,可在不破坏卵囊外部整体性的情况下将其灭活,研究并提出了亚氯酸盐的长期神经毒理学效应,发现连续三代摄入高浓度的亚氯酸盐可引起第二代、第三代个别仔鼠小脑产生病变,影响运动能力,还可能会对学习、记忆能力造成影响。确定了对于Wistar大鼠运动神经发育的无明显副作用剂量为30 mg/L。本文所得出的研究结果不仅为ClO₂控制水中的MCs和隐孢子虫卵囊提供了理论依据,也为含藻水的处理提出了可行的ClO₂预处理方案,具有重要的理论意义与应用价值。此外推进了亚氯酸盐的毒理学研究,可为扩大ClO₂的应用及标准的制定提供参考。更多还原

【Abstract】 Along with the development of agriculture and industry, water body has been suffered serious pulution that threatened the water safety. People also demand higher quality water followed by the improvement of the living standard. Microcystins (MCs) and Cryptosporidium are of great concern under this background. Chlorine dioxide has been considered as an ideal substitution of chlorine in potable water treatment, however chlorite produced in the disinfection process has been an issue.Enzyme-linked immunosorbent assay, HPLC-MS/MS method, intravital staining and quantum chemistry method were used to invesgated the efficiency, influence factors and reaction mechanism of chlorine dixoide removing microcystins and Cryptosporidium oocysts in water. Treatment efficiencies of chlorine dioxide proixidation, coagulation, sedimentation, filtration and disinfection on algae-laden water were studied by simulative processes. In addition, the neurotoxicity of chlorite in prolonged exposure was preliminarily investigated by the methods of ethology and neuroanatomy assay in three generation rat pups. A series of original conclusions were drawn through this thesis.Performance of chlorine dioxide removing MCs were studied. And the recction mechanism and products between MCs and chlorine dioxide were also determined. The results showed that chlorine dioxdide can degrade MC-LR, MC-RR and MC-YR effectively. The reactions follow similar pattern and affected greatly by chlorine dioxide concertration and reaction time while slightly by pH and temperature. In the reactions, carbon atoms at the end of Adda groups were attacted, and then Adda groups were oxidated followed by dihydroxy substituendums formated.Treatment effect of algea-laden water by conventional drinking water treatment processes was investigated in the general. It was found that coagulation and sedimentation can hardly remove microcystins but can remove large amount of algae. The filter contained higher ratio of blind coal resulted in better effluent. In the disinfection process, more microcystins can be removed by adding chlorine dioxide before filtration than after. However, higher removal rates of potassium permanganate index and turbidity and lower chlorite formation can be abtained when adding chlorine dioxide after filtration. Satisfactory water quality can be gotten at the condition that: proxidation by 2.5 mg/L chlorine dioxide for 40 min, coagulation at 60 r/min for 20 min, sedimentation for 30 min,addition 0.8 mg/L chlorine dioxide for disinfection and then filtration at 10 m/L with the ratio of blind coal and quartz sand of 2:1.Performance of chlorine dioxide inactivating Cryptosporidium oocysts in water was studied. The results showed that chlorine dioxide can kill Cryptosporidium oocysts effectively. Inactivate rate affected mostly by chlorine dioxide dosage, reaction time and temperature. And it decreased at high turbidity and high potassium permanganate index. The Cryptosporidium oocysts inactivated by chlorine dioxide is still remained integrality in shape.The neurotoxicology performance of chlorite was proposed. It is found that prolonged exposure to excessive chlorite for three generations can cause damage in cerebellum for rat pups in the second and the third generation, which leading to adverse impact on physical ability. And the learning memory ability seemed also impaired. The no observed adverse effect level of neurotoxicology for three generation Wistar rat is 30 mg/L.The results obtained in the paper not only provide theoretical basis for controlling microcystins and Cryptosporidium oocysts in potable water, but also bring out a feasible way of chlorine dioxide proxidation for water treatment, which is of important theory and application value. Furthermore, the toxicity of chlorite has also been complemented and can be references for extending the application of chlorine dioxide and standard developing.更多还原