【作者】 丁湛；

【导师】 关卫省； 刘建；

【作者基本信息】 长安大学 ， 地质工程， 2009， 博士

【摘要】 随着社会的发展及生活水平的提高，垃圾的产生量越来越大，垃圾渗滤液已成为难处理有机废水的重要来源，对水源安全构成了较大的威胁。因而，垃圾渗滤液处理技术已成为环境工程领域的重要研究课题。目前对垃圾渗滤液的相关研究主要集中在采用生物法、物化法等技术的处理方面，对成分复杂且难降解有机物含量高的渗滤液处理效果较差。总体而言，我国有关垃圾渗滤液的研究仍处于初级阶段，对渗滤液的组分特征、物相特性、处理机理等缺乏足够的认识，而且尚没有能有效地应用于实践的垃圾渗滤液处理方法，在很多方面仍需深入研究。本文以西安市江村沟垃圾填埋场所产生的垃圾渗滤液为研究对象，分析渗滤液中物质的存在状态及颗粒物的组成结构特征，并在此基础上进行混凝预处理及微波条件下类fenton高级氧化处理方法研究，最后通过微观分析探讨处理机理。垃圾渗滤液的常规指标及组成特性不仅可以反映其污染特性，而且在很大程度上影响渗滤液的处理效果。首先测定了垃圾渗滤液的常规水质因子及污染物含量，并采用GC及GC-MS技术对垃圾渗滤液有机相的微观结构进行了分析，由GC谱图解析推断渗滤液的溶液相中含有丁酸或辛酸、苯酚、吲哚及多环芳烃等有机物；由GC-MS解析可知其有机物主要为有机酸，约占53％，其次醇及酚类约占18％，烷烃约占7％。通过ξ电位及界面张力的测定，分析了垃圾渗滤液的胶体结构特征，为混凝预处理及高级氧化处理提供了依据。垃圾渗滤液中的大量污染物以颗粒物状态存在，对渗滤液中颗粒物的粒径分布及含量进行了分析，并进行酸化前后的DSC和FTIR红外谱图分析。结果表明，渗滤液中大于30μm的颗粒物大多以絮状存在，10μm左右的颗粒物多以粒状体存在，且颗粒物粒度不均较分散；渗滤液颗粒物的DSC测定谱图共出现五个特征峰，各峰值特征明显，总热焓较大，而酸化后仅出现三个特征峰，各峰值不明显且峰位置均向高温区移动，总热焓减小。由FTIR红外谱图可以推断原渗滤液颗粒物中有机物大体为以芳环为骨架及醛或酮缩聚的结构，含有不饱和的碳氧键，基团主要有酚羟基，羧基，甲基和氨基等。在对垃圾渗滤液中颗粒物及胶体微粒讨论的基础上，探讨了混凝对渗滤液中不同状态污染物的去除作用，分析了混凝剂AlCl₃及PAM的投加量、pH值条件、水力条件、沉降时间等因素对渗滤液中COD、NH₃-N及浊度去除的影响，并确定最佳混凝条件，此时浊度可降低98．22％、COD和NH₃-N的去除率分别可达到31．55％和22．79％。在对垃圾渗滤液中各类污染物系统分析的基础上，提出了微波条件辅助处理老龄垃圾渗滤液的类Fenton法高级氧化技术，并通过正交试验设计及灰色关联理论分析了试验影响因素，优化了反应条件，得到了垃圾渗滤液最佳处理条件为溶液初始pH=3、GAC加量10g/L、Fe离子量为333．2mg／L、微波处理功率为720w、微波处理时间为30min、30％的H₂O₂加量为10ml／L。根据微波及催化氧化的作用机理分析了COD及NH₃-N去除率随处理条件变化的不同特征及原因，并分析了微波及H₂O₂的催化氧化作用。对处理后水样的GC及GC-MS分析可知氧化处理后的渗滤液中各类有机物及多环芳烃都已被降解为CO₂和H₂O或结构相似的化合物，而且含量大大减少。在微波作用分析的基础上，分析了·OH对垃圾渗滤液中几种典型的有机污染物烷烃类、芳烃类、氮杂环类、芳环类等的降解途径及转化历程，并讨论了GAC在反应中的作用，进行了微波条件下类Fenton法处理垃圾渗滤液的反应动力学研究，提出适合微波催化高级氧化处理条件的催化氧化反应动力学模型-dC/dt=kC^2．08（C′）^0．72。更多还原

【Abstract】 With the development of society and living standards,the amount of wastes increases dayby day.Landfill leachate has become an important source of refractory organic wastewater,which threats the security of water source.So treating technique on landfill leachate has beenvery important in field of environmental engineering.At present,main researches on landfill leachate focuses on the treatment methods ofbiological and physico-chemical,but these methods is less effective to landfill leachatebecause of complex composition and high content of refractory organic matter.Overall,thestudy about landfill leachate is still in primary stage.The component and phase characteristicsand the treatment mechanism of the leachate are all lack of analysis.What’s more,there arenot effective methods to treat the landfill leachate in practice,so the study is still needed inmany aspects deeply.In this dissertation,leachate from the buried landfill in Jiangcun gou ofXi’an is studied on analysing the state of material and the structural characteristics ofparticulate in leachate.And then landfill leachate is treated by coagulation and advancedoxidation with microwave,and the mechanism is studied on the basis of micro-analysis.The conventional indicators and the composition characteristics of landfill leachate canreflect its pollution characteristics and impact the treatment effect of leachate in a large extent.At first,the conventional indicators and content of pollutants in landfill leachate aredetermined,and the micro-structure of organic phase of landfill leachate is analyzed by GCand GC-MS.Butyric acid,phenol,indol and polycyclic aromatic hydrocarbons are inferredin the solution phase of leachate by GC,and 53% of organic acids,18% of alcohol andphenols,and 7% of alkanes are detected in leachate by GC-MS.The colloidal structure oflandfill leachate is analyzed by determination ofξ-potential and the interfacial tension,whichprovide the basis to pretreatment by the coagulation and treatment by advanced oxidation.A large number of pollutants existence with particulate matter in landfill leachate,so thesize and content of particulates are analyzed.The characteristics of particulate is detected byDSC and FTIR before and after acidizing of leachate.The results showed that the particleslarger than 30μm are mostly flocculent and about 10μm particles are mostly granular and thesize of particles are not uniform.Five characteristic peaks appear in the spectra of DSC and the peaks are great,and the value of total enthalpy is greater.Three characteristic peaksappear in the spectra after acidification and the peaks are small,and the position of peak ismoved to the high temperature zone and the value of total enthalpy decreases.The original ismade from the skeleton of aromatic and condensation of aldehyde or ketone and unsaturatedcarbon-oxygen bond.Phenolic hydroxyl,carboxyl,methyl and amino can be inferred inorganic particles by FTIR.On the base of characteristics particulate and colloidal of leachate,the effect of thecoagulation is studied for the removal of pollutants in different phase.The effect of dosage ofAlCl₃ and PAM,pH,hydraulic conditions,and the settlement time is analyzed on the removalCOD,NH₃-N and turbidity of landfill leachate,and the optimum coagulation conditions aredetermined.At this time,the turbidity is reduced by 98.22%,and the removal rates of CODand NH₃-N is 31.55% and 22.79%.Advanced oxidation by microwave is use to treat landfill leachate on the basis of thesystematic analysis of various pollutants in leachate.With the help of orthogonal design andanalysis of gray relational theory,reasonable test conditions are determined:the initialconditions of pH=3,the volume of GAC is 10g/L,the weight of Fe（Ⅱ）is 333.2mg/L,thepower of microwave is 720w,the treating time of microwave is 30min,and the amount ofH₂O₂（30%）is 10ml/L.The different characteristics and the reasons of the removal rate ofCOD and NH₃-N with the changes of treating conditions was analyzed based on mechanismof microwave and catalytic oxidation.And the catalytic oxidation effect of microwave andH₂O₂ is analyzed.Various organic compounds and polycyclic aromatic of landfill leachatehave been degraded to CO₂ and H₂O or similar compounds after treatment and the content isreduced significantly.On the base of the microwave role,the degradation and transformation process of typicalorganic pollutants in landfill leachate,such as alkane,aromatic,aromatic amino compound,and heteroaromatic compound,are studied by the role of the·OH.The role of GAC in thereaction is discussed.Kinetics of advanced oxidation with microwave is researched to get thekinetics model:-dC/dt=kC^2.08（C′）^0.72.更多还原