【作者】 赵莉；

【导师】 张志杰；

【作者基本信息】 西安建筑科技大学 ， 环境工程， 2003， 硕士

【摘要】 垃圾渗滤液是城市垃圾卫生填埋过程中产生的二次环境污染问题之一，其处理则是保证垃圾卫生填埋的重要措施，也是解决垃圾污染问题的重要组成部分。垃圾渗滤液是一种污染负荷很高的有机废水，其主要成分是垃圾中有机物降解过程中产生的中间体有机酸和溶解性营养盐。典型的渗滤液中BOD₅含量可高达（1-5）×10⁴mg／L左右。因此垃圾渗滤液的处理一直是世界性的一个难题。目前国内外垃圾渗滤液的工艺研究很多，而且存在着工艺复杂，停留时间长，处理成本高，处理后的水质仍有个别项目难以达标等问题。同时，单一研究较多，综合分析较少。因此，对现有研究方法进行综合分析、对比，从中筛选优化几种适合我国西北地区垃圾渗滤液的处理方案，是加快这一领域研究和应用的一条捷径，具有重要的实用价值。 本文首先对垃圾填埋场渗滤液的产生机理、产量及其影响因素、水质特征及其变化规律和填埋垃圾中污染物的溶出规律进行了分析探讨。其次，对渗滤液的处理特性作了深入的分析。处理特性指那些影响其处理工艺选择及处理效果的主要指标的特性及其变化规律，如：水质的季节性变化（可通过调节池进行调节）；水质随填埋龄的变化问题（COD、BOD₅、NH₃-N、金属离子等随垃圾的初期调节、转化、产酸、产甲烷及成熟阶段的进程而变化）；污染成分及其变化的复杂性（体现在渗滤液中所含污染物多、难降解物多、有毒有害物多、地区差异大，短期和长期变化大）。通过对现有研究成果（处理方案、处理方法及处理工艺）的分析比较，结合西北地区垃圾填埋场多建于山谷地带，渗滤液污染物浓度高、氨氮含量高的特点，提出两种符合西北地区特点的处理方案：1．渗滤液与城市污水联合处理 2．建设独立的场内处理系统。其中方案一是首选方案，此方案比较经济，易于实现，操作管理方便。推荐采用如下工艺流程（1）渗滤液→调节池→吹脱塔→混凝沉淀→厌氧生物处理→沉淀池→污水厂；（2）渗滤液→循环回灌→吹脱塔→氧化塘→污水厂。采用方案二时的工艺流程如下：（1）渗滤液→调节池→吹脱塔→一级厌氧池→二级厌氧池→沉淀池→曝气池→二沉池→混凝沉淀→水生植物塘；（2）渗滤液→调节池预曝气→混凝沉淀→调蓄池→曝气池→沉淀池→后曝气→好氧氧化塘→砂滤→湿地处理；（3）渗滤液→调节 西安建筑科技大学硕士学位论文 池一吹脱塔一气浮池一热交换器一厌氧反应器一A／0接触氧化池一沉淀池一微滤 器一纳滤器一出水。无论选用哪种方案，渗滤液均须进行必要的物化预处理，其中 氨氮的去除是一难点，本文对渗滤液氨氮的脱除技术一吹脱法、电化学氧化法、混 凝沉淀法、生物脱氮技术进行了综合研究，对确保渗滤液的后续主体工艺一生物处 理稳定运行并保证较低的出水NH。”－N，TN浓度具有重要意义。‘上述研究结果对西北地区城市垃圾填埋场渗滤液的处理方案选定有一定的指 导篙义和实用价值。更多还原

【Abstract】 Landfill leachate is one of the environment pollution which caused by the municipal waste landfill. The treatment of leachate is an important aspect of solving the domestic refuse landfill pollution. Landfill leachate is a complex wastewater which the composition of contaminants are medium organic acids and soluble nutrients matter from waste decomposition. In general, the concentration of contaminants is very high, such as BODs equal to (1-5) X104 mg/L. Therefore, landfill leachate treatment is a difficult problem for the researchers and engineers in the world. At present many researchers have been studying on the leachate treatment technologies, but there still are many difficult points: complex treatment process, longer sludge retention, higher costs and poor treatment results, more simplex and lesser analysis of the treatment technologies. Therefore, it is a shortcut for the study and usage of landfill leachtate treatment strategies in the northwest areas to select and optimize treatment technics by analyzing and contracting their advantages and disadvantages.Firstly, the generation principals, the quantity, the influential factors, quality characters and its changing law, the leaching rule of contaminants are studied. Secondly, it analyzes treatment characteristics of the leachate treatment which refer to the main items’ changing law, for example: the quality changing largely with the season (solved by building a balancing pond); the quality changing with the age of the landfill (in the different refuse decomposition stage the concentration of COD, BOD5, NH3-N, heavy metals are quite different ); the complexity of the contaminants (represented by the complex poisonous pollution matter which vary in different areas ). And then, in terms of the northwest areas landfill leachate’s characteristic, some of the projects and methods are selected. It is true that most of the municipal landfill lies in the natural village and the economic of the northwest areas is still backward. The two projects are: 1. combining the leachate with the municipal wastewater. 2. building the on-site wastewater treatmentplant. The first one is rather economic and easy to carry out. It is also easy to manage and maintain, so the first one is superior to the second. The recommended leachate treatment process are as follows: (1) leachate → facultative pond → air-stripping → chemical precipitation→anaerobic filter→settling tank→WWTP. (2) leachate →recirculation → air-stripping→aerated pond→WWTP. If the second project is selected, the process are: (Dleachate→facultative pond→air-stripping→anaerobic reactor 1 →anaerobic reactor 2 → settling tank→aerated pond→chemical precipitation→plants pond.(2) leachate→ pre-aeration → flocculation → neut. tank → aeration tanks → settling → post oxidation → aerated lagoons → filtration → wetland. (3) leachate→balancing tank → air-stripping → flocculation→heat exchange→anaerobic reactor→A/O aerobic lagoons→precipitation→ nanfiltration→river. Physical-chemical pretreatment is very important for the leachate treatment, especially removal of ammonia. At last, the denitrification technologies: air-stripping, electric-chemical oxidation, chemical precipitation and bio-denitrification are reviewed. It is essential for the following bio-treatment process and ensuring the discharged water with low concentration of NH3-N.The results studied above have guide and practical sense for the landfill leachate treatment selection in northwest areas of china.更多还原