【作者】 毛媛媛；

【导师】 王里奥；

【作者基本信息】 重庆大学 ， 环境工程， 2008， 硕士

【摘要】 垃圾渗滤液是垃圾在堆放和填埋过程中,由于发酵和雨水的淋溶、冲刷,以及地表水和地下水的浸泡而过滤出来的污水,对周边环境及填埋场场底土层污染严重,且污染持续时间长,易引起二次污染。垃圾渗滤液是一种成份复杂的高浓度有机废水,不同的填埋场或同一填理场的不同时间段,渗滤液的水量水质都有不同的特点,因而处理难度较大。有效微生物（EM）技术作为废水处理领域新兴的技术,由于其独特的优越性和传统方法不可比拟的优点,在渗滤液处理中具有非常广阔的应用前景。论文以重庆市长生桥垃圾填埋场渗滤液为试验水样,采用Fenton法和磷酸铵镁沉淀（MAP）法对垃圾渗滤液进行联合预处理。在此基础上,通过利用有效微生物EM菌的生物多样性和综合效应开展处理垃圾渗滤液的探索性试验,即以EM菌剂为生物增强剂,利用生物强化技术与传统生物治理技术相结合的方式探索垃圾渗滤液深度处理的技术条件和处理方法,以此提高垃圾渗滤液的处理效率。Fenton法和MAP法联合预处理垃圾渗滤液的结果表明:Fenton试剂对有机物的降解破坏是非常有效的,但对NH3-N的去除效果并不令人满意;而化学沉淀法对废水中有机物的去除率并不高。采用Fenton法和MAP法联合预处理垃圾渗滤液能够弥补各自不足,具有较好的效果。Fenton法处理垃圾渗滤液的最佳操作条件为:初始pH=5,FeSO4·7H2O投加量0.05mol·L-1,反应时间3h,nH2O2: nFe2+=1: 1。MAP法在以MgO+Na2HPO4·12H2O为药剂,pH值8.5,反应时间1h时,Mg: N: P=1: 1: 0.7较适宜。在此操作条件下,经联合预处理后的原水COD由6455mg/L降到1300mg/L,去除率79.86%;NH3-N由1119 mg/L降到251mg/L,去除率77.57%;TP由20.55 mg/L降到2.1mg/L,去除率89.78%;BOD5/COD从0.2提高到0.5,明显改善了渗滤液的可生化性,有利于后续生物处理。Fenton法操作方便, MAP法形成的磷酸铵镁沉淀可以作缓释肥（SRFs）或用作结构制品的阻火剂,不会造成二次污染,可实现废物资源化。EM技术处理垃圾渗滤液的影响因素研究表明:EM中的有效微生物能够起到生物增强剂的作用,明显促进污染物的降解,对垃圾渗滤液中的COD、NH₃-N、TP均有明显的去除效果。通过正交试验和单因素分析确定EM技术处理垃圾渗滤液的各因素适宜范围为:反应时间48 h～96 h,曝气时间为12h～36h,低流量间歇曝气,接种量（VEM: V水）为1/5000～1/1000,进水pH值7～8.5。EM处理垃圾渗滤液各因素的最佳水平组合为:反应时间48h,VEM: V水=1/2000,曝气时间12h,进水pH 8.5。EM技术与生物膜法相结合处理垃圾渗滤液的研究表明:以陶粒为填料的EM生物膜系统,能够为EM菌的生长繁殖提供良好的环境,EM生物膜系统启动时间为8～9d,大大缩短了系统的启动时间;COD、NH3-N和TP去除率分别达到80%以上。EM生物膜系统正式运行期,COD去除率在48h达到最大值84.65%,满足GB16889-1997生活垃圾填埋污染控制二级标准;NH3-N去除率在72h达到最大值81.09%,达到GB8978-1996污水综合排放二级标准;TP去除率48h后达78.85%时,出水浓度可以达到GB8978-1996污水综合排放一级标准。同单纯使用EM菌处理垃圾渗滤液相比,去除率均有较大幅度提高。EM技术处理垃圾渗滤液克服了以往渗滤液处理工艺中气味恶臭难闻的弊端;污泥产量小,避免了污泥处理带来的经济消耗和二次污染问题;处理后出水色度明显降低;避免了填料堵塞的问题;运行成本低,操作简便。更多还原

【Abstract】 Landfill leachate is produced by fermentation, rainwater leaching and scouring, surface water and groundwater immersion when waste is piling up. This kind of wastewater may cause serious pollution, which can last for a long time and cause secondary pollution easily, to surrounding area and soil layer of landfill. Landfill leachate, which composition is quite complicated, is a kind of high concentration of organic wastewater and has different characteristics in water quality and quantity in different locations and hours. Therefore, treatment of leachate is difficult. Effective microorganisms （EM） technology which is an emerging technology in wastewater treatment has broad applications in leachate treatment as a result of its unique advantages which are much better than traditional methods.In this dissertation, landfill leachate of Chongqing Changsheng Bridge Municipality Sanitary Landfill was chosen to be treated with Fenton process and Magnesium Ammonium Phosphate Precipitation （MAP）. Then exploratory experiments were carried out by using the biological diversity and combined effect of EM to treat leachate. Through the combination of bio-augmentation technology and traditional biological treatment technology with EM as biological enhancer, technical conditions and methods of landfill leachate advanced treatment were explored to improve landfill leachate treatment efficiency.Fenton process and MAP were combined to study the effect of landfill leachate pretreatment. It was showed that Fenton process was very effective for the degradation of organic matter, but ammonia removal was unsatisfactory, and chemical precipitation was not effective for organic removal. The method of leachate pretreatment by combination of Fenton process and MAP was able to make up their deficiencies and get good results. The optimum operation conditions of Fenton process were as follows: leachate pH （5）, Fe2+ addition （0.05mol·L-1）, reaction time （3h）, nH2O2: nFe2+=1: 1. The molar ratio of Mg: N: P=1: 1: 0.7 was better for treatment effect when other factors of MAP were as follows: agents （MgO+Na2HPO4·12H2O）, pH （8.5）, reaction time （1h）. Under the optimum operating conditions, COD of the leachate pretreated decreased from 6455mg/L to1300mg/L with removal efficiency of 79.86%, NH3-N decreased from 1119 mg/L to 251mg/L with removal efficiency of 77.57%, and TP decreased from 20.55 mg/L to 2.1mg/L with removal efficiency of 89.78%. At the same time, BOD₅/COD ratio was improved from 0.2 to 0.5 as well. Through this method, biodegradability of leachate was significantly improved and it was helpful for the follow-up biological treatment. Fenton process was easy to operate and magnesium ammonium phosphate produced in MAP can be used as slow-release fertilizers or fire-retardants of structural products. Instead of causing secondary pollution, this way could realize waste resource recovery.The study on the influencing factors of EM technology in landfill leachate treatment indicated that effective microorganisms in EM as biological enhancer played a strong role and promoted pollutant degradation obviously. The removal efficiencies of COD, NH₃-N and TP were significant. Orthogonal experiment and single factor analysis were carried out to determine the optimum operating conditions. The results were as follows: reaction time（48h～96h）, aeration time（12h～36h）, low-flow intermittent aeration, EM addition （VEM: Vwater, 1/5000～1/1000） and leachate pH（7～8.5）. The optimum operating conditions of EM technology were as follows: reaction time （48h）, EM addition （VEM: Vwater, 1/2000）, aeration time （12h） and leachate pH （8.5）.The study on the combination of EM technology and biofilm process to treat landfill leachate indicated that under the optimum operating conditions, the biofilm system with ceramic granules as filler was able to provide good environment for EM to grow and reproduce, and the system start up time which was greatly shortened was only 8～9d. The removal efficiency of COD, NH3-N and TP was respectively over 80%. During the formal operational stage of EM biofilm system, COD removal efficiency reached the maximum of 84.65% after 48h which was up to "Tier 2" Emission Standards of MSW Landfill Pollution Control （GB16889-1997）, NH3-N removal efficiency reached the maximum of 81.09% after 72h which was up to "Tier 2" Integrated Wastewater Discharge Standard （GB8978-1996）, and TP removal efficiency reached the maximum of 78.85% after 48h which was up to "Tier 1" Integrated Wastewater Discharge Standard （GB8978-1996）. Compared with the method of using EM to treat leachate alone, this way significantly improved the removal efficiencies of COD, NH₃-N and TP. This technology conquered the disadvantage of traditional landfill leachate treatments which had horrible smell in the treating process, and also had some other advantages such as less amount of sludge which could avoid the problems of economic consumption and secondary pollution in sludge treatment, better removal effect of water color, elimination of the blockage of the filler, low operating costs, and easy operation.更多还原