【作者】 杨玉飞；

【导师】 陈玉成； 王琪；

【作者基本信息】 西南农业大学 ， 环境工程， 2005， 硕士

【摘要】 填埋是目前生活垃圾主要处置方式之一,现行的填埋处置技术仅把填埋场作为一个被动接受垃圾的系统,填埋场内的垃圾与外界的水气隔绝,填埋场内湿度低,无法为微生物生长提供一个适宜的条件,垃圾的生物降解受到了限制,填埋场稳定化时间长,渗滤液在长时间内仍会污染地表水和地下水。因此,设法改进填埋处理工艺,加速填埋场稳定化进程,从源头控制渗滤液的污染,对填埋场的再利用和渗滤液的处理有重要意义。 填埋场具有处理功能,通过改善填埋层内的空气和水分状况,利用微生物加速填埋层中有机物的降解,实现填埋场的稳定化,同时,垃圾填埋层对产生的渗滤液也会产生一系列的物理、化学和生物作用,降低渗滤液中污染物浓度,改善渗滤液的水质。本试验通过改变填埋场构造,将填埋场设计成准好氧填埋构造,外界空气在填埋层内部与外界环境的温差作用下自然通入填埋场并通过导气管在填埋层内扩散,改善填埋层内空气状况,实现利用和强化填埋场的处理功能来加速填埋场的稳定化和改善渗滤液水质。 依据准好氧填埋和厌氧填埋的设计原理,构建四个大型模拟填埋试验装置（21m×3.8m×6.0m）,两个为准好氧填埋结构,两个厌氧填埋结构作为参照。定期对各填埋装置渗滤液水质指标(COD_cr（以下简称COD）、BOD₅、NH₃-N、NO₃^--N和pH)进行监测,研究了准好氧填埋场渗滤液水质变化特性和填埋结构对渗滤液水质变化的影响。结果表明,准好氧填埋装置渗滤液COD最大值为26000 mg/L,各污染物浓度下降迅速,28周后COD、BOD₅和NH₃-N浓度分别稳定在300mg/L、50mg/L和30mg/L左右,下降率分别为98.9%、99.7%和99.0%,可生化性下降迅速,第13周后BOD₅/COD值基本稳定在0.1左右。厌氧填埋装置渗滤液COD最大值为53600mg/L,各污染物浓度下降缓慢,在48周COD、BOD₅和NH₃-N浓度仍高达1000mg/g、150mg/L和1200mg/L,实验期间BOD₅/COD值都高于0.1。准好氧填埋装置渗滤液在6周后呈弱碱性而厌氧在很长时间段内都呈弱酸性。准好氧填埋装置渗滤液NO₃^--N前期浓度较低,但在后期迅速上升,高达300mg/L,厌氧装置却基本检不出。准好氧填埋装置渗滤液COD、BOD₅和NH₃-N随时间的延续呈稳步下降趋势,没出现较大波动。厌氧填埋装置渗滤液COD在前期会累积上升并有较大波动,NH₃-N在试验后期仍有较大波动。对准好氧和厌氧填埋装置渗滤液各污染物浓度变化值进行指数拟合获得各污染物浓度衰减方程,其中准好氧填埋装置渗滤液污染物浓度衰减指数K_COD、K_BOD5和K_NH3-N分别为0.1484、0.1588和0.1374,厌氧填埋装置渗滤液污染物浓度衰减指数K_COD和K_BOD5分别为0.0459和0.0847。并根据拟合方程预测,准好氧填埋装置渗滤液COD、NH₃-N和BOD₅达到国家二级排放标准的时间分别为38、40和22周,厌氧填埋装置渗滤液COD和BOD₅达到国家二级排放标准的时间分别为61周和38周。 在试验期间进行了为期16周的渗滤液回流试验,研究了渗滤液回流填埋场对改善渗滤液水质的效果及其填埋结构对渗滤液回流效果的影响。结果表明,准好氧填埋装置渗滤液回流有利于渗滤液中COD、NH₃-N浓度的下降,其下降率分别为95.8%和89.8%,下降率高于厌氧填埋,且下降较为平稳。厌氧填埋装置渗滤液回流虽有利于渗滤液中COD浓度的下降,下降率为82.2%,但在回流初期浓度有升高的现象,NH₃-N却持续累积。试验中对渗滤液回更多还原

【Abstract】 Sanitary landfllling remains one of the most principal methods of municipal solid waste disposal at the present time. But, nowadays landilling technique just takes landfill as a passive storage waste place, the wastes in landfill were isolated with outside water and air. Moisture content in landfill was so low that it couldn’t provide microorganism with feasible condition, organic compounds in wastes biodegradation was restricted. Accompanied by differential settlement, landfill gas and leachate emissions, the dumped refuse will biodegrade slowly and gradually in the long process of landfill stabilization These emissions could last for decades or even centuries and result in a significant negative impact on the environment. So, every country has taking measures to ameliorate landfllling technique to accelerate landfill stabilization process and weaken leachate pollution.Disposal function is an important function of MSW landfllling. With the increasing of air and moisture content in landfill, compound organic material can be decomposed by microorganism quickly, so the stabilization process of landfill site is accelerated. At the same time, the compound organic material in leachate will be degraded by microorganism when leachate is in the recirculation, and the leachate quality is improved. Both change the landfill structure and bio-reactor landfllling are used disposal function of MSW landfill to improve leachate quality and landfill stabilization.Four large scale landfllling installations were built according to semi-aerobic landfllling and anaerobic landfllling theories. Two anaerobic landfllling installations used as contrast. The concentrations of COD, BOD5, NH₃^-N and NO₃^--N and pH were detected regularly. The results showed that, the concentrations of pollutants in leachate of semi-aerobic landfllling structure reduced more quickly than that in anaerobic landfilling structure, the concentrations of COD BOD₅ and NH3-N in leachate of semi-aerobic landfill treatment declined rapidly, and after 28 weeks keep about 300mg/L 50mg/ and 30mg/L and. The reduce rate reach 98.9%, 99.7% and 99.0% respectively and the value of BOD5/ COD also keep about 0.1 after 13 weeks. However the concentrations of COD BOD5 and NH3-N in leachate of anaerobic landfill treatment still keep about 1000mg/L 150mg/L. 1200mg/L and the value of BOD5/COD above 0.1 in whole stage. The concentration of NO₃^--N in leachate of semi-aerobic landfill structure in low state in prophase and it ascend quickly up to 300mg/L in anaphase But in anaerobic structure it can’t be detect. The pollutant concentrations in leachate of semi-aerobic landfilling structure reduced regularly, but which in aerobic landfilling leachate varied greatly in early period of experiment. Based on the experiment data, the attenuation equations of pollutants in leachate of semi-aerobic landfill structure were acquired.In order to study on influence of landfill structure on leachate recirculation effect, Leachate was recirculated into one semi-aerobic landfill and one anaerobic landfill and the concentrations of COD and NH3-N were detected regularly last sixteen weeks. The results showed that, leachate更多还原