【作者】 李光倜；

【导师】 李启彬；

【作者基本信息】 西南交通大学 ， 环境工程， 2013， 硕士

【摘要】 垃圾卫生填埋因具有技术可靠、工艺简单、管理方便、适用范围广和处理最彻底等一系列优点而得到较为广泛的应用。但垃圾卫生填埋仍存在诸多不足,尤其是其渗滤液处理难、费用高,若不加处理则会对周围环境水体产生二次污染,危害极大。目前,国内外学者对垃圾填埋场水质变化及水分运移规律已做了大量的研究,但有关渗滤液溶质在垃圾填埋场内的运移规律的研究却较少,因此,笔者进行了垃圾渗滤液溶质运移室内模拟试验,通过试验分析垃圾体填埋密度、渗滤液回灌量等因素对渗滤液溶质运移的影响,以深化对垃圾填埋场污染物去除机理的认识和理解,并借鉴溶液中溶质对流.弥散方程,建立渗滤液溶质运移的水动力弥散模型并对其求解、验证。研究结果表明：(1)首回合回灌结束后,渗滤液中Li+浓度随时间的变化趋势与渗滤液流出速率大体一致,即均呈现出先急剧增大,达到最大值后又缓慢减小的趋势,各自的最大浓度、平均浓度和淋出量均随填埋密度的增大依次减小,而垃圾柱对Li+截留量则随填埋密度的增大而增大。对比不同回灌量首回合回灌数据可知,随着回灌量的增大,Li+平均浓度相应增大,Li+截留量则相应减小。(2)本研究从第二回合开始用不含Li+的清水对垃圾柱进行淋洗,在用清水淋洗的过程中,各回合Li+的平均浓度呈现出随填埋密度的增大而减小的规律；从实验结果可以看出示踪物质的淋出是一个较为缓慢的过程,且垃圾装填密度越大,示踪物质越难以淋出,对于实施回灌的生物反应器填埋场,增大垃圾填埋密度可以在一定程度上增加水分和污染物质在垃圾体内的停留时间,有利于污染物的降解和稳定,也有助于加快生物反应器填埋场稳定化进程。(3)用描述淋洗过程常用的动力学模型对本实验数据进行模拟,由模拟结果可知,双常数模型模拟效果明显不及二级动力学方程模拟和Elovich模型模拟,而二级动力学方程模拟则略优于Elovich模型模拟。(4)用本研究建立的溶质运移模型对4#垃圾箱实验数据进行模拟,由拟合结果可知,本研究建立的溶质运移方程具有一定可靠性,用其预测含有溶质的渗滤液回灌后溶质运移规律有一定的参考价值。更多还原

【Abstract】 Since the waste sanitary landfill had advantages of reliable in technology, simple process, convenient management, widely applicability and most thorough treatment, it has widely used. But waste sanitary landfill still has many deficiencies, especially the leachate treatment is difficult and cost is high, if it was untreated, it will produce secondary pollution on the surrounding environment water, this will cause great disadvantage. At present, domestic and foreign scholars have done a lot of research on landfill water quality changes and moisture migration discipline, but the leachate solute migration discipline in the landfill had less research, therefore, the author did experiment indoor which can simulate leachte solute migration, through analysis the factors which can affect leachte solute migration-waste density and recirculation amounts, to strengthen the understanding of the landfill pollutant removal mechanism, and referenced the solute adverction-dispersition equations in solution, established leachte solute migration hydrodynamic dispersion model, at last, the author sloved the model and verified it.The results show that:(1) After the first recirculation cycle, the changing trends with time of leachate Li+concentration and leachate flow rate had the similar law, that both showed a sharp increase, reaching the maximum value and then slowly decreased, the greater density of waste, the maximum concentration、average concentration and Li+leaching amount are smaller, but the intercept amount of Li+in the waste had the opposite trend. Contrast the first recirculation cycle value of different recirculation amounts, with the increase of recirculation amounts, Li+concentration increases, the intercept amount of Li+reduces.(2) In this study, use water without Li+to leach waste from second cycle, during this proess, when the waste density increases, Li+concentration decreases; The experiment results shows that the tracer substances leaching is a relatively slow process, the greater density of waste, the tracer residue in the waste is more difficult to leach, for the bioreactor landfill which adopted leachate recirculation, to a certain extent, to increase the density of landfill can increase the time of water and pollutants exist in waste, it is conducive to degradation and stability of pollutants, it also can help to accelerate the process of bioreactor landfill stabilization.(3) Use the common kinetic models which describing the leaching process to simulate the experimental data, by the simulation result, the simulation results of the second-order kinetics equation and Elovich model are better than the first-order kinetics equation,the second-order kinetics equation is better than Elovich model.(4) Use the solute migration models which established in this study to simulate the experimental data of4#dustbin, by the simulation result, the model has a certain reliability, it also has a certain reference value when use it to forecast solute migration discipline after leachate recirculation.更多还原