【作者】 薛丹丹；

【导师】 刘丹；

【作者基本信息】 西南交通大学 ， 环境工程， 2008， 硕士

【摘要】 垃圾渗滤液是一种成分复杂的高浓度有机废水,处理难度较大,将其与城市污水合并处理为目前一种经济的处理方案。在渗滤液通过管道送往城市污水处理厂时由于物理、化学、生物等原因,易出现输送管道结垢堵塞问题。为探究渗滤液输送管道结垢堵塞机理,本文先进行了结垢理论分析,然后对长安垃圾填埋场（四川最大的垃圾填埋场）渗滤液水质和输送管道中垢物组成做了分析,再通过室内静、动态实验研究影响结垢的主要因素,其中静态实验通过测定渗滤液失钙率（失钙率越大,表明沉淀生成越快,结垢程度越大）的大小、动态实验通过模拟渗滤液的输送并测定管道中的结垢量来判断各影响因素对结垢堵塞的影响,最后提出结垢的评价方法和防垢除垢对策。对长安垃圾填埋场输送管道中垢物测定结果表明垢物主要组成为碳酸钙,含量约84.2%。渗滤液水质分析发现渗滤液钙硬度高达455.45mg/L,碱度（HCO3-）高达173.82mol/L,过高的钙硬度和碱度为垢物的形成提供了条件。静态实验结果表明,在其他因素恒定时:失钙率随钙硬度的增大而增大,钙硬度分别为308.78mg/L、494.04mg/L、694.75mg/L和880.01mg/L时,失钙率分别为39.63%、49.69%、58.72%和69.81%;失钙率随碱度的增大而增大,碱度（HCO₃^-）分别为89.7mol/L、104.91mol/L、114.86mol/L、133.38mol/L和170.04mol/L时,对应失钙率分别为19.84%、24.96%、26.67%、31.78%和43.72%;失钙率随pH的升高而增大,当pH分别为6、7、7.5、8和9,对应失钙率分别为16.43%、19.84%、21.55%、40.31%和48.84%;温度在15℃和35℃之间时,随着温度的升高,失钙率逐渐增大,且增大较缓慢;结垢程度随时间的推移逐渐减小。动态实验结果表明:同一管材的管道结垢量随流量的增大而增多;流量相同时,PVC管比PE管结垢量稍大。结垢的评价方法有饱和指数法、稳定指数法、结垢指数法和临界pH值法等,其中稳定指数法最常用,临界pH值法最合理。可通过调节水质、改变外界条件和加防垢剂等方法来防止结垢的发生。除垢对策中化学除垢技术应用较广。本文可为填埋场的正常运行和渗滤液的正常管道输送提供科学依据。更多还原

【Abstract】 Leachate is a type of organic wastewater containing large amounts of pollutant with high concentration, and difficult to treat. Now an economical way is to treat it in combination with municipal sewage. On the way of transporting leachate in pipeline to municipal sewage treatment plant, the pipe would be scaled and clogged due to some physical, chemical and biological reasons.To research the scaling mechanism of the leacahte pipe, The paper analyzed the scaling in theory first, then mensurated the leachate’s water quality and the makeup of the pipe scaling from Chang’an waste landfill, which is the biggest one in SiChuan , and then studied the main facators influencing the scaling by static and dynamic experiments. The static experiment judged the influence by calcium’s losing rate(The faster of the calcium’s losing rate, the quicker of the depositing , and the more serious of the scaling degree.), by simulating the transportation of the leachate, the dynamic experiment estimated the influence with the scaling quantity of the pipe. At last, the evaluating methods, prevention and cure against the scaling were brought forward.The study of the scaling from Chang’an Waste Landfill ’s leachte pipe showes that the main makeup is calcium carbonate, whose content is about 84.2%.The analyzing of the water quality indicates that the calcium strength is 455.45 mg/L, and the alkalinity is 173.82 mol/L, which supplies the scaling with qualification.The experiment is aiming at the main influence factors on sacling of leachate pipe such as calcium strength, alkalinity, pH, temperature, flux, time , pipe material and so on.The static state experiment shows that when other factors are invariable. The calcium’s losing rate will increase with the calcium strength’s augment. When the calcium strength are 308.78 mg/L, 494.04 mg/L, 694.75mg/L and 880.01 mg/L, the calcium’s losing rate are 39.63%, 49.69%, 58.72% and 69.81%; Also, the calcium’s losing rate will rise with the alkalinity or pH’s increasing. When the alkalinity are 89.7 mol/L, 104.91 mol/L, 114.86 mol/L, 33.38 mol/L and 170.04 mol/L, the calcium’s losing rate are 19.84%, 24.96 %, 26.67%, 31.78% and 43.72%; When pH are 6, 7, 7.5, 8 and 9, the calcium’s losing rate are 16.43%, 19.84%, 21.55%, 40.31% and 48.84%. While the temperature changes from 15℃to 35℃, the calcium’s losing rate will increase with the augment of calcium strength slowly. The calcium’s losing rate will decrease as the time going on. The dynamic experiment indicates that when the pipe’s material is uniform, the scaling state will augment with the flux’s increasing. when the flux is steady, the PVC pipe’s scaling degree will deeper than the PE pipe’s.The ways to estimate calcium carbonate’s scaling are Langelier’s, Ryznar’s, Puckorius’s and Feitler’s methods. The Ryznar’s method is in common use. and the most reasonable is Feitler’s method. By controlling the water quality , changing the outside condition ,or adding medicament which can preventing the scaling’s formation,we can avoid the scaling. The chemical disposing measurement which is widely used can get rid of the scaling.The paper can give scientific reference to the waste ladfill’s naturally running and leachate’s favourable pipeline transportation.更多还原