【作者】 王琨；

【导师】 晋日亚；

【作者基本信息】 中北大学 ， 环境工程， 2020， 硕士

【摘要】 目前,卫生填埋是城市生活垃圾处理常用的方法,但该方法会产生对环境和人体危害极大的垃圾渗滤液。本文以某生活垃圾填埋场产生的垃圾渗滤液为研究对象,以COD的去除率为主要指标,通过对实际水质指标的检测分析和传统水处理工艺的对比研究,提出混凝/水力空化强化二氧化氯技术处理垃圾渗滤液的技术路线。本研究主要包括以下几个方面的内容:（1）混凝法处理原始垃圾渗滤液试验研究。结果表明,最佳混凝剂组合为PAC+PFS,投加顺序为PAC先于PFS投加,复配混凝剂比例为m（PAC）:m（PFS）=3:1,复配混凝剂投加总量为1451.80 mg/L,助凝剂PAM投加量为3 mg/L,反应pH=5,分别快速和慢速搅拌2 min和20 min,搅拌速度分别为200 r/min和50 r/min,静置时间为30 min。在此条件下,初始值为2903.76 mg/L的COD去除率为60.14%,混凝后COD剩余1157.58mg/L。（2）研究了采用水力空化（HC）在进口压力为0.4 MPa下处理原始垃圾渗滤液。通过实验研究了孔板的开孔率、布孔方式、空化时间等操作参数对渗滤液中COD、BOD₅/COD的影响,并对其进行能效评估。结果表明,在上述条件下,环状孔板处理效果优于辐射状孔板,且开孔率为0.0439孔板效果最佳,在最佳运行时间60min时COD去除率为22.63%,可明显提高水质的可生化性,BOD₅/COD上升54.55%。能量利用率分析同样得出开孔率0.0439的孔板能量利用率最高,为8.24×10^-3 mg COD/J。（3）单独ClO₂对混凝后垃圾渗滤液处理试验研究。该部分考察了ClO₂的用量和反应pH对处理效果的影响。结果显示,ClO₂使渗滤液COD大幅升高,ClO₂仅能够将有机物破坏而无法矿化。在ClO₂处理垃圾渗滤液过程中,在pH=4-8范围内COD变化率相同,pH=4时COD升高幅度最大,升高53.44%;ClO₂用量达到400 mg/L时COD升高率为71.72%,继续增加ClO₂用量后COD几乎无变化。（4）HC/ClO₂处理混凝后垃圾渗滤液试验研究。在单独空化的基础上,考察了ClO₂的用量和反应pH对处理效果的影响。结果发现,HC/ClO₂最佳操作条件为:pH=5,ClO₂投加初始浓度为25 mg/L,在进口压力0.4 MPa的条件下反应120 min即可达到最高COD去除率。经HC/ClO₂处理后,COD由1157.58 mg/L降至476.69 mg/L,去除率达到58.82%。（5）HC/ClO₂系统自由基验证实验。以邻苯二甲酸为·OH捕获剂,用荧光分光光度法对捕获产物进行分析,结果显示,HC和HC/ClO₂均能产生·OH,且HC/ClO₂体系所捕获·OH远高于单独HC过程。同时,以Rh B为污染物模型,三氯甲烷为O₂^·-清除剂,叔丁醇为ClO·清除剂进行的实验结果显示,两种自由基淬灭剂的加入使HC/ClO₂对Rh B的去除效率降低,表明HC/ClO₂体系能够产生O₂^·-和ClO·。更多还原

【Abstract】 The main way to deal with municipal solid waste was sanitary landfill,which produced landfill leachate.In this paper,the landfill leachate produced by a household garbage landfill site is taken as the research object,COD removal rate as the main index,through the analysis of water quality and the comparison of the existing treatment process,the method of treatment of landfill leachate by coagulation combined with advanced oxidation technology is proposed.This study mainly includes the following aspects:（1）Experimental study on treatment of initial landfill leachate by coagulation method.PAC and PFS was selected as the coagulant,the order of addition is PAC before PFS addition,the ratio of m（PAC）:m（PFS）3:1,the dosage of coagulant and PAM 1451.80 mg/L and 3mg/L respectively,reaction pH=5.The stirring speed was 200 r/min for 2 minutes（min）,and the stirring speed was 50 r/min for 20 min.After the reaction,the stirring was allowed to rest for 30 min.Under these conditions,the removal rate of the COD 60.14%,and the content of COD decreased from 2903.76 mg/L to 1157.58 mg/L.（2）The treatment of initial landfill leachate with Hydrodynamic Cavitation（HC）under inlet pressure of 0.4 MPa.In the experiments,the influence of operating parameters such as orifice opening rate（β）,the arrangement of orifice and reaction time on chemical oxygen demand（COD）and BOD₅（biochemical oxygen demand）/COD removal in leachate was studied,and the energy efficiency was evaluated.The results show that under the above conditions,the removal rate for COD of orifice plate with annular arrangement orifice was better than that of orifice plate with radiation arrangement orifice.And the orifice plate with an orifice opening rate（β）of 0.0439 had the best effectiveness.The COD removal rate was22.63%when the optimal operation time was 60 min.The biodegradability of water was obviously improved,and the BOD5/COD was increased by 57.27%.The energy efficiency evaluation also showed that the energy efficiency of the orifice plate withβ=0.0439 was the highest,which was 8.24×10^-3 mg COD/J.（3）Treatment of landfill leachate by ClO₂ alone after coagulation.The effects of ClO₂dosage and reaction pH on the treatment were investigated.The results showed that ClO₂greatly increased COD in leachate,this suggested that ClO₂ could only destroy organic matter but not mineralize it.In the process of ClO₂ treatment of landfill leachate,in the range of pH=4-8,the change range of COD was the same.When pH=4,the increase range of COD was the largest,53.44%.When ClO₂ dosage reached 400 mg/L,COD increased by 71.72%,and COD hardly changed after further increasing ClO₂ dosage.（4）Experiment of landfill leachate treated by HC/ClO₂ after coagulation.On the basis of HC,the effects of ClO₂ dosage and reaction pH on the treatment effect were investigated.The results show that the best operating conditions for HC/ClO₂ were:pH=5,the initial concentration of ClO₂ was 25 mg/L,and the maximum COD removal could be achieved after the reaction for 120 min at the inlet pressure of 0.4 MPa.After HC/ClO₂ treatment,the content of COD decreased from 1157.58 mg/L to 476.69 mg/L,and the removal rate reached58.82%.（5）Free radical verification experiment.The phthalic acid was used as the·OH capture agent,the capture products were analyzed by fluorescence spectrophotometry.The results showed that both HC and HC/ClO₂ could produce·OH,and the capture·OH of HC/ClO₂system was much higher than that of HC process alone.At the same time,Rh B was used as a pollutant model,the addition of trichloromethane which was O₂^·-scavenger and tert-butanol was ClO·scavenger were all reduced the removal efficiency of on Rh B traed by HC/ClO₂,indicating that HC/ClO₂ system could produce O₂^·-and ClO·.更多还原