为了研究城市生活垃圾焚烧(municipal solid waste incineration,MSWI)底灰在填埋场中的浸出特性,在实验室条件下对MSWI底灰进行了为期48周的模拟淋溶实验,并对产生的渗滤液的性质进行了分析。模拟实验包括缺氧柱和好氧柱,分别测定了2个柱中产生的渗滤液的p H、ORP、TP、TN、COD和TOC等指标。实验结果发现,渗滤液的性质的随时间和模拟降雨次数的增加而不断发生变化,其中p H值持续下降,而ORP则逐渐升高然后下降;COD、TOC、TP、和TN浓度在前8周内依次达到最大值而后降低,变化趋势可分为急速上升阶段、快速下降、缓慢下降和基本稳定4个阶段。从整个实验过程来看,p H的下降较缓慢,在实验进行到第48周时,缺氧柱和好氧柱的p H值分别为12.33和11.43,仍维持在强碱性。在实验结束时,2组实验中产生的渗滤液的p H、TOC和COD等3项水质指标均超出《城镇污水处理厂污染物排放标准》(GB18989-2002)一级A排放标准。
A simulated landfill experiment using municipal solid waste incineration( MSWI) bottom ash was conducted for 48 weeks in the laboratory under anoxic and aerobic conditions. The characteristics of MSWI bottom ash leachate generated from the simulated experiment were analyzed,such as p H,oxidation-reduction potential( ORP),total phosphorous( TP),total nitrogen( TN),chemical oxygen demand( COD),and total organic carbon( TOC). The p H values continuously decreased,while the ORP gradually increased and then decreased with time. The values of COD,TOC,TN,and TP reached maximum levels in turn within eight weeks and then decreased with time,and the variation tendency of the TP,TN,COD,and TOC values could be divided into four phases: zooming,rapidly decreasing,slowly decreasing,and stabilizing. According to the experimental results,the p H values were 12. 33 and 11. 43 under anoxic and aerobic conditions at the 48 th week,respectively. At the end of the simulated experiment,the values of TN,TOC,and COD surpassed the limits according to Class 1A of the "Discharge Standard of Pollutants for Municipal Wastewater Treatment plant"( GB18989-2002).