新型AE/AN生活垃圾生物填埋工艺开发及机理数值模拟研究

The disposal method of landfilling MSW is still the main manner for now and a long period afterwards.It is laid more and more importance these years.However,the most extensively appllied anaerobic landfilling method still have shortcomings such as long stabilization period,heavy pollution and high cost on management.This research will intensively combined the advantages of aerobic and anaerobic landfilling method,and explored one new type of landfill in which the shorter stabilization period,lower pollution on environment and bio-gas recycling purposes will be realized in much extent. In the initial period of fresh MSW infilled, aerobic condition will be creatived by pumping into air artificially.Then the moisture and nutrient can be offered more fluently to bacteria, and aerobic bacteria,also to their decomposition on easily degradable organic matter, will be actived.Therefore,the goals of less volume of refuse,shorter period of stabilization, lower pollution and cost on management can be realized. When the easily degradable refuse is nearly running out by aerobic bacteria,the condition can be converted to anaerobic manner.By using the same pipe system,the generated CH4 gas will be collected to reuse energy. Through taking using of the advantages of anaerobic bacteria on consumption of hardly degradable bacteria,with the goodness of no energy consumption,the pollution can be controlled and bio-gas can be recycled. Certainly,other supplementary means,such as leachate recycling,nutrient matters and other indexes adjustment may be taken into consideration. The applying of model to simulate mechanically on aerobic and anaerobic fermentaion process can offer some useful data for the new methods applying in longer period and its improvement.

生活垃圾的填埋处理仍是当前乃至今后主要的处理处置方式。普遍采用的生活垃圾厌氧填埋技术稳定化周期长，环境污染严重，且管理成本过高。本研究将综合采用生活垃圾好氧和厌氧生物填埋两段工艺，开发一种稳定化周期短，污染小，且能资源化回收甲烷气体的新型复合式填埋工艺。在填埋初期采用好氧生物填埋，通过向填埋有机物内泵入空气，增加湿气流通和营养物质供应，激活好氧菌，加速对易降解有机物生物降解，有效减少垃圾库容，缩短填埋场稳定周期，降低污染和填埋场运营成本。在易降解有机质好氧分解基本结束后进入厌氧发酵阶段，与好氧供气利用同一管道系统进行甲烷收集。运用厌氧菌对难降解有机质分解无能耗的优势，通过渗滤液回灌、营养物质及其它工艺参数调节等手段，降低污染，同时提高厌氧阶段对难降解有机质分解速率和甲烷产率。数值模型的采用从机理上拟合好氧和厌氧阶段发酵过程，为工艺参数的改进和中后期填埋场运营提供指导性数据。

根据项目实施目的,项目组分别开展了中试填埋池平行试验,反应柱典型有机质降解好氧厌氧对比试验及数值模拟填埋池降解效果三方面工作.通过在中试填埋池对原生垃圾进行的平行试验,从氨氮,BOD5,COD和易降解有机质含量几个方面验证了所构建典型厌氧,典型好氧,和本项目拟开发的好氧-厌氧(AE-AN)两阶段复合填埋工艺的初期效果,即:相比之下,好氧和AE-AN复合填埋工艺获得了明显的降解优势.鉴于复合填埋工艺到2016年9月份停止供气,接下来既进入气温较低的微生物低活性阶段,到目前为止复合填埋工艺相较于好氧填埋工艺的技术经济优势尚无法体现出来.但是,根据远期数值模型估测和技术经济分析预测,复合填埋工艺相对于好氧填埋工艺具有明显的技术经济优势..本项目拟开发的复合填埋工艺主要立足点在于生活垃圾中易降解和中等及难降解基质分别适用于好氧和厌氧两种发酵工艺,为了对此进行更充分的证实,反应柱试验分别选取熟米饭,木屑和LDPE颗粒代表易,中,难三种基质,并在分别提供好氧和厌氧氛围,及污泥接种条件下,对比研究它们的降解效果.研究发现,尽管熟米饭在好氧和厌氧氛围下均较容易实现降解,但两种氛围对比仍能确认好氧氛围的降解优势.相对而言,木屑和LDPE则未受到好氧氛围的显著促进.这证实,本项目的立论依据是可靠的,也为远期复合填埋工艺的技术经济优势的确立奠定了基础.同时,也为复合填埋工艺的进一步研究和推广应用提供了理论支撑.