生活垃圾填埋场陈垃圾基本特性及再利用

填埋场已填埋陈垃圾具有丰富的资源 ,我国填埋量已达几千万吨。通过对上海老港生活垃圾填埋场 6年填埋龄和 1 0年填埋龄陈垃圾基本特性的测试研究 ,揭示出填埋 6年以上的陈垃圾已具有相当稳定的性状 ,原始垃圾特征已完全消失 ,开挖后没有异味 ,在组成上除部分大颗粒无机物和大块难降解有机物外 ,其余部分已腐化为类土壤物质 ,可以开采再利用。陈垃圾中类土壤部分在物理化学性质、水力学和微生物学性质上均表现出在自然条件下难以形成的、极为优良的基质特征 ,可用作污染物生物处理基质或作物培育基质。     

大型填埋场垃圾降解规律研究

在上海市老港垃圾填埋场建造了一座面积为3000m^2，高度为4m，内填生活垃圾10800t的小型卫生填埋场。对该卫生填埋场进行了40个月的监测，分析了垃圾中的总糖、总炭、挥发性物质和有机碳、生物可降解物含量（BDM）、粗纤维含量与填埋时间的关系。同时，也对1991年至1994每年4月份的填埋单元垃圾组成了分析。通过数学聚合，预测了填埋单元封场后的若干年内垃圾组成，对填埋场稳定化程度和垃圾矿化程度进行了判断。结果表明，该场的稳定化时间大约为22－23年，届时，该场的垃圾基本上达到无害化和稳定化，绝大部分可降解的有机物得到充分降解。     

生活垃圾填埋场垃圾腐殖质组成和变化规律的表征

通过分析上海老港生活垃圾填埋场填埋垃圾的腐殖质组成和光密度,考察了填埋垃圾的腐殖质组成和光学特性随填埋龄的变化规律.研究结果表明,填埋龄在1～14 a间的填埋垃圾中腐殖质组分的有机碳绝对含量的波动幅度很大,而腐殖质组分相对含量具有比较明显的变化规律,其中腐殖质总可提取率和wHA/wFA比值分别随填埋龄增加呈线性下降和上升的趋势.另一方面,填埋垃圾腐殖质光学特性研究表明,填埋垃圾可提取腐殖质和富里酸组分的E4/E6比值随填埋龄变化无明显关系,而胡敏酸的E4/E6比值则随填埋龄的增加呈线性下降趋势.因此,填埋垃圾腐殖质的总可提取率、wHA/wFA比值以及胡敏酸组分的E4/E6比值可有效地表征填埋垃圾和填埋场的稳定化进程.     

Three-stage aged refuse biofilter for the treatment of landfill leachate

A field-scale aged refuse(AR) biofilter constructed in Shanghai Refuse Landfill,containing about 7000 m3 aged refuse inside,was evaluated for its performance in the treatment of landfill leachate. This AR biofilter can be divided into three stages and can manage 50 m3 landfill leachate per day. The physical,chemical,and biological characteristics of AR were analyzed for evaluating the AR biofilter as leachate treatment host. The results revealed that over 87.8%-96.2% of COD and 96.9%-99.4% of ammonia nitrog...     

生活垃圾填埋场不同粒径陈垃圾中微生物的分布特征

用3种尺寸的方形筛筛分填埋龄为6～7a的陈垃圾,并对筛分得到的4种不同粒径垃圾中的微生物类群分布特征进行研究.研究结果表明,陈垃圾中含有非常丰富的微生物,可达到1012CFU·g-1,其数量分布随粒径的变化为:(《4mm)＞(8～25mm)＞(4～8mm)＞(＞25mm);兼氧细菌在各粒径陈垃圾微生物中占绝对优势,其可达1012CFU·g-1,其次为真菌和厌氧细菌,真菌最高可达107CFU·g-1,厌氧细菌最高可达106CFU·g-1,放线菌数量最少,但也能达105CFU·g-1;同类群的微生物在不同粒径垃圾中的分布不同,不同粒径垃圾中不同微生物类群的数量组成也不相同;兼氧细菌和真菌数量对数值与各项理化指标线性回归方程表明,2类微生物明显受到含水率、浸提氨态氮、BDM和pH的影响.     

Effect of bio-column composed of aged refuse on methane abatement – A novel configuration of biological oxidation in refuse landfill

An experimental bio-column composed of aged refuse was installed around the exhaust pipe as a new way to mitigate methane in refuse landfill.One of the objectives of this work was to assess the effect of aged refuse thickness in bio-column on reducing CH 4 emissions.Over the study period,methane oxidation was observed at various thicknesses,5 cm (small size),10 cm (middle size) and 15 cm (large size),representing one to three times of pipeline diameters.The middle and large size both showed over 90% methane conversion,and the highest methane conversion rate of above 95% occurred in the middle-size column cell.Michaelis-Menten equation addressed the methanotrophs diffusion in different layers of the bio-columns.Maximum methanotrophic activity (V max) measured at the three thicknesses ranged from 6.4 × 10 3 to 15.6 × 10 3 units,and the half-saturation value (K M) ranged from 0.85% to 1.67%.Both the highest V max and K M were observed at the middle-size of the bio-column,as well as the largest methanotrophs population,suggesting a significant efficiency of methane mitigation happened in the optimum zone with greatest affinity and methanotrophic bacteria activities.Therefore,bio-column is a potential style for methane abatement in landfill,and the aged refuse both naturally formed and artificially placed in the column plays a critical role in CH 4 emission.     

Excavation and characterization of refuse in closed landfill

Refuse in landfills becomes stabilized as organic matter in refuse degrades and soluble inorganic substances dissolve during their longterm stabilization process.In this paper,this process is also referred to as mineralization process and the resultant stabilized refuse referred to as aged refuse.Aged refuse contains a wide spectrum and huge quantity of microorganisms with strong decomposition capability for refractory organic matter present in some wastewater such as leachate.In this study,aged refuse excavated from 2 to 10 years old closed landfill compartments in Shanghai Refuse Landfill is characterized in terms of particulate distribution by screening,total nitrogen,total phosphorus,biodegradable matter.The approaches for redevelopment of both land and aged refuse in the stabilized landfills are proposed.     

Microbiological indication of municipal solid waste landfill non-stabilization

Accidental collapse resulted from unstable factors is an important technological problem to be solved in sanitary landfill. Microbiological degradation of organic matters in landfilled solid waste are an important unstable factor. A landfill reactor was thus manufactured and installed to examine quantitative and population dynamics of microorganisms during degradation of landfilled solid waste. It was showed that unstable landfill can be reflected and indicated by microbiological features such as rapidly decreased growth amount of microorganisms, no detection of fungi and actinomyces, and changing the dominant population into methanogenic bacteria and Acinotobacter.     

非正规填埋场矿化垃圾理化性质与资源化利用研究

为探索非正规垃圾填埋场矿化垃圾资源化利用问题,以广东省东莞市常平镇桥沥垃圾填埋场矿化垃圾为例,多点采集样品经人工分拣和不同粒径段筛分后,对其物理组成和化学性质进行了分析.结果表明:矿化垃圾中腐殖土主要在40mm粒径段以下,占47.3%,塑料、织物及木竹等可燃轻质垃圾主要在大于80mm粒径段,占40.1%;工程筛分粒径可选40mm,筛上物主要为可燃物,筛下物主要为腐殖土;按照有机肥堆肥腐熟标准,筛下物腐殖土基本可达到腐熟,营养物质含量达到《城市生活垃圾农用标准》(GB8172-1987)要求,但部分重金属含量超标;矿化垃圾经筛分后的轻质垃圾,热值约为6000kJ/kg,可直接进行焚烧处理,将其制备成垃圾衍生燃料(RDF)后,热值可达10000~24000kJ/kg.     

Effect of leachate recycle and inoculation on microbial characteristics of municipal refuse in landfill bioreactors

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城市生活垃圾填埋场中抗生素残留特征研究

为研究城市生活垃圾填埋场中抗生素的残留及其浓度特征,采集上海市老港填埋场中固体废弃物和渗滤液样本,采用超高效液相色谱三重四级杆质谱联用技术(UPLC-3Q-MS)检测抗生素浓度.结果显示,固体废弃物和渗滤液中四环素类、磺胺类、喹诺酮类、大环内脂类及β-内酰胺类抗生素的检出浓度范围分别为0.1~4.9μg·kg~(-1),nd~3245.0 ng·L~(-1)、nd~16.3μg·kg~(-1),nd~1360.0 ng·L~(-1)、0.2~367.5μg·kg~(-1),nd~6950.0ng·L~(-1)、LOQ~8.4μg·kg~(-1),0.3~9450.0 ng·L~(-1)及nd~2.8μg·kg~(-1),nd~293.5 ng·L~(-1).抗生素浓度在垃圾填埋场中的分布存在时空差异,填埋场1.5 m处固体废弃物中抗生素的浓度高于0.5 m处,新鲜渗滤液中抗生素浓度大于老龄渗滤液.研究结果为可今后垃圾填埋场中残留抗生素的治理提供理论依据.     

Effect of leachate recycling and inoculation on the biochemical characteristics of municipal refuse in landfill bioreactors

Activity development of key groups of enzymes involved in municipal refuse decomposition was measured in laboratory landfill bioreactors with and without leachate recycling and inoculation for about 210 days.The results showed that the enzymes(amylase,protease,cellulase,lipase and pectinase)were present in fresh refuse but at low values and positively affected by leachate recycling and refuse inoculation.The total average of cellulase activity in digesters D3 operated with leachate recycling but no inoculation,D4 and D5 operated with leachate recyling and inoculation was much higher than that in digesters D1 and D2 without leachate recycling and inoculation by 88%-127%,117%-162%and 64%-98%.The total average of protease activity was higher in digester D4 than that in digesters D1,D2,D3and D5 by 63%,39%,24%and 24%,respectively,and the positive effect of leachate recycling and inoculation on protease activity of landfilled refuse mainly was at the first two months.The total average of amylase activity was higher in digesters D3,D4 and D5 than that in digesters D1 and D2 by 83%-132%,96%-148%and 81%-129%.During the early phase of incubation,the stimulatory effect of inoculation on lipase activity was measured,but refuse moisture was the main factor affecting lipase activity of landfilled refuse.The inoculation,initial and continuous inoculation of microorganisms existing in leachate,was the mainly stimulatory factor affecting pectinase activity of landfilled refuse.     

城市污水处理厂化学强化生物除磷的试验研究

为有效解决北京某城市污水处理厂出水总磷含量较高的实际问题,通过在生物处理工艺(A2O)后端添加化学除磷强化单元的方法,依次开展了实验室试验和现场的生产性试验.实验室试验以好氧池出水为试验用水,对不同浓度梯度的聚合氯化铝(PAC)、聚合硫酸铁(PFS)、三氯化铁(FeCl3)等除磷效果进行了对比研究,并分别对其除磷机理进行了深入的探讨.试验结果表明:3种药剂中,PAC除磷效果最好,当其投加量为60mg/L,投加系数β为4.15时,出水总磷含量可小于0.5mg/L,而且药剂投加成本较低,仅为0.078元/t.现场生产性试验选取好氧池出水端为药剂投加点,对PAC的除磷效果进行现场验证.经试验测定,当PAC投加量为60mg/L,投加系数β为4.22时,污水处理厂出水总磷含量远低于0.5mg/L,符合排放要求.考虑到进水量和负荷的波动,在保证出水达标排放的前提下,为保证药剂的有效利用,通过采取针对性措施提高前端生物除磷效率及反馈投加药剂的方法,以有效减少药剂的投加量及化学污泥的排放量,达到节能减排的目的.     

生活垃圾腐殖土物化性质及资源化利用途径——以浙江省某高龄期填埋场为例

以填埋龄期23~37a、粒径<15mm腐殖土为对象,测试分析了其物质组成、理化性质和浸出液性质.测试与分析结果表明:腐殖土中粒径范围2~15mm、0.075~2mm和<0.075mm的组分分别占比42.9%~53.9%、40.9%~44.1%和5.1%~13.0%,属于细粒砂土;随着填埋龄期增加,腐殖土特征粒径d₅₀和d₁₀呈现减小趋势,比重明显增大,并在30a后趋于稳定.腐殖土中有机质含量(18.1%~19.1%,)、氮磷钾含量、浸出液pH值(7.26~8.30)及电导率(1.08~2.51mS/cm)等指标均满足国家现行《绿化用有机基质》要求.腐殖土中重金属Cu、Zn、Cd、Cr含量均超出国家现行《土壤环境质量农用地土壤污染风险管控标准(试行)》、《绿化种植土壤》和《绿化用有机基质》的标准要求,内梅罗综合污染指数高达15.48~17.95,属于重度污染类型,且重金属主要富集在粒径<2mm的细颗粒.建议将腐殖土进一步精细化筛分为粒径2~15mm与粒径<2mm两部分,针对粒径<2mm部分采用微生物诱导碳酸盐沉淀等技术,降低重金属浸出浓度.处理后的腐殖土可作为园林绿化、填埋场覆盖以及废弃矿山修复的绿化土层.     

垃圾填埋场地下水污染修复技术优选研究

结合国内外地下水污染场地的修复经验,综合考虑当地社会经济条件、地下水脆弱性、污染物特征等因素,采用层次分析法建立了修复技术优化指标体系;在此基础上运用多准则决策分析模型(MCDA)进行地下水污染修复技术优选排序,构建垃圾填埋场地下水污染修复技术筛选模型;并以湖北省某简易垃圾填埋场为例进行应用研究。结果表明:在备选的5种场地地下水修复技术(监测自然衰减技术、渗透反应格栅、多相抽提技术、抽出-处理技术、原位微生物修复技术)中,抽出-处理技术、原位微生物修复技术较为理想。综合考虑该污染场地条件、地下水污染治理要求及附近受体分布情况,得到最佳修复方案为:高污染风险区域采用抽出-处理技术和原位微生物修复技术组合;低污染风险区域采用监测自然衰减技术。     

城市生活垃圾填埋场甲烷收集效率研究

为提高垃圾填埋场CH4收集系统的收集效率,减少CH4的排放,对广州某生活垃圾填埋场CH4收集效率和填埋堆体表面CH4释放速率进行了研究.研究表明:采用US-EPA一级动力学模型计算出2010年该填埋场理论CH4产量为7.22×107m3,估算实际产量为(2.17～2.89)×107m3,实际收集量为1.75×107m3,实际收集量占估算实际产量的60.6%～80.6%.填埋作业面是填埋场主要的CH4排放源,年排放量为0.175×107m3,占实际收集量的10.0%.其中,陈垃圾作业面和新填垃圾作业面CH4的释放速率分别为4.17mol·m-·2h-1和0.29mol·m-·2h-1.     

垃圾填埋场渗滤液诱发小鼠骨髓细胞微核效应

研究了垃圾填埋场渗滤液诱发小鼠骨髓嗜多染红细胞(PCE)微核(MN)效应.结果表明,渗滤液可诱发微核的形成,且呈明确的浓度(渗滤液COD_Cr)-效应关系.在亚急性染毒条件下,渗滤液COD_Cr为10mg/L时,可诱发微核率和微核细胞率显著高于阴性对照(n=16,P<0.001);在亚慢性染毒条件下,渗滤液COD_Cr为5mg/L时,即可诱发微核率和微核细胞率显著高于阴性对照(n=16,P<0.001).这一结果从整体水平上证明了垃圾填埋场渗滤液对哺乳动物具有遗传损伤效应,同时提示可以以小鼠骨髓嗜多染红细胞微核试验结果作为渗滤液生物监测指标.渗滤液处理时间越长,引起细胞遗传损伤所需的最低浓度越低,意味着长期接触环境低浓度渗滤液污染有引起体内细胞遗传物质损伤的潜在危险.     

南昌市生活垃圾卫生填埋生命周期评价

卫生填埋法是当前我国处理城市生活垃圾的主要方式,依据生命周期评价理论及分析框架,借助eFootprint软件对南昌市卫生填埋法处理城市生活垃圾进行生命周期分析以期找出各处理过程的突出环境影响及原因并提出针对性改善建议.结果表明：卫生填埋法处理城市生活垃圾的主要环境影响类型为全球变暖（GWP）、初级能源消耗（PED）、水资源消耗（WU）、酸化（AP）、光化学臭氧合成（POFP）、生态毒性（ET）、淡水富营养化（FEP）;电力盈余作为副产品参与分配使得各环境影响类型指标潜值减小,其中最突出的是PED,其次是WU;收集运输过程最突出的环境影响类型为POFP,其次依次为ET、PED、FEP,该过程应减少柴油运输车使用,适量引用节能环保或清洁能源汽车;卫生填埋过程在垃圾处理各过程中产生的环境污染最大,该过程最突出的环境问题是AP,其次是GWP,再者是PED、FEP、ET,该过程应改善工艺以提升填埋气收集效率,采用清洁能源减少柴油使用;填埋气发电过程因填埋气发电产生盈余电力,实现能量回收后对环境的正效益,该过程应提升填埋气收集以及燃烧发电效率;渗滤液处理过程的环境影响较小,主要表现为WU和FED,需在注重节能的同时优化升级处理工艺,改善当前处置工艺存在的弊端并排除隐患.     

Methanotrophic community structure of aged refuse and its capability for methane bio-oxidation

Aged refuse from waste landfills closed for eight years was examined and found to contain rich methanotrophs capable of biooxidation for methane. Specially, community structure and methane oxidation capability of methanotrophs in the aged refuse were studied. The amount of methanotrophs ranged 61.97 103–632.91 103 cells/g (in dry basis) in aged refuse from Shanghai Laogang Landfill. Type I and II methanotrophs were found in the aged refuse in the presence of sterilized sewage sludge and only Type I methanotrophs were detected in the presence of nitrate minimal salt medium (NMS). The clone sequences of the pmoA gene obtained from the aged refuse were similar to the pmoA gene of Methylobacter, Methylocaldum, and Methylocystis, and two clones were distinct with known genera of Type I methanotrophs according to phylogenetic analysis. Aged refuse enriched with NMS was used for methane biological oxidation and over 93% conversions were obtained.     

Minimizing N_20 fluxes from full-scale municipal solid waste landfill with properly selected cover soil

Municipal solid waste landfills emit nitrous oxide(N_2O)gas.Assuming that the soil cover is the primary N_2O source from landfills, this study tested,during a four-year project,the hypothesis that the proper use of chosen soils with fine texture minimizes N_2O emissions.A full-scale sanitary landfill,a full-scale bioreactor landfill and a cell planted with Nerium indicum or Festuca arundinacea Schreb,at the Hangzhou Tianziling landfill in Hangzhou City were the test sites.The N_2O emission rates from all test sites were considerably lower than those reported in the published reports.Specifically,the N_2O emission rate was dependent on soil water content and nitrate concentrations in the cover soil.The effects of leachate recirculation and irrigation were minimal.Properly chosen cover soils applied to the landfills reduced N_2O flux.