垃圾堆体高度对渗滤液回灌处理的影响

通过模拟试验研究了垃圾填埋场渗滤液分别回灌到不同高度的垃圾柱之后，柱内的有机污染物降解变化规律。结果表明：回灌处理法对有机物有较好的处理效果，对回灌渗滤液中有机物的去除效果随垃圾堆体高度的增加而增加；单位矿化垃圾可承受的有机污染负荷有一限值，当在一定时间内因回灌而进入垃圾堆体中的有机污染负荷超过这一限值时，渗滤液回灌处理系统将遭到破坏且不易恢复。     

城市垃圾渗滤液处理工艺综述

文章介绍了垃圾渗滤液的产生和特点,分析了国内外垃圾填埋场渗滤液的处理工艺,包括生化法、物化法和土地处理法,着重提出回灌法,并建议了渗滤液的治理方向。     

生物反应器填埋场中水平沟回灌渗滤液非饱和-饱和渗流分析

水平沟回灌是生物反应器填埋场中渗滤液回灌的主要模式之一，为研究水平沟回灌时生物反应器填埋场中渗滤液的非饱和-饱和运移规律，垃圾体的饱和与非饱和区域采用不同水流控制方程，饱和区域的水流控制方程采用饱和Richards方程，对垃圾体非饱和区域，由质量守恒原理，以修正的Darcy定理为基础，结合Elagroudy等提出的垃圾体沉降模型，建立了考虑垃圾体沉降的非饱和渗滤液运移控制方程。基于建立的考虑沉降特性的二维非饱和-饱和水平沟回灌计算模型，研究了水平沟回灌时渗滤液在生物反应器填埋场中的运移规律，提出水平沟回灌系统的设计方法。     

浓缩液回灌对垃圾填埋体水位及稳定性的影响

成都长安填埋场渗滤液反渗透处理工艺日产260 t浓缩液,拟在填埋场进行回灌处理,回灌工程实施前需评估回灌工程对垃圾填埋体稳定性的影响.在该填埋场工程地质与水文地质勘查结果的基础上,利用GMS软件开展了垃圾填埋体非饱和一饱和三维渗流分析,模拟和预测了浓缩液回灌前后填埋体内渗滤液水位变化.基于渗流分析结果,利用Slope/...     

准好氧填埋场垃圾渗滤液全循环回灌处理研究

将模拟准好氧填埋场垃圾渗滤液进行全循环回灌处理，考察了不同回灌条件对渗滤液稳定化进程的影响。结果表明，不同回灌条件下垃圾渗滤液具有基本相同的稳定化进程，COD和BOD5值均经历了快速下降、稳定下降和缓慢下降3个时期；而氨氮浓度则是先升高后降低。每日回灌总量和回灌频率是影响渗滤液稳定化进程的主要因素：在一定范围内，二者取值越大则渗滤液的稳定化程度越高。     

考虑垃圾体沉降的生物反应器填埋场 渗滤液回灌运移规律

生物反应器填埋场在渗滤液的回灌过程中,垃圾体会产生较大的沉降变形,这主要是由于填埋体的自重和生物降解所致。由于沉降变形会导致生物反应器填埋场中垃圾体的孔隙比减小,孔隙比的减小会影响垃圾体的渗透系数和填埋场所能容纳的渗滤液量。为了研究考虑垃圾体沉降的生物反应器填埋场渗滤液回灌运移规律,根据质量守恒原理,以修正的Darcy定理为基础,结合Elagroudy等人提出的沉降模型,建立了考虑垃圾体沉降的生物反应器填埋场渗滤液回灌的计算模型,应用该模型研究了非饱和条件下渗滤液在生物反应器填埋场中的运移规律,分析了回灌强度、垃圾体初始孔隙比、初始含水率和组成成份等参数变化对垃圾体含水率和填埋场单位表面积回灌量的影响规律。     

采用垃圾准好氧填埋消除酸积累现象的试验研究

针对垃圾厌氧填埋渗滤液在直接回灌初期会出现严重的酸积累现象,分析研究了垃圾准好氧填埋与厌氧填埋的渗滤液直接回灌后的出水水质,发现采用准好氧垃圾填埋的体系内所含挥发性脂肪酸量和COD量比厌氧填埋柱低得多,不存在酸积累现象;从整个降解过程看,准好氧填埋加快了COD的降解速率,加速了垃圾体的稳定化进程;另外,环境温度对垃圾体的降解速率影响很大,较高的温度能够加速垃圾体的降解速度.     

加速填埋场稳定化工艺--渗滤液回灌

在分析渗滤液自身回灌存在问题的基础上 ,对目前出现的渗滤液循环 (间接 )回灌工艺进行了综述 ,并对有渗滤液处理设施的填埋场和新建填埋场渗滤液回灌的运行方式进行了探讨     

准好氧填埋垃圾渗滤液全循环处理的影响因素研究

对准好氧垃圾填埋所产生的垃圾渗滤液进行全循环处理,考察了水力负荷和回灌次数对渗滤液除污效果的影响。正交试验结果表明,水力负荷是影响渗滤液中污染物去除效果的关键因素,回灌次数则为次要因素;较优的水力负荷和回灌次数分别为15.9 L/(m2.d)和3次/d,此时对渗滤液中COD、BOD5、NH4+-N的去除率分别为99.3%、99.7%和98.7%。     

老龄化垃圾填埋场渗滤液全量化处理工程实例

老龄化填埋场渗滤液氨氮浓度高、可生化性差、C/N比失调，以某老龄化垃圾填埋场渗滤液和垃圾焚烧厂渗滤液协同处理工程为例，详述两种渗滤液全量化处理系统。填埋场渗滤液设计规模1 500 m³/d，焚烧厂渗滤液设计规模500 m³/d，采用“厌氧系统+两级A/O+外置式超滤+纳滤+反渗透”处理工艺，纳滤浓缩液采用“物料膜减量化+臭氧氧化”处理工艺，反渗透浓缩液采用“DTRO减量化+浸没燃烧蒸发”处理工艺。工程投资一类费3.6亿元，运行成本101.20元/m³。项目建成运行至今，出水稳定达到《生活垃圾填埋场污染控制标准》(GB 16889—2008)表2标准。通过两种渗滤液的协同处理，可减少碳源投加量，节省运行成本，同时实现渗滤液全量化处理，浓缩液不外排。     

竖井抽水下垃圾填埋场渗滤液运移规律研究

城市固废由于组成成分的多样性及分层填埋等原因,导致渗滤液运移存在明显的优先流及各向异性现象。在成都某填埋场开展多口竖井抽水及水位恢复试验,同时结合高密度电法技术(ERT)现场大尺度研究渗滤液分布及运移规律。多口竖井水位恢复试验显示填埋体内渗滤液运移具有明显的不均质性,表现为同一填埋场不同位置的竖井抽排性能差异较大,竖井周围垃圾渗透系数值分布范围为2.35×10-5~3.90×10-4 cm/s。竖井抽水下周围监测井的水位异常变化表明渗滤液补给存在明显优先流特征。ERT监测渗滤液抽水及回灌过程中堆体内电阻率变化,进一步揭示了现场渗流存在显著的各向异性和优先流特征,主要渗流路径与水平向呈0~30°。     

折光率仪快速测定盐渍土总盐含量的方法研究

建筑面临的腐蚀现象中盐害问题最突出。为快速、准确测定总盐含量,研究了折光率仪检测盐渍土总盐含量的方法。选取甘肃河西地区58个土样为研究对象,制备了不同土水比浸出液,使用折光率仪测定浸出液的折光率。建立了土壤总盐含量与不同土水比浸出液折光率之间的相关性曲线。结果表明,土壤总盐含量与不同土水比浸出液折光率之间呈显著正相关,其中,土壤总盐含量与土水比1:1浸出液折光率的相关性最紧密。同时,提出了一种通过测定浸出液折光率,由建立的相关性方程测定土壤总盐含量的方法。     

沥青中环境有害组分浸出影响因素研究

沥青在路面、屋顶以及管道内部的应用决定沥青和水具有接触的机会,这使得沥青中的组分浸出并对水环境造成危害。对影响沥青组分浸出的4个因素的研究表明,浸提液COD值随浸出时间的延长而增加,且沥青经SBS改性和氧化后,浸提液COD值较基质沥青有所增加。随着温度升高,沥青组分的浸出量增大,但温度对针入度小的沥青组分的浸出量影响较小。沥青的浸提性能受NaCl的影响也不同,而沥青经改性和氧化后其浸提液COD值变小。酸性环境对沥青组分的浸出性能影响较大,而碱性环境几乎不对其造成影响。根据沥青来源不同,浸提性能受pH值的影响也不同,而沥青经SBS改性后浸提液COD值相对基质沥青有所增加,氧化沥青则有所降低。     

Removal of bisphenol A and 17α-ethinyl estradiol from landfill leachate using single-walled carbon nanotubes

In this study, the adsorption of bisphenol A (BPA) and 17α-ethinyl estradiol (EE2) from landfill leachate onto single-walled carbon nanotubes (SWCNTs) was investigated. Different leachate solutions were prepared by altering the pH, ionic strength, and dissolved organic carbon (DOC) in the solutions to mimic the varying water conditions that occur in leachate during the various stages of waste decomposition. The youngest and oldest leachate solutions contained varying DOC and background chemistry and were represented by leachate Type A (pH = 5.0; DOC = 2500 mg/L; conductivity = 12,500 μS/cm; [Ca²⁺] = 1200 mg/L; [Mg²⁺] = 470 mg/L) and Type E (pH = 7.5; DOC = 250 mg/L; conductivity = 3250 μS/cm; [Ca²⁺] = 60 mg/L; [Mg²⁺] = 180 mg/L). These solutions were subsequently combined in different ratios to produce intermediate solutions, labeled B-D, to replicate time-dependent changes in leachate composition. Overall, a larger fraction of EE2 was removed as compared to BPA, consistent with its higher log K_OW value. The total removal of BPA and EE2 decreased in older leachate solutions, with the adsorptive capacity of SWCNTs decreasing in the order of leachate Type A > Type B > Type C > Type D > Type E. An increase in the pH from 3.5 to 11 decreased the adsorption of BPA by 22% in young leachate and by 10% in old leachate. The changes in pH did not affect the adsorption of EE2 in the young leachate, but did reduce adsorption by 32% in the old leachate. Adjusting the ionic strength using Na⁺ did not significantly impact adsorption, while increasing the concentration of Ca²⁺ resulted in a 12% increase in the adsorption of BPA and a 19% increase in the adsorption of EE2. DOC was revealed to be the most influential parameter in this study. In the presence of hydrophilic DOC, represented by glucose in this study, adsorption of the endocrine disrupting compounds (EDCs) onto the SWCNTs was not affected. In the absence of SWCNTs, hydrophobic DOC (i.e., humic acid) adsorbed 15-20% of BPA and EE2. However, when the humic acid and SWCNTs were both present, the overall adsorptive capacity of the SWCNTs was reduced. Hydrophobic (π-π electron donor-acceptor) interactions between the EDCs and the constituents in the leachate, as well as interactions between the SWCNTs and the EDCs, are proposed as potential adsorption mechanisms for BPA and EE2 onto SWCNTs.     

Natural attenuation and characterization of contaminants composition in landfill leachate under different disposing ages

Chemical Oxygen Demand (COD) composition in landfill leachate would vary as the disposal time extended. Leachates with different ages were collected from Laogang Refuse Landfill of Shanghai, the largest landfill in China with a placement scale of 7600 t refuse per day. To characterize COD composition in leachate, samples were size-fractioned into suspended fractions (> 0.45 μm), colloid fraction (0.45 μm < fraction < 1 K Da MW) and dissolved fractions (< 1 KDa MW) based on the molecular weight distribution. The fractions < 0.45 μm (including colloid fraction and dissolved fractions) in leachate were further divided into 6 fractions, i.e. hydrophobic bases (Ho-base), hydrophobic acids (Ho-acid), hydrophobic neutral (Ho-neutral), hydrophilic bases (Hi-base), hydrophilic acids (Hi-acid) and hydrophilic neutral (Hi-neutral). It was found that the ratio of TOC/TC in leachate decreased over time, indicating that the percentage of organic matters in leachate decreased as the disposal time extended. It was also observed that the hydrophobic fraction accounted to about 50% of the total matters presented in the fraction < 0.45 μm of all leachate samples. The main components in < 0.45  μm fraction were the Ho-acid, Hi-acid and Hi-base fractions. The percentage of Ho-acid in leachate decreased from 60.8% (2 a) to 43.2% (12 a). In addition, leachate with different ages was categorized into 3 phases according to the results of Principle component analysis (PCA). TOC/COD ranges of leachate in periods I, II and III were 40-54.6%, 16.9-41.3% and 10-38.9%, respectively, indicating that the COD contribution of non-carbon reduction substances increased over time in leachate. Hence, the corresponding landfill leachate treatment process should be modified according to the leachate characterization. The results obtained in this study might provide the important information for modeling, design, and operation of landfill leachate treatment systems.     

Removal of non-biodegradable organic matter from landfill leachates by adsorption

Leachates produced at the La Zoreda landfill in Asturias, Spain, were recirculated through a simulated landfill pilot plant. Prior to recirculation, three loads of different amounts of Municipal Solid Waste (MSW) were added to the plant, forming in this way consecutive layers. When anaerobic digestion was almost completed, the leachates from the landfill were recirculated. After recirculation, a new load of MSW was added and two new recirculations were carried out. The organic load of the three landfill leachates recirculated through the anaerobic pilot plant decreased from initial values of 5108, 3782 and 2560 mg/l to values of between 1500 and 1600 mg/l. Despite achieving reductions in the organic load of the leachate, a residual organic load still remained that was composed of non-biodegradable organic constituents such as humic substances. Similar values of the chemical oxygen demand (COD) were obtained when the landfill leachate was treated by a pressurised anoxic-aerobic process followed by ultrafiltration. After recirculation through the pilot plant, physico-chemical treatment was carried out to reduce the COD of the leachate. The pH of the leachate was decreased to a value of 1.5 to precipitate the humic fraction, obtaining a reduction in COD of about 13.5%. The supernatant liquid was treated with activated carbon and different resins, XAD-8, XAD-4 and IR-120. Activated carbon presented the highest adsorption capacities, obtaining COD values for the treated leachate in the order of 200mg/l. Similar results were obtained when treating with activated carbon, the leachate from the biological treatment plant at the La Zoreda landfill; in this case without decreasing the pH.     

Identification of organic compounds in leachate from a waste tip

Two different types of leachate from a municipal waste tip have been analyzed. The first type of leachate was collected from a waste tip in the acidification stage. The organic load of this leachate was high and consisted mainly of free volatile acids (over 95% of the TOC). Volatile amines and ethanol were also present (0.8 and 0.7% of the TOC respectively). The leachate was extracted with hexane and the extract was analyzed with infrared and nuclear magnetic resonance spectroscopy and a gas chromatograph-mass spectrometer combination. In the extract alcohols, hydrocarbons, esters, terpenes and phthalates have been identified. High molecular weight compounds were present only in a low concentration.The second type of leachate was collected from a waste tip in the methane fermentation stage. The organic load was relatively low. An important part of the organics was identified as high molecular weight compounds. About 32% of the organic carbon consisted of compounds with a molecular weight over 1000. Acids, amines and alcohols could not be detected. This means that the organic compounds present were end products of degradation processes.Furthermore there was a remarkable difference in heavy metal content between the two types of leachate.     

生活垃圾渗滤液污染砂土电阻率法量化检测研究

为分析电阻率法对生活垃圾渗滤液污染区边界和污染程度量化检测能力,在室内模拟渗滤液渗漏污染过程,分别利用二维,三维电阻率映像法和电极探杆法对污染过程进行检测.检测结果显示,土层被渗滤液污染后,在二维和三维视电祖率剖面图中均表现为低阻异常区.异常区边界和污染区边界具有对应关系,并随渗滤扩散范围和污染程度变化而改变.电极探杆法测量电阻率值和污染土中的渗滤液含量具有对应关系,基于建立的Archie型公式可反算求取土体中污染物含量,计算相对误差低于10%.基于电测结果的渗滤液含量求取过程需开展渗滤液稀释过程的电阻率测试试验和不同含水饱和度土样电阻率测试试验以确定相关参数.     

垃圾填埋场腾发覆盖系统控制渗滤效果的研究

腾发覆盖垃圾填埋系统(ET Landfill)利用覆盖层土壤的储水能力及植被的腾发作用对进入覆盖层的降水进行调节,达到控制渗滤的目的.通过对不同覆盖层结构和植被组合的腾发覆盖系统的水均衡动态进行试验研究,探讨了不同组合条件下的土壤水分动态过程和渗滤控制效果.结果表明,相对于无植物覆盖系统,腾发覆盖系统能够有效地调节覆盖土层的储水量,减少垃圾填埋场的渗滤液.在有植物覆盖的各组试验中,种植灌木为主60 cm覆盖土层的渗滤控制效果最好,而完全种植草本植物40 cm覆盖层的控制效果最差.