城市生活垃圾填埋场渗滤液生化处理过程中重金属离子问题

我国对城市生活填埋场渗滤液处理技术的研究主要集中在COD与NH4 -N的去除上,对渗滤液中重金属离子的专项研究几乎未见报道.本文首先总结了国内外城市生活垃圾渗滤液中重金属的种类及浓度,在渗滤液中的存在状态,渗滤液中重金属与其他成分(有机物、氨氮)的相互作用关系,辨证分析了重金属在渗滤液生化处理过程中的有益作用和毒性,归纳了重金属在渗滤液生化处理过程中的变化规律,同时总结分析了重金属的去除技术.     

垃圾渗滤液资源化处理及超临界水气化产氢研究进展

回顾了垃圾渗滤液(简称渗滤液)末端处理,利用渗滤液生产有机肥料、燃料,回收渗滤液中氨氮和腐殖酸,厌氧发酵制沼气,生物制氢气等渗滤液资源化利用技术的研究进展;提出了超临界水气化(SCWG)技术具有气化效率高、反应速度快、气体产物中氢含量高等特点,被广泛应用于生物质制氢的研究;指出了利用SCWG技术处理渗滤液不仅能对渗滤液进行有效治理,并且能回收反应产生的氢气资源,实现渗滤液污染治理和资源回收的有机结合。     

垃圾填埋场渗滤液性质研究进展

从宏观、中观和微观三个尺度对目前垃圾填埋场渗滤液的性质、处理方法和研究手段进行了系列介绍与比较。比较结果表明．相对于宏观和微观尺度的渗滤液性质的研究,中观尺度的研究将更有助于指导渗滤液处理工艺的发展方向。     

用光催化氧化法处理垃圾渗滤液的实验研究

以城市生活垃圾渗滤液作为研究对象 ,采用悬浮态半导体催化剂对渗滤液进行处理试验。研究了ZnO TiO2复合半导体催化剂的催化活性 ,并研究了各种实验条件、影响因素及处理效果。研究表明 ,在一定的试验条件下 ,用ZnO TiO2 复合半导体催化剂处理城市垃圾渗滤液效果较好 ,可作为垃圾渗滤液的深度处理。同时得到光催化氧化法处理渗滤液的最佳试验参数。     

城市生活垃圾填埋场渗滤液生化处理过程中重金属离子问题

我国对城市生活填埋场渗滤液处理技术的研究主要集中在COD与NH4^＋-N的去除上。对渗滤液中重金属离子的专项研究几乎未见报道。本文首先总结了国内外城市生活垃圾渗滤液中重金属的种类及浓度，在渗滤液中的存在状态。渗滤液中重金属与其他成分（有机物、氨氮）的相互作用关系，辨证分析了重金属在渗滤液生化处理过程中的有益作用和毒性，归纳了重金属在渗滤液生化处理过程中的变化规律。同时总结分析了重金属的去除技术。     

国内渗滤液处理研究和应用现状

对国内卫生填埋场垃圾渗滤液处理的研究和应用现状作了综述,分别介绍了渗滤液处理的单元工艺和组合工艺的研究进展,并介绍了多个国内渗滤液处理的应用实例.     

超声/Fenton联用技术处理垃圾渗滤液中的有机物

详细研究了超声/Fenton联用技术对垃圾渗滤液中有机物的处理效果.研究内容包括:超声波频率对垃圾渗滤液色度和COD去除率的影响,超声波功率对垃圾渗滤液色度和COD去除率的影响以及Fenton试剂用量和pH值对垃圾渗滤液色度去除率和COD去除率的影响.还利用一次正交回归实验确定了超声/Fenton联用技术处理垃圾渗滤液的优化条件,并在优化条件的基础上,对超声波技术、Fenton高级氧化技术和超声/Fenton联用技术对垃圾渗滤液的处理效果进行比较研究.研究结果表明:超声/Fenton联用技术对垃圾渗滤液的色度去除率和COD去除率最高,其色度去除率接近100%,COD去除率达到73.5%.超声/Fenton联用技术处理垃圾渗滤液的优化条件是:超声频率为28 kHz,超声功率为75W,Fe2 浓度为280 mg/L,H2O2浓度为1.29×104 mg/L,pH值为2.5.超声波的频率、功率和Fenton试剂用量之间存在优化匹配值.     

北方城市垃圾渗滤液水量水质变化特征

研究了垃圾卫生填埋场渗滤液的年产量、夏季产量及其与填埋场规模、运行年限之间的关系。分析了填埋场夏季渗滤液的COD、BOD5、氨氮、p H值和BOD5/COD规律。研究结果表明,渗滤液年产量与填埋场规模、运行年限有关。渗滤液夏季产量变化规律与其相应的年产量并不一致。规模M≤100 t/d、100M≤200 t/d、200M≤500 t/d和M500 t/d的填埋场夏季渗滤液产量呈现出不同的变化特征。各填埋场的夏季渗滤液水质差别较大,COD值总体偏小,处于35.5~3 029.8 mg/L之间;BOD5值处于6.5~1 120.7 mg/L之间;64.2%的填埋场夏季渗滤液的BOD5/COD值≥0.30,可生化性较好;氨氮为21~1 273 mg/L。研究结果可为国内城市垃圾卫生填埋场渗滤液处理工作提供参考。     

回灌对垃圾填埋初期渗滤液化学需氧量的影响

通过模拟柱实验 ,研究了回灌对垃圾填埋场初期渗滤液 CODCr的影响。研究结果表明 ,模拟降雨雨水的渗入且无渗滤液回灌的参照柱 ,其渗滤液出水 CODCr最高 ,一般在 70 0 0 0 mg/L 左右 ;模拟渗滤液原液回灌 ,从第 4周起因脂肪酸的积累导致渗滤液的 p H低于 6,从而抑制了微生物的生化反应 ;模拟好氧生物处理后渗滤液的回灌 ,能加速垃圾层 CODCr的溶出和甲烷化阶段的建立 ,且此时渗滤液的 CODCr变化规律符合指数方程 ;当垃圾层建立甲烷化阶段后 ,回灌 CODCr在 2 0 0 0 0 m g/L 左右的渗滤液 ,仍可促使垃圾中有机物迅速转化为气态物     

夏季潮滩对上海老港垃圾填埋场渗滤液氮、磷净化效果研究

垃圾填埋产生的渗滤液造成的环境污染问题El益严重。采用自然湿地对垃圾渗滤液净化有诸多优点,而相关的研究较少。根据渗滤液的不同浓度和不同滞留时间的净化效果不同,采用实验室模拟和培养的方法来研究老港垃圾填埋场附近潮滩对垃圾渗滤液营养盐N、P的净化效果。研究发现：夏季老港中、低潮滩在较短滞留时间（6h）内对各浓度渗滤液中N、P的净化效果不明显,而在较长滞留时间内（96h）中、低潮滩对各浓度渗滤液净化效果明显,净化后污水中N、P含量可达到排放标准;垃圾渗滤液质量分数为5％时,潮滩对N、P的净化效果最为明显。     

Comparison of Laboratory Batch Methods and Large Columns for Evaluating Leachate from Monofilled Solid Wastes

Analyte concentrations in aqueous leachates from polyethylene tanks filled with five different solid wastes were compared with those in extracts from five laboratory batch procedures. Solid wastes used in the study included: electroplating sludge, electric arc furnace dust, paint Incinerator ash, mine tailings, and municipal refuse incinerator ash. Batch extraction procedures used to extract the solid wastes Included: Monofilled Waste Extraction Procedure (MWEP), U.S. EPA Extraction Procedure (EP), Ham Procedure C (HAM-C), Acetate Buffer Extraction Procedure (ABEP), and Saturated Paste Procedure (PASTE).

Analyte concentrations in leachate from the large columns were reproducible and characteristic of each solid waste. In most Instances, analytes in column leachate reached a peak concentration at a liquld-to-solid ratio of 1:1 followed by a gradual to rapid decrease with continued leaching. Analyte concentrations found in large column leachate were related qualitatively to those found in extracts from the batch procedures which used delonlzed water as the extraction medium (i.e., MWEP, HAM-C, and PASTE). Batch extraction procedures using leaching medium containing acetic acid (I.e., EP) or sodium acetate buffer (i.e., ABEP) generally did not reflect analyte concentrations in leachate from the large columns. These results suggest that batch extraction procedures using acetic acid or acetate buffer are less effective for assessing the teachability of monofilled wastes than extraction methods using deionized water as the extraction fluid.     

Attenuation of landfill leachate by UK Triassic sandstone aquifer materials: 2. Sorption and degradation of organic pollutants in laboratory columns

The sorption and degradation of dissolved organic matter (DOM) and 13 organic micropollutants (BTEX, aromatic hydrocarbons, chloro-aromatic and -aliphatic compounds, and pesticides) in acetogenic and methanogenic landfill leachate was studied in laboratory columns containing Triassic sandstone aquifer materials from the English Midlands. Solute sorption and degradation relationships were evaluated using a simple transport model. Relative to predictions, micropollutant sorption was decreased up to eightfold in acetogenic leachate, but increased up to sixfold in methanogenic leachate. This behaviour reflects a combination of interactions between the micropollutants, leachate DOM and aquifer mineral fraction. Sorption of DOM was not significant. Degradation of organic fractions occurred under Mn-reducing and SO₄-reducing conditions. Degradation of some micropollutants occurred exclusively under Mn-reducing conditions. DOM and benzene were not significantly degraded under the conditions and time span (up to 280 days) of the experiments. Most micropollutants were degraded immediately or after a lag phase (32–115 days). Micropollutant degradation rates varied considerably (half-lives of 8 to >2000 days) for the same compounds (e.g., TeCE) in different experiments, and for compounds (e.g., naphthalene, DCB and TeCA) within the same experiment. Degradation of many micropollutants was both simultaneous and sequential, and inhibited by the utilisation of different substrates. This mechanism, in combination with lag phases, controls micropollutant degradation potential in these systems more than the degradation rate. These aquifer materials have a potentially large capacity for in situ bioremediation of organic pollutants in landfill leachate and significant degradation may occur in the Mn-reducing zones of leachate plumes. However, degradation of organic pollutants in acetogenic leachate may be limited in aquifers with low pH buffering capacity and reducible Mn oxides. Contaminants in this leachate present a greater risk to groundwater resources in these aquifers than methanogenic leachate.     

Cell cycle stage specific application of municipal landfill leachates to assess the genotoxicity in root meristem cells of barley (Hordeum vulgare)

Municipal solid wastes (MSW) are unavoidable sources of environmental pollution. Improper disposal of municipal waste results in the leaching of toxic metals and organic chemicals, which can contaminate the surface and ground water leading to serious health hazard. In this study, the toxic effects of the leachate prepared from municipal solid waste samples were examined in root meristem cells of barley (Hordeum vulgare L.) at various stages of cell cycle, i.e., G₁, S, and G₂. Seeds of barley were exposed to 2.5, 5, and 10 % of leachates in soil and aqueous media in 48 h at different cell cycle stages. The physicochemical data of the present study revealed that municipal solid waste leachate contains high amount of heavy metals, which significantly affected growth and physiological activities of barley. Significant inhibition in hypocotyl length, germination, and mitotic index were observed at all concentration of leachate treatment. Induction of chromosomal aberrations (CA’s) and micronuclei (MN) formation were also observed with different concentrations of leachate treatment at 7, 17, and 27 h of presoaking durations, which falls in G₁, S, and G₂ phase of the cell cycle, respectively. Also, exposure of leachate at S phase of the cell cycle had significant effects in barley through chromosomal aberration and micronuclei formation.     

Estrogenic and dioxin-like potency in each step of a controlled landfill leachate treatment plant in Japan

The estrogenic activity (by E-screen bioassay), the concentrations of PCBs, PCDDs/PCDFs (and their resulting toxicity equivalents, TEQ) and several endocrine disrupting chemicals (EDCs: e.g., bisphenol A, nonylphenol, Butyl benzylpthalate (BBP), di-n-butylphthalate (DBP), 17alpha-ethynyl-estradiol or 4-octylphenol) have been analyzed from leachates of each step (before treatment, after biodegradation/sedimentation and after charcoal treatment) of a controlled landfill leachate treatment plant. The comparison of the effluent of the examined landfill leachate treatment plant with water from a nearby river in this study indicated no additional dioxin-like (e.g., TEQ: 0.027 compared to 1.01 pg TEQ/l; PCBs: 1.2 compared to 3.9 ng/l) or estrogenic impact (2.8 compared to 3.5 ng estradiol equivalents EE/l; analyzed by E-screen bioassay) from the leachate treatment plant into the surrounding water environment. The impact of dioxin-like compounds from uncleaned leachates into the final cleaned effluents could be sufficiently reduced by the leachate treatment plant for PCDDs (75%), PCDFs (62%), dioxin-like PCBs (97%), and the sum of TEQ (78%). The leachate treatment plant also achieved a reduction of the estrogenic activity as determined by E-screen (from 4.8 to 2.8 ng EE/l = 42%), by GC/MS for bisphenol A (>96% and nonylphenol (>98%) or by ELISA for estradiol (>80%). Additionally, for the validation of the E-screen, five known endocrine disrupting chemicals (EDCs: bisphenol A, BBP, DBP, 17 alpha-ethynyl-estradiol, 4-octylphenol) were analyzed. The EC50 values and estradiol equivalents factors (EEFs) for the five EDCs determined in this study were comparable to previously published data. The combined biological and chemical trace analysis data have provided valuable information on the relative contribution of natural, synthetic, and non-steroidal anthropogenic chemicals to the estrogenic and dioxin-like activity in leachates from a wastewater treatment plant, and water from a nearby river.     

生活垃圾填埋场渗滤液处理技术研究

根据处理工艺原理的不同 ,分别介绍生化和物化处理技术、膜处理技术、土地处理技术和蒸发处理技术等处理工艺研究与应用的进展情况 ,同时根据我国填埋场渗滤液的产生特点和处理处置现状 ,展望了我国渗滤液处理工艺的发展趋势。     

A comparative examination of MBR and SBR performance for the treatment of high-strength landfill leachate

The management of landfill leachate is challenging, with relatively limited work targeting high-strength leachate. In this study, the performance of the membrane bioreactor (MBR) and sequencing batch reactor (SBR) technologies are compared in treating high-strength landfill leachate. The MBR exhibited a superior performance with removal efficiencies exceeding 95% for BOD5, TN, and NH₃ and an improvement on SBR efficiencies ranging between 21 and 34%. The coupled experimental results contribute in filling a gap toward improving the management of high-strength landfill leachate and providing comparative guidelines or selection criteria and limitations for MBR and SBR applications.

ImplicationsWhile the sequencing batch reactor (SBR) technology offers some flexibility in terms of cycle time and sequence, its performance is constrained when considering landfill leachate associated with significant variations in quality and quantity. Combining membrane separation and biodegradation processes or the membrane bioreactor (MBR) technology improved removal efficiencies significantly. In the context of leachate management using the MBR technology, more efforts have targeted low-strength leachate with limited attempts at moderate to high strength leachate. In this study, the SBR and MBR technologies were tested under different operating conditions to compare and evaluate their feasibility for the management of high-strength leachate from a full-scale operating landfill. Such a comparison has not been reported for high-strength leachate.     

AMMONIA REMOVAL FROM COMPOST LACHATE USING ZEOLITE. II. A STUDY USING CONTINUOUS FLOW PACKED COLUMNS

Bench-scale packed zeolite columns were set up and operated to investigate the continuous removal of ammonium ions from compost leachate. The effects of hydraulic retention time (HRT), and particle size of the zeolite on the ammonia adsorption capacity were studied. For both the coarse particle and the powdered zeolite columns, higher ammonia removal efficiencies were achieved with longer HRT (i.e., lower influent flow rate) tests. At the same HRT, ammonia removal efficiencies from tests with powdered zeolite were generally 20% higher than tests with the coarse particle zeolite. A HRT of 6 hours was found appropriate for efficient ammonia removal, and an operating capacity of 1.31 mg N/g zeolite was obtained. Over 98% of the ammonia input from the influent was consistently removed for over 5 bed volumes (BV) of compost leachate flowing through the zeolite column. Zeolite proved to have a great potential as a medium for ammonia removal in treating composting leachate.     

Ammonia removal from compost leachate using zeolite. II. A study using continuous flow packed columns

Bench-scale packed zeolite columns were set up and operated to investigate the continuous removal of ammonium ions from compost leachate. The effects of hydraulic retention time (HRT), and particle size of the zeolite on the ammonia adsorption capacity were studied. For both the coarse particle and the powdered zeolite columns, higher ammonia removal efficiencies were achieved with longer HRT (i.e., lower influent flow rate) tests. At the same HRT, ammonia removal efficiencies from tests with powdered zeolite were generally 20% higher than tests with the coarse particle zeolite. A HRT of 6 hours was found appropriate for efficient ammonia removal, and an operating capacity of 1.31 mg N/g zeolite was obtained. Over 98% of the ammonia input from the influent was consistently removed for over 5 bed volumes (BV) of compost leachate flowing through the zeolite column. Zeolite proved to have a great potential as a medium for ammonia removal in treating composting leachate.     

物理化学法处理垃圾填埋场渗滤液的研究进展

本文介绍了渗滤液的特性 ,指出物理化学法是渗滤液处理过程中不可缺少的环节。总结了物理化学法处理渗滤液的进展状况 ,并提出了物理化学法处理渗滤液存在的问题及未来发展趋势