利用填埋气体去除渗滤液中成垢离子的化学机理研究

为防治渗滤液输送管道结垢,本文提出了在渗滤液进入输送管道前,利用填埋气体预先去除其中成垢离子后再进行输送的思路.本文采取室内模拟实验的方式,研究渗滤液中成垢离子(钙、镁离子)去除率的控制因子,如:模拟填埋气体(N2∶ CO2比例=1∶1)的进气速率、渗滤液pH及系统温度,并分析了各因子引起去除率发生变化的化学机理.研究发现,进气速率越小,渗滤液pH越高,系统温度越低,渗滤液中成垢离子的去除率越高.该研究为工程上利用填埋气体去除渗滤液中成垢离子提供了理论依据,具有一定现实意义.     

电解法处理城市生活垃圾渗滤液的研究

本文采用电解氧化法对垃圾渗滤液进行了预处理和深度处理研究.实验结果表明:电解氧化过程中,NH3-N优先于COD被氧化去除.当电流密度较小时,用电解法对垃圾渗滤液进行预处理,垃圾渗滤液中COD、NH3-N的去除效率很低,增大电流密度有助于增强电解效果,当电流密度为50.0mA/cm2时,电解5小时COD去除50%,氨氮去除100%.用电解法对垃圾渗滤液进行深度处理,电流密度较小时,渗滤液中COD、NH3-N即可呈现稳定降解的趋势.     

垃圾渗滤液水质特性研究进展

垃圾渗滤液已被公认为是高风险高污染废水,对地下水与地表水具有极大的潜在危害性。由于渗滤液具有高污染、水质水量差异大、难控等特点,使得其有效处理十分棘手。近年来国内外对渗滤液的研究十分广泛,本文结合国内外渗滤液相关研究中水质特性相关部分,从渗滤液的一般特性,溶解性有机质及危险物质等方面对渗滤液水质进行阐述,有助于深入了解渗滤液水质及其变化规律,从而为渗滤液的有效处理提供理论依据。     

渗滤液回灌在实际应用中应注意的问题

本文介绍了垃圾填埋场渗滤液回灌的机理、优缺点,“干填埋”与“湿填埋”之间的区别。渗滤液回灌可增加填埋废物的含水率,加快垃圾的降解速率,减少渗滤液的处理时间,提高填埋气中甲烷的含量,加速填埋场稳定化进程。鉴于以上这些优点,渗滤液回灌作为一种渗滤液处理方式将会有极大的应用前景。但在实际应用中回灌的渗滤液容易泄漏而导致地下水污染,这是影响渗滤液回灌广泛应用的主要原因。为了避免使地下水受污染,本文总结和分析了渗滤液回灌在实际应用中应注意的问题。     

垃圾渗滤液生化物化综合处理技术

正由中钢集团武汉安全环保研究院有限公司开发的垃圾渗滤液生化物化综合处理技术,适用于垃圾填埋场、焚烧厂渗滤液处理。主要技术内容一、基本原理针对垃圾渗滤液水质情况,采用"预处理+生物处理+深度处理组合工艺"。经收集的垃圾渗滤液先采用混凝沉淀、氨吹脱(氨浓度高的填埋场渗滤液)等方式,去除其中大量污染物及高浓度的氨,同时调节水质的pH值等参数使其符合后续生化处理。预处理后的渗滤液经厌氧、好氧生物处理,进一步去除COD、BOD、SS、氨氮     

城市垃圾填埋场渗滤液处理工艺综述

城市垃圾对环境的影响越来越严重,垃圾填埋导致垃圾渗滤液的大量产生,渗滤液中含有大量的有机物、大量的病菌、病毒、寄生虫等以及一些有毒有害的物质,若渗滤液不加以妥善处理、肆意排放,必将对地下水、地表水构成严重威胁,因此垃圾渗滤液的有效处理就成为一个亟待解决的问题。本文对城市垃圾填埋场渗滤液的处理工艺进行了分析和探讨,介绍了国内外垃圾渗滤液处理的主要技术,包括土地处理法、生物法和物化法,并对电解法处理垃圾渗滤液进行了详细的介绍。     

垃圾填埋场渗滤液处理方法及其分析

垃圾渗滤液的处理是垃圾填埋场设计、运行和管理中非赏关键而又难以解决的问题。本文结合国内外大量的工程实例,介绍了各种渗滤液处理方法,分析了各方法的特点和应用范围,指出了渗滤液处理研究的方向。     

城市垃圾卫生填埋场渗滤液处理措施可行性论证中应注意的几个问题

卫生填埋场渗滤液处理措施的可行性论证是此类项目环评中的重点和难点,由于现有渗滤液水质指标不能充分反映渗滤液的特点,渗滤液达标处理工艺尚不完善,以及渗滤液的最终去向问题等,使得渗滤液处理措施可行性的论证较为困难。本文就切身的体会,依托已完成的几个垃圾卫生填埋场的环境影响评价工作,针对渗滤液处理措施可行性论证中应注意的几个问题作浅要的论述。     

GC-MS法测定垃圾填埋场渗滤液中的有机污染物

采用GC-MS联用技术对深圳市两个垃圾填埋场（A和B）渗滤液中的有机污染物进行分析。垃圾场A是简易生活垃圾填埋场,垃圾场B是生活垃圾焚烧底渣填埋场。垃圾场A渗滤液中COD、TOC、NH3-N、NO3^--N等污染指标的浓度比垃圾场B渗滤液高一个数量级。两个垃圾填埋场渗滤液中分别检测出主要有机物72种和57种,其中含有大量难降解有机物,如酚类、胺类、杂环类物质。两个垃圾填埋场渗滤液中有机物组分的相对含量不同,渗滤液A中酚类物质含量最高,渗滤液B中有机物多为长链烷烃。     

小城镇生活垃圾填埋渗滤液脱氮治理研究

本文以内地驻马店市所辖的新蔡、西平、泌阳、遂平、正阳、平舆等六个县级小城镇生活垃圾填埋渗滤液为研究对象,采用鸟类石化学沉淀法治理渗滤液中的氨氮,效果理想,经济合理,为内地欠发达地区小城镇生活垃圾填埋渗滤液的脱氮研究积累了一定的经验。     

填埋期模拟准好氧填埋场的渗滤液水质特征

采用室内试验,模拟填埋期回灌型准好氧填埋场垃圾渗滤液水质变化特征。结果显示,新鲜垃圾的定期填入使渗滤波水质产生明显波动,其主要水质指标（COD、NH3-N等）不存在如非填埋期渗滤液水质指标持续下降的变化规律,表明即使对于回灌型准好氧填埋场,当其已填埋垃圾规模较小时,其处理渗滤液的能力和抵御新填入垃圾干扰的能力均是十分有限的。本研究有助于填埋期垃圾渗滤液的合理回灌。     

应用反渗透技术处理垃圾填埋场渗滤液

垃圾填埋场渗滤液属于高浓度氨氮废水,其水量、水质特性变化大,成分复杂,因此较难处理。反渗透分离技术能有效截留垃圾渗滤液中溶解态的有机和无机污染物。采用三级反渗透处理垃圾渗滤液工艺处理后的出水水质,能够满足《生活垃圾填埋污染控制标准》（DB16889-2008）要求,并把渗滤液浓缩液回灌于填埋场。     

The effects of leachate recirculation with supplemental water addition on methane production and waste decomposition in a simulated tropical landfill

In order to increase methane production efficiency, leachate recirculation is applied in landfills to increase moisture content and circulate organic matter back into the landfill cell. In the case of tropical landfills, where high temperature and evaporation occurs, leachate recirculation may not be enough to maintain the moisture content, therefore supplemental water addition into the cell is an option that could help stabilize moisture levels as well as stimulate biological activity. The objectives of this study were to determine the effects of leachate recirculation and supplemental water addition on municipal solid waste decomposition and methane production in three anaerobic digestion reactors. Anaerobic digestion with leachate recirculation and supplemental water addition showed the highest performance in terms of cumulative methane production and the stabilization period time required. It produced an accumulated methane production of 54.87 l/kg dry weight of MSW at an average rate of 0.58 l/kg dry weight/d and reached the stabilization phase on day 180. The leachate recirculation reactor provided 17.04 l/kg dry weight at a rate of 0.14l/kg dry weight/d and reached the stabilization phase on day 290. The control reactor provided 9.02 l/kg dry weight at a rate of 0.10 l/kg dry weight/d, and reached the stabilization phase on day 270. Increasing the organic loading rate (OLR) after the waste had reached the stabilization phase made it possible to increase the methane content of the gas, the methane production rate, and the COD removal. Comparison of the reactors' efficiencies at maximum OLR (5 kgCOD/m(3)/d) in terms of the methane production rate showed that the reactor using leachate recirculation with supplemental water addition still gave the highest performance (1.56 l/kg dry weight/d), whereas the leachate recirculation reactor and the control reactor provided 0.69 l/kg dry weight/d and 0.43 l/kg dry weight/d, respectively. However, when considering methane composition (average 63.09%) and COD removal (average 90.60%), slight differences were found among these three reactors.     

IMPROVEMENT OF LEACHATE PREDICTION THROUGH MUNICIPAL SOLID WASTE LAYERS1

ABSTRACT: Existing leachate prediction models over- or underestimate leachate generation by up to three orders of magnitude. Practical experiments show that channeled flow in waste leads to rapid discharge of large leachate volumes and heterogeneous moisture distributions. In order to more accurately predict leachate generation, leachate models must be improved. To predict moisture movement through waste, the one-domain water balance model HELP, and two-domain PREFLO, are tested. Experimental waste and leachate flow values are compared with model predictions. When calibrated with experimental parameters, the HELP model yields reasonable predictions of cumulative leachate flow and PREFLO provides estimates of breakthrough time. In the short term, field capacity has to be reduced to 0.12 and effective storage and hydraulic conductivity of the waste must be increased to 0.2 and 2.2 cm/s respectively. In the long term, a new modeling approach must be developed to adequately describe the moisture movement mechanisms.     

Critical review for the quantification of leachate production: Evaluation example for the “Oum Azza” public landfill in Rabat city,Morocco

The estimation of leachate quantities produced in landfills is necessary to dimension the treatment plants allowing to reduce the polluting load of these effluents and consequently avoid their negative impacts on the environment. Different leachate quantification methods were used in this study to assess the leachate volume produced at the Oum Azza landfill. The water balance method give comparable estimations of leachate production to the Ouled Berjal landfill ratio. The first method showed average values between 487 and 495 m³/day for 2015, 2018, and 2019, and at the same time, the second method gave values between 470 and 477 m³/day for the same years. In contrast, the World Bank ratio showed high values that vary between 2260 and 2295 m³/day for 2015, 2018, and 2019. The on-site data and the statistical analysis showed us that the World Bank ratio is not adapted for the estimation of the leachates produced in Oum Azza landfill, while the water balance and the ratio of Ouled Berjal landfill allowed to give comparable results to reality.     

Chemical analysis of soil and leachate from experimental wetland mesocosms lined with coal combustion products

Small-scale (1 m2) wetland mesocosm experiments were conducted over two consecutive growing seasons to investigate the effects on soil and leachate chemistry of using a recycled coal combustion product as a liner. The coal combustion product used as a liner consisted of flue gas desulfurization (FGD) by-products and fly ash. This paper provides the chemical characteristics of mesocosm soil and leachate after 2 yr of experimentation. Arsenic, Ca, and pH were higher in FGD-lined mesocosm surface soil relative to unlined mesocosms. Aluminum was higher in the soils of unlined mesocosms relative to FGD-lined mesocosms. No significant difference of potentially phytotoxic B was observed between lined and unlined mesocosms in the soil. Higher pH, conductivity, and concentrations of Al, B, Ca, K, and S (SO4-S) were observed in leachate from lined mesocosms compared with unlined controls while Fe, Mg, and Mn were higher in leachate from unlined mesocosms. Concentrations of most elements analyzed in the leachate were below national primary and secondary drinking water standards after 2 yr of experimentation. Initially high pH and soluble salt concentrations measured in the leachate from the lined mesocosms may indicate the reason for early effects noted on the development of wetland vegetation in the mesocosms.     

Soil testing to predict phosphorus leaching

Subsurface pathways can play an important role in agricultural phosphorus (P) losses that can decrease surface water quality. This study evaluated agronomic and environmental soil tests for predicting P losses in water leaching from undisturbed soils. Intact soil columns were collected for five soil types that a wide range in soil test P. The columns were leached with deionized water, the leachate analyzed for dissolved reactive phosphorus (DRP), and the soils analyzed for water-soluble phosphorus (WSP), 0.01 M CaCl2 P (CaCl2-P), iron-strip phosphorus (FeO-P), and Mehlich-1 and Mehlich-3 extractable P, Al, and Fe. The Mehlich-3 P saturation ratio (M3-PSR) was calculated as the molar ratio of Mehlich-3 extractable P/[Al + Fe]. Leachate DRP was frequently above concentrations associated with eutrophication. For the relationship between DRP in leachate and all of the soil tests used, a change point was determined, below which leachate DRP increased slowly per unit increase in soil test P, and above which leachate DRP increased rapidly. Environmental soil tests (WSP, CaCl2-P, and FeO-P) were slightly better at predicting leachate DRP than agronomic soil tests (Mehlich-1 P, Mehlich-3 P, and the M3-PSR), although the M3-PSR was as good as the environmental soil tests if two outliers were omitted. Our results support the development of Mehlich-3 P and M3-PSR categories for profitable agriculture and environmental protection; however, to most accurately characterize the risk of P loss from soil to water by leaching, soil P testing must be fully integrated with other site properties and P management practices.     

煤矸石酸雨淋滤特征的研究

本文对重庆中梁山煤矸石在自然酸度和模拟酸雨下静态态及动态淋溶特征进行了研究。结果表明,淋出液成弱碱性,其中的铅、锌、铬、镍、铜和铁等元素的浓度均超过了水综合排放标准和地面水环境质量标准规定的阈值;在模拟酸雨中上述离子的溶出能力强于在于蒸溜水中;温度升高时各元素及总离子的淋出量增大。     

Fertilizer source effect on ground and surface water quality in drainage from turfgrass

Nutrients in surface and ground water can affect human and aquatic organisms that rely on water for consumption and habitat. A mass-balance field study was conducted over two years (July 2000-May 2001) to determine the effect of nutrient source on turfgrass runoff and leachate. Treatments were arranged in an incomplete randomized block design on a slope of 7 to 9% of Arkport sandy loam (coarseloamy, mixed, active, mesic Lamellic Hapludalf) and seeded with Kentucky bluegrass (Poa pratensis L.) and perennial ryegrass (Lolium perenne L.). Three natural organic (dairy and swine compost and a biosolid) and two synthetic organic nutrient sources (readily available urea and controlled-release N source sulfur-coated urea) were applied at rates of 50 and 100 kg N ha(-1) per application (200 kg ha(-1) yr(-1)). Runoff water collected from 33 storms and composite monthly leachate samples collected with ion exchange resins were analyzed for nitrate (NO3- -N), phosphate (PO4(3-) -P), and ammonium (NH4+ -N). Nutrient concentrations and losses in both runoff and leachate were highest for the 20-wk period following turfgrass seeding. The NO3- -N and NH4+ -N losses declined significantly once turfgrass cover was established, but PO4(3-) -P levels increased in Year 2. Turf's ability to reduce nutrient runoff and leachate was related to overall plant growth and shoot density. The use of natural organics resulted in greater P loss on a percent applied P basis, while the more soluble synthetic organics resulted in greater N loss.