苏州七子山垃圾填埋场渗沥液设计水质的估算

在对垃圾填埋场渗沥液污染物的转化、溶出规律分析的基础上，建立了污染物溶出模式和污染物负荷计算模式，并结合苏州七子山垃圾填埋场的实际情况，确定了其渗沥液在不同条件下的水质。研究表明，在填埋场填埋稳定期的枯水期和丰水期的ＣＯＤｃｒ和ＢＯＤ５浓度分别为２７．２４～４０．８６ｍｇ／ｌ、１３．１７～１９．７５ｍｇ／ｌ和１３．４６～２０．２１ｍｇ／ｌ、６．５１～９．７７ｇ／ｌ；在填埋场封场后枯水期和丰水期的ＣＯＤｃｒ和ＢＯＤ５分别为４．８８～７．３３ｇ／１、２．３６～３．５４ｇ／ｌ和２．２２～３．３４ｇ／ｌ、１．０８～１．６１７ｇ／ｌ。     

铬渣中Cr^6＋的溶出特性研究

研究了铬渣中C_r~(6+)的溶出特性。研究表明,铬渣遇水会溶出碱性物质和C_r~(6+)。反复浸出时,其累积溶出负荷持续上升。这表明在碱性条件下,C_r~(3+)易被氧化为C_r~(6+)而溶出。在淋溶初期,其溶出量很高;随后,迅速降低;当C_r~(6+)浓度达到100mg/l以后,下降缓慢。研究得到,C_r~(6+)累积溶出负荷,与流出液体积呈显著对数相关。     

Fenton氧化法深度处理垃圾渗滤液的试验研究

采用Fenton氧化法对经生化处理后的垃圾渗滤液进行深度处理。结果表明,Fenton反应最佳工艺条件:初始pH值为3,H2O2加入量为3.0mL/L,FeSO4.7H2O加入量为3.5g/L,反应时间120min。生化处理后的垃圾渗滤液经Fenton氧化法深度处理后,CODCr由处理前的300mg/L,降至处理后的93mg/L,去除率达69.0%,出水水质达到新修订的《生活垃圾填埋场污染控制标准》(GB16889-2008)排放标准。     

渗滤液循环回灌出水在混凝处理中的去除特性

经循环回灌后的渗滤液出水含有大量的腐殖质,其生物降解性差、氨氮含量高,具有类似长填龄填埋层渗滤液的水质特征。用混凝法处理渗滤液循环回灌出水,通过混凝pH、混凝剂种类及其投加量实验,确定了最佳混凝条件;并通过分析混凝处理前后渗滤液循环回灌出水的分子量变化和从出水中分离出的腐殖酸(HA)、富里酸(FA)和Hydrophilic(HyI)三种组分的变化,讨论了混凝法对渗滤液循环回灌出水去除效率不高的原因。研究表明,聚合硫酸铁(PFS)在pH=5、投药量为0.22g/L(以Fe2O3计)的条件下的混凝效果最佳,其对渗滤液循环回灌出水的COD去除率达58.1%。混凝剂对渗滤液循环回灌出水中的HA、FA和HyI组分的去除效果依次为:HA>FA>HyI。     

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.     

固体废弃物填埋场中土工膜衬垫系统的发展与应用

固体废弃物填埋场中产生的渗滤液污染土壤和地下水 ,在填埋场正确设置防渗的衬垫系统是非常重要的。本文对国外土工膜衬垫系统在填埋场中的发展应用进行介绍和评价 ,分析了土工膜的选用原则 ,有助于我国合理和有效的进行土工膜衬垫的设置     

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     

Greenhouse gas emissions from landfill leachate treatment plants: A comparison of young and aged landfill

With limited assessment, leachate treatment of a specified landfill is considered to be a significant source of greenhouse gas (GHG) emissions. In our study, the cumulative GHG emitted from the storage ponds and process configurations that manage fresh or aged landfill leachate were investigated. Our results showed that strong CH₄ emissions were observed from the fresh leachate storage pond, with the fluxes values (2219–26,489 mg C m^?2 h^?1) extremely higher than those of N₂O (0.028–0.41 mg N m^?2 h^?1). In contrast, the emission values for both CH₄ and N₂O were low for the aged leachate tank. N₂O emissions became dominant once the leachate entered the treatment plants of both systems, accounting for 8–12% of the removal of N-species gases. Per capita, the N₂O emission based on both leachate treatment systems was estimated to be 7.99 g N₂O–N capita^?1 yr^?1. An increase of 80% in N₂O emissions was observed when the bioreactor pH decreased by approximately 1 pH unit. The vast majority of carbon was removed in the form of CO₂, with a small portion as CH₄ (<0.3%) during both treatment processes. The cumulative GHG emissions for fresh leachate storage ponds, fresh leachate treatment system and aged leachate treatment system were 19.10, 10.62 and 3.63 Gg CO₂ eq yr^?1, respectively, for a total that could be transformed to 9.09 kg CO₂ eq capita^?1 yr^?1.     

Recovery of volatile fatty acids via membrane contactor using flat membranes: Experimental and theoretical analysis

Volatile fatty acid (VFA) separation from synthetic VFA solutions and leachate was investigated via the use of a membrane contactor. NaOH was used as a stripping solution to provide constant concentration gradient of VFAs in both sides of a membrane. Mass flux (12.23 g/m² h) and selectivity (1.599) observed for acetic acid were significantly higher than those reported in the literature and were observed at feed pH of 3.0, flow rate of 31.5 ± 0.9 mL/min, and stripping solution concentration of 1.0 N. This study revealed that the flow rate, stripping solution strength, and feed pH affect the mass transfer of VFAs through the PTFE membrane. Acetic and propionic acid separation performances observed in the present study provided a cost effective and environmental alternative due to elimination of the use of extractants.     

膜法处理垃圾渗滤液新技术实验研究

将改进间歇式活性污泥法与FIL-MAX膜组合处理工艺相结合,应用于沈阳某垃圾场垃圾渗滤液处理工程实例中。通过实验,分析了COD、NH3-N等指标的处理效率以及影响因素,最终得出改进间歇式活性污泥法与FIL-MAX组合工艺处理在一定程度上改善膜污染、膜堵塞等常见问题。