Geotechnical analysis of two Nigerian soils for use as clay liners

The cretaceous Auchi shale and the Tertiary Imo shale in SW Nigeria were investigated for their suitability for use as a clay seal in waste disposal landfills. Geotechnical analyses indicated they are highly plastic inorganic clays. Although their geotechnical and chemical properties were within the range suggested by various authors for use as mineral seals, care would need to be taken with the Okada shales as they contain smectite and would be difficult to work and liable to cracking.      

Mechanisms of Leakage through Synthetic Landfill Liner Materials

The introduction of synthetic lining materials for leachate containment and the prevention of groundwater contamination was an important development in landfill technology. These materials have a low hydraulic conductivity which results in minimal leachate release by bulk fluid flow (advection) provided that the barrier (and its construction) is free from defects. However, the effectiveness of these materials as barriers cannot be confirmed unless contaminant release by diffusion is also taken into consideration.
This paper reviews the mechanisms by which transport through barriers occur. It highlights the role of diffusion as a pathway for organic compounds to migrate through synthetic liners and indicates its importance in terms of environmental impact and landfill design.     

《钠基膨润土防水毯》行标的制定

介绍了《钠基膨润土防水毯》标准制定的背景和制定的依据，并对标准中的产品分类、试验项目、实验方法、性能指标等做了详细的阐述。     

污水厂污泥制备垃圾填埋场防渗衬层材料研究

以城市污水厂的污泥复合高岭土用作垃圾填埋场防渗衬层材料，研究了千污泥的掺入量及其颗粒大小、复合土密度、渗滤液性质对污泥复合土渗透性能的影响。结果表明，复合土中污泥的最佳质量分数为40％；提高复合土的干密度可显著降低其渗透系数，当干密度为1.08g／cm^3时复合土的渗透系数达10^-7cm／s数量级，符合垃圾填埋场防渗衬层的要求；渗滤液性质对渗透性能的影响较大，当其电解质浓度较大时复合土的渗透性能随之提高。此外，考察了污泥复合土对重金属的吸附效果，结果表明该复合土可有效吸附垃圾渗滤液中的Cu^2＋、Zn^2＋等重金属。     

填埋场边坡土工衬垫结构的稳定性分析方法

本文针对现代卫生填埋场典型的防渗衬垫结构,分析了边坡衬垫破坏的原因和形式,结合计算分析了常用土工材料对边坡稳定的影响,并对不同条件下土工材料的选用以及工程设计中的一些注意事项提出了建议。     

膨润土防水毯对回填土密实度的要求

阐述了膨润土防水毯施工中回填土密实度的重要性,介绍了土壤重型击实密度的概念、测试方法和膨润土防水毯对回填土密实度的要求,并提出了回填土的施工要求和技术指导。     

钻探工程用粘土矿物材料应用综述

钻探工程是粘土矿物材料的重要应用领域,涉及的粘土矿物品种有蒙脱石、坡缕石、海泡石、高岭石、累托石、水云母、绿泥石等,其中以蒙脱石为主要成分的膨润土用量最大。钻探工程用粘土矿物材料分为水性造浆材料、油性造浆材料、防水堵漏材料、配浆评价土等,其中水性造浆材料占总用量的90%,油性造浆材料在深井、复杂地层钻探工程中应用前景广阔,防水堵漏材料和配浆评价土是粘土矿物材料中的高端产品,防水堵漏材料的复配技术对钻探工程实施有更好的实际价值。     

膨润土防水毯在中海油大厦地下车库防水工程中的应用

介绍了钠基膨润土防水毯在中海油大厦（上海）地下车库防水工程中的应用,包括所选用的Vohex DS钠基膨润土防水毯的主要性能特点和在地下结构中的施工工艺及部分特殊部位如管道穿透部位、预留甩头、侧墙收口的处理方法。     

膨润土土工合成材料的研究

将所合成的相对分子质量约为3~4万的聚丙烯酰胺(PAM)与甲醛反应使之羟甲基化,然后将羟甲基化聚丙烯酰胺和单体丙烯酰胺(AM)脱水缩合,得到产物改性聚丙烯酰胺.适宜的反应物摩尔比n(PAM)∶n(甲醛)∶n(AM)=1∶0.6∶0.6,羟甲基化转化率可达99%以上,丙烯酰胺转化率可达93%以上.改性聚丙烯酰胺以过硫酸铵为引发剂,N,N′-亚甲基双丙烯酰胺为交联剂在室温下发生交联反应.其优点是交联速度快、聚合放热温度低、在侧链发生交联反应、抗水解能力强,吸水膨胀倍数与膨润土相当.将改性聚丙烯酰胺与膨润土混合(其中膨润土质量约占70%)制成的膨润土土工合成材料,其体积膨胀率为190%,基本达到我国建筑行业标准实用要求.该产品经久耐用,为土工合成材料的制备技术探索了一条新路.     

膨润土防水毯在基础底板防水工程中的应用

膨润土防水毯可广泛应用于市政、公路、水利及民用建筑中,通过首都机场三号航站楼滑行桥下基础底板防水工程,详细介绍了膨润土防水毯的施工工艺,尤其对各特殊节点部位施工进行了详述,保证了工程质量。     

Effect of biopolymers on permeability of sand-bentonite mixtures

Application of biopolymer-modified geomaterials in waste disposal practices is gaining wide acceptance due to their superior tensile characteristics and improved crack resistance. Permeability is an important design parameter which determines the suitability of a material as a liner for construction of engineered landfills. Given this, the permeability characteristics of sand-bentonite mixtures amended with biopolymers was studied using a modified-falling head permeability apparatus under an accelerated gravity environment. Both distilled water and synthetic leachate were utilized as permeant liquid to assess the role of biopolymer amendment on the permeation behavior of sand-bentonite mixtures. Experimental results indicate that addition of biopolymers causes aggregation of the clay platelets, which in turn enhances the permeation behavior of the biopolymer-modified sand-bentonite mixtures. These mixtures meet the regulatory requirement of the liner.     

Landfill Lining for Leachate Containment

There is an increasing need for engineered liners to prevent the escape of leachate and to control the migration of landfill gas. This has been influenced by new European and UK legislation and codes of practice.
General principles of site design are explained, followed by a review of the advantages and disadvantages of different liner systems, including mineral liners (natural clay, mudrocks and soil/bentonite admixtures), geomembranes and composite liners.
The need for conservative factors of safety in site design and high standards of quality control, involving full-time supervision and independent certification of the installation works, are considered essential to ensure the effectiveness of the barrier.
There is no one ideal liner material. Composite mineral/geomembrane liners provide the highest degree of security against leakage and, as such, should be considered as 'the norm'rather than for use only in particularly high-risk situations.     

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/...     

某垃圾填埋场坝基渗透性分析及防治措施

由拟建东港市赤榆垃圾卫生填埋场工程出发,结合该工程建设场地的地质背景条件,通过物探、钻探、压水试验等方法分析了坝基部位的渗透性影响因素,并提出坝基防治措施建议。     

垃圾填埋场渗滤液处理的机理和方法的探讨

近几年来,随着工农业生产的巨大发展和人口的急剧膨胀,垃圾的产生量越来越多.我国垃圾平均增长率达9%以上,超过世界平均增长率（8.42%）.因此垃圾处理是个亟待解决的问题.目前处理城市垃圾固体废弃物的常用方法是填埋法,而垃圾的堆放对周围的环境造成了影响,尤其是对水环境影响更大.很多堆放场产生的垃圾渗滤液严重地污染了地下水质.作者从微生物的角度、土水势的角度和水在多孔介质中渗流的角度,提出了处理垃圾填埋场渗滤液的方法.     

Treatment of landfill leachate by the Fenton process

In recent years, studies of leachate treatment by conventional Fenton, photo-Fenton and electro-Fenton processes have indicated that these methods can effectively reduce concentrations of organic contaminants and color. In addition, the process can increase the biodegradable fraction of organic constituents in leachate, particularly in mature or biologically recalcitrant leachate. Oxidation and coagulation both play important roles in the removal of organics. Initial pH, dosages of Fenton reagents, aeration, final pH, reagent addition mode, temperature, and UV irradiation may influence final treatment efficiency. In this paper, current knowledge of performance and economics of Fenton processes for treatment of landfill leachate as reported for laboratory, pilot and full-scale studies is reviewed, with the conclusion that the Fenton process is an important and competitive technology for the treatment or pretreatment of landfill leachate.     

武汉市金口垃圾场渗滤液水质特征、和UASB处理系统

渗滤液中含有多种对环境有害的污染物质,垃圾渗滤液的性质与垃圾成分、垃圾含水率、降水量、汽温和填埋时间等因素有关,其浓度和性质随时间呈高度的动态变化关系。根据现场运行经验,只有在满足进水化学耗氧量(COD)浓度大于5000mg/L、氨氮浓度小于600mg/L、进水温度大于30℃的条件下,上流式厌氧污泥床(UASB)系统才能取得比较理想的处理效果。     

Transformation of metals speciation in a combined landfill leachate treatment

Landfill leachate was treated by a combined sequential batch reactor (SBR), coagulation, Fenton oxidation and biological aerated filter (BAF) technology. The metals in treatment process were fractionated into three fractions: particulate and colloidal (size charge filtration), free ion/labile (cation exchange) and non-labile fractions. Fifty percent to 66% Cu, Ni, Zn, Mn, Pb and Cd were present as particulate/colloidal matter in raw leachate, whereas Cr was present 94.9% as non-labile complexes. The free ion/labile fractions of Ni, Zn, Mg, Mn, Pb and Cd increased significantly after treatment except Cr. Fifty-nine percent to 100% of Al was present mainly as particulate/colloidal matter > 0.45 μm and the remaining portions were predicted as non-labile complexes except in coagulation effluent. The speciation of Fe varied significantly in various individual processes. Visual MINTEQ simulation showed that 95-100% colloidal species for Cu, Cd and Pb were present as metal-humic complexes even with the lower dissolved organic carbon. Optimum agreements for the free ion/labile species were within acidic solution, whereas under-estimated in alkaline effluents. Overestimated particulate/colloidal fraction consisted with the hypothesis that a portion of colloids in fraction < 0.45 μm were considered as dissolved.     

防渗墙粘土混凝土配合比试验研究

粘土混凝土性能介于塑性混凝土和刚性混凝土之间,具有和易性好、早期强度低、后期强度增长快、抗渗性能好、低弹模和相对较高的强度等特点,是一种理想的防渗墙材料。本文结合山西省米家寨水库除险加固工程粘土混凝土防渗墙试验研究工作,对粘土混凝土原材料选用、配合比设计及其抗渗性能进行研究。     

Inhibition and recovery in a fixed microbial film leachate treatment system subject to shock loading of copper and zinc

The impacts of shock loadings of copper and zinc (up to 50 mg l(-1)) on the treatment efficiency of a mesoscale-fixed microbial film landfill leachate treatment system were investigated. Treatment inhibition and recovery were monitored in sequence over two 36 h experimental runs. The fate of added metals was also investigated. Copper, and to a lesser extent zinc, added to the treatment systems accumulated on the biofilm media. Increasing copper inputs (>10 mg l(-1)) progressively inhibited biological treatment of ammoniacal-nitrogen and carbon; this inhibition persisted into the recovery phase for nitrogen but not for carbon. Only the highest input of zinc affected media metal contents and carbon treatment rates; the latter inhibitory effect did not persist into the recovery phase. A small proportion of the metals accumulated on the biofilm media during the inhibition phase was released into the bulk leachate during the recovery experiment. These findings suggest a need to manage metal inputs into leachate treatment systems in order to ensure their continued efficacy.