Department of Civil Engineering, 2 Eylul Campus, Anadolu University, Eskisehir 26480, Turkey.
Waste Manag. 2014 Jan;34(1):112-24. doi: 10.1016/j.wasman.2013.10.008. Epub 2013 Nov 9.
Landfill bottom liners are generally constructed with natural clay soils due to their high strength and low hydraulic conductivity characteristics. However, in recent years it is increasingly difficult to find locally available clay soils that satisfy the required engineering properties. Fine grained soils such as sepiolite and zeolite may be used as alternative materials in the constructions of landfill bottom liners. A study was conducted to investigate the feasibility of using natural clay rich in kaolinite, sepiolite, zeolite, and their mixtures as a bottom liner material. Unconfined compression tests, swell tests, hydraulic conductivity tests, batch and column adsorption tests were performed on each type of soil and sepiolite-zeolite mixtures. The results of the current study indicate that sepiolite is the dominant material that affects both the geomechanical and geoenvironmental properties of these alternative liners. An increase in sepiolite content in the sepiolite-zeolite mixtures increased the strength, swelling potential and metal adsorption capacities of the soil mixtures. Moreover, hydraulic conductivity of the mixtures decreased significantly with the addition of sepiolite. The utilization of sepiolite-zeolite materials as a bottom liner material allowed for thinner liners with some reduction in construction costs compared to use of a kaolinite-rich clay.
垃圾填埋场的底部衬垫通常由天然粘土构成，因为它们具有高强度和低水力传导率的特性。然而，近年来，越来越难以找到满足所需工程特性的本地可用粘土。海泡石和沸石等细粒土壤可用作垃圾填埋场底部衬垫的替代材料。进行了一项研究，以调查富含高岭石、海泡石、沸石及其混合物的天然粘土作为底部衬垫材料的可行性。对每种土壤和海泡石-沸石混合物进行了无侧限抗压强度试验、膨胀试验、水力传导率试验、批量和柱吸附试验。目前的研究结果表明，海泡石是影响这些替代衬垫的地质力学和地质环境特性的主要物质。海泡石-沸石混合物中海泡石含量的增加会增加土壤混合物的强度、膨胀潜力和金属吸附能力。此外，随着海泡石的加入，混合物的水力传导率显著降低。与使用富高岭石的粘土相比，海泡石-沸石材料作为底部衬垫材料的使用可以使衬垫更薄，从而降低一些建设成本。
