Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
Environ Sci Pollut Res Int. 2021 Jun;28(24):30975-30985. doi: 10.1007/s11356-021-12863-4. Epub 2021 Feb 16.
For safe disposal of wastes in landfills, compacted bentonite is recommended as bottom liners due to their significant cation exchange (CEC) and swelling capacity, low permeability and large specific surface area (SSA). The present investigation carried out various experimental studies determining the compressibility behaviour and unconfined compressive strength (UCS) of two different compacted bentonites in the presence of municipal solid waste (MSW) and synthetic MSW leachates. Various examinations were conducted determining alterations in consolidation parameters like the coefficient of consolidation (c), time taken for 90% consolidation (t) and compression index (C) with both leachates. The outcomes reveal that C and t values of both bentonites declined; however, c value rose. Results also indicated that under any given consolidation pressure, a lesser void ratio was achieved for leachates. UCS of both bentonites reduced with leachates' interaction yet, lying within the recommended a value higher than 200 kPa. A comparative assessment of the two bentonites displayed that bentonite having higher CEC and swelling capacity, and SSA unveiled more excellent C and t values and a reduction in the UCS. A higher variation in behaviour of bentonites was perceived in the existence of MSW leachate in comparison to synthetic MSW leachate.
为了安全处理垃圾填埋场中的废物,建议使用压实膨润土作为底层衬垫,因为它们具有显著的阳离子交换(CEC)和膨胀能力、低渗透性和大比表面积(SSA)。本研究进行了各种实验研究,确定了两种不同压实膨润土在存在城市固体废物(MSW)和合成 MSW 浸出液时的压缩性行为和无侧限抗压强度(UCS)。各种检查确定了固结参数的变化,如固结系数(c)、90%固结所需的时间(t)和压缩指数(C),两者都受到浸出液的影响。结果表明,两种膨润土的 C 和 t 值都降低了,而 c 值却升高了。结果还表明,在任何给定的固结压力下,浸出液的空隙比更小。两种膨润土的 UCS 都随着浸出液的相互作用而降低,但仍在推荐值 200 kPa 以上。对两种膨润土的比较评估表明,CEC 和膨胀能力较高的膨润土以及 SSA 具有更优异的 C 和 t 值,UCS 降低。与合成 MSW 浸出液相比,在存在 MSW 浸出液的情况下,膨润土的行为变化更高。