Predicting hydraulic conductivity landfill soil liner with nomograph

In the landfill, lining systems play an essential function in providing a barrier between the waste and the environment. Soil liners are used in the soil liner system to reduce leachate infiltration and prevent ground pollution. It is essential to compact the layer properly to achieve low hydraulic conductivity of 1x 10-9 m/s. The purpose of this study is to develop a nomograph in predicting hydraulic conductivity without or with minimal laboratory test in designing a modified soil liner. Geopolymer consists of palm oil boiler ash as source material and sodium hydroxide mixed with sodium silicate as an alkaline solution. Laboratory work involved physical properties tests, compaction characteristics, and hydraulic conductivity of modified mixtures. The percentage of geopolymer in the mix varies between 0%, 10%, 15%, and 20% of the dry weight of lateritic soil. The conclusion was reached based on compaction characteristics; compacted geopolymers are compatible with lateritic soils. Hydraulic conductivity of the soils was reduced by less than 1×10-9 m/s and found that laterite with a 15% of geopolymer mixture is optimum to be used as a modified soil liner in a landfill. The nomograph in predicting hydraulic conductivity, k, were developed as alternative guidelines for engineers to design landfill soil liners without conducting laboratory testing that takes a long time and can reduce the cost and time.