Estimation of effect of sugarcane bagasse biochar amendment in landfill soil cover on geotechnical properties and landfill gas emission

Abstract

In a sanitary landfill, the final cover plays an important role in reducing the landfill gas emission to the atmosphere and in preventing the ingress of rainwater into the dumped waste. The present study investigated the suitability of sugarcane bagasse biochar as an amendment to the cover soil to improve the required landfill liner properties. The amended cover soil sugarcane bagasse (SSB) was tested for its stability and effectiveness, in terms of both geotechnical properties and methane mitigation efficiency. The effects of amending 15%, 20%, and 25% of sugarcane bagasse biochar (passing through 300 micron Indian Standard sieve) on the geotechnical properties of the SSB indicated that the SSB with 25% biochar showed the required values as per the standard with maximum dry density of 1.57�grams per cubic centimeter (g/cm3), liquid limit, plasticity index, and percentage of fines 48.5%, 16.3%, and 74.7%, respectively, and permeability of 0.9�נ10?7. A column study that was conducted to determine the methane emission from the cover soil showed a 65.8% reduction in the methane emission compared to that of a column without SSB cover, with a cumulative methane emission of 410�milliliters (mL) at the end of 200�hours (h). On the other hand, the volume of methane emitted after 310�h from the column without cover and with the SSB cover was 1850�mL and 692�mL, respectively. The difference between these two values is found to be 22% of the total methane that the cover would have handled in its lifetime (5267�mL). Thus, there is an increase in the percentage of methane adsorption by soil cover from 15% to 22% when the soil was amended with 25% sugarcane bagasse biochar. � 2018 Wiley Periodicals, Inc.