Keywords: COD removal, chemical oxygen demand, landfill, leachate, microsilica, optimisation, value–added material, municipal solid waste, MSW, clay liner systems, adsorption capacity, waste management, adsorbent
Assessment of microsilica as a value–added material for municipal solid waste clay liner system
This study was carried out to provide landfill clay liner soil along with admixture microsilica in different proportions. The physico–chemical characteristics were carried out to characterise the selected liners. The optimum conditions vis., time of adsorption, adsorbent dosage and pH were studied for the liners. The optimum pH values for COD removals are determined for clay soil, mix 1 : 20, mix 1 : 10 composites as 5, 6 and 6 and optimum contact times are 45, 60 and 60 minutes, respectively. The correlation coefficients of isotherm analysis reveals that Freundlich isotherm for clay soil, mix 1 : 20 and mix 1 : 10 composites (0.90, 0.88 and 0.78) shows better fit as compared with Langmuir isotherm. The adsorption capacities in terms of COD reduction by two soil liners revealed that the microsilica addition has not altered the characteristics of clay soil. Hence, microsilica can be used as municipal solid waste leachate since it is an abundant and large quantity available waste material to use as adsorbent.