Up-flow anaerobic sludge blanket (UASB) reactor to treat landfill leachate under tropical condition

Abstract

With the growth of population and changing the lifestyle, solid waste generation and management has become the major problem all over the world. Open dumping of solid waste has created problems related in health and the living standards of the people. Leachate generated from open dumping has created problems such as, surface and ground water pollution and soil contamination with toxic compounds. This study was conducted to investigate the applicability of Up-flow Anaerobic Sludge Blanket (UASB) reactor to leachate treatment under the ambient temperature condition. Treatment efficiencies were measured in terms of COD reduction percentage of leachate that fed to the UASB reactor. The reactor was operated 94 days at different Hydraulic Retention Times (HRT) with the objective of finding the optimum HRT value. Maximum COD removal efficiency of (64 ± 1) % was achieved when HRT was at 6 hours. Reactor inside pH was controlled within the range of 6.2 – 7.5. Gas production rate, composition and Oxygen Reduction Potential (ORP) were measured for all the HRT values to maintain the reactor in proper anaerobic condition. Methane composition in biogas produced was high for all HRT values and at 6 hours HRT it was (86.11±1.1) %. Maximum TSS removal efficiency of 66% was also achieved at 6 hours of HRT. But maximum VSS removal efficiency of 29% was achieved at 7 hours of HRT. When comparing the heavy metal removal, the highest removal efficiencies were achieved for Pb and Cr which are (55 ± 1)% and (47 ± 1) % respectively.