Kinetics evaluation of a pilot scale anaerobic biofilm digester treating leachate from a municipal solid waste transfer station

In this study, leachate from municipal solid waste (MSW) transfer station was treated in a pilot scale anaerobic biofilm digester (ABD) system under 30, 25, 20 and 10-day HRT. The maximum COD concentration entering the reactor was 46,944 mg/L and the reactor was under full operation for 163 days. The results showed that COD removal efficiency was above 95 % throughout the operation and measurement of the average daily biogas production yielded a value of 25 +/- 1 m3/day with a composition of 57 +/- 12 % methane and 26 +/- 6 % carbon dioxide. In comparison to the Monod and modified Stover-Kincannon (MSK) models, the second-order Grau model presented the best fit as a substrate-removal kinetic model for this ABD system with its R2, 0.999; while the MSK model for gas generation was proven to be a better fit than the Van der Meer and Heertjes model in predicting the amount of biogas and methane gas produced from leachate treatment via a pilot scale ABD.