Determination of Schulze equation for chemical oxygen demand reduction using stabilized landfill refuse media

Three columns each with 770 cm2 of surface area and 60-105 cm effective depth were set up for this study. These columns were filled with compacted, stabilized refuse. High-strength brewery wastewaters were uniformly trickled down the medium. Overall, 16 runs with various organic loadings were tested and the results demonstrated that the stabilized refuse had excellent capability in removing chemical oxygen demand (COD). The COD removal efficiency reached 95% at a depth of 60 cm at Q = 8 L/day for the initial COD of approximately 6000 mg/L and the efficiency increased to >99% at a depth of 90 cm (organic loading of 0.69 kg/m3/day). As would be expected, the filter performance is a function of flow rate, influent COD concentration, and bed depth. The Schulze equation is able to predict the COD removal performance well. The variations of pH, oxidation reduction potential, and volatile fatty acids indicated that the acidogenesis reaction occurred in the upper layers.