N Moghadam - School of Chemical Engineering, College of Engineering, Tarbiat Modares University, P.O.Box ۱۴۱۱۵-۱۴۳, Tehran, Iran
M Nosrati - School of Chemical Engineering, College of Engineering, Tarbiat Modares University, P.O.Box ۱۴۱۱۵-۱۴۳, Tehran, Iran
S.A Shojaosadati - School of Chemical Engineering, College of Engineering, Tarbiat Modares University, P.O.Box ۱۴۱۱۵-۱۴۳, Tehran, Iran

Biological aerobic treatment of landfill leachate under thermophilic conditions is a way to reduce the pollutant contents of this concentrated wastewater. In this study, the treatability of landfill leachate using mesophilic and thermophilic activated sludge in the terms of Total Solids (TS), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), and Chemical Oxygen Demand (COD); was investigated by means of a continuous aerobic mixed activated sludge tubular bioreactor. The period of treatment was 15 days at 40ºC and 20 days at 55ºC. These operations resulted in 44%, 33%, and 32% COD reductions at organic loading rates of 10.14, 16.9, and 32.96 kg/(m3.d) respectively, under mesophilic conditions (40ºC), and COD reductions of 54%, 49%, 44%, and 43% at organic loading rates of 5, 10.1, 17.37, and 32.96 respectively, under thermophilic conditions (55ºC). The values of kinetic parameters of Yield (YT), Decay rate constant (Kd), Maximum specific growth rate constant[Formula], and Monod equation rate constant (Ks) were found to be 0.31 kgMLSS/kgCOD, 0.38 d-1, 3.11 d-1, and 1311 mgCOD/l respectively, under mesophilic conditions (40ºC), and 0.24 kgMLSS/kgCOD, 0.60 d-1, 6.51 d-1, and 1210 mgCOD/l respectively, under thermophilic conditions (55ºC).

Landfill Leachate, Thermophilic, Mesophilic, Activated Sludge