Low temperature effects on anaerobic microbial kinetic parameters

Anaerobic sequencing batch reactors (ASBRs) were operated in the temperature range of 5 to 25 degrees C and 24, 16, 12, 8, 6 hour hydraulic retention times (HRTs) over a period of two years to evaluate the effects of different temperatures on the microbial kinetic parameters K, K-s, K-d, Y-g and mu(m). The values of K, K-d and mu(m) were found to decrease, and the half saturation constant, K, was found to increase with a decrease in temperature in accordance with the Arrhenius equation. Temperature coefficient, a values for substrate utilization rate, maximum specific growth rate, decay rate and half saturation constant were 1.083, 1.062, 1.076 and 1.05 respectively. Through the determination of kinetic parameters, a design engineer may be able to predict the performance of ASBR treatment systems over a wide range of low temperatures.