A KINETIC STUDY ON ANAEROBIC SULPHATE REDUCTION - THE EFFECT OF TEMPERATURE

摘要

Kinetics of anaerobic reduction of sulphate was studied in a continuous bioreactor. The effects of temperature and volumetric loading of sulphate were investigated. Acetate was used as an electron donor. For the whole range of applied temperatures, 20 to 35 °C, the increasing of volumetric loading rate up to 0.08 to 0.1 kg m~(-3) h~(-1) resulted in a linear increase in reduction rate. Beyond this level the reduction rate became independent of volumetric loading. Despite the similar trends with volumetric loading, the reduction rate was influenced by temperature, with a maximum rate of 0.075 kgm~(-3)h~(-1) observed at 35 °C. The effect of temperature on maximum specific growth rate (μ_(max)) and bacterial yield was insignificant. The values of maximum specific growth rate and yield were 0.06 h~(-1) and 0.56-0.60 kg bacteria (kg sulphate)~(-1) respectively. Saturation constant (K_s) and decay coefficient (K_d) were both temperature dependent. The increase of temperature while decreasing the value of K_s, resulted in higher values for K_d. Using the experimental data a kinetic model incorporating terms for sulphate and bacterial concentrations, as well as temperature was developed for anaerobic reduction of sulphate.