A kinetic study on anaerobic reduction of sulphate, Part I: Effect of sulphate concentration

The kinetics of anaerobic reduction of sulphate was studied in continuous bioreactors. The effects of initial sulphate concentration and its volumetric loading on the kinetics of reaction and activity of sulphate-reducing bacteria were investigated. The increase in initial concentration of sulphate in the range 1.0– 10.0 kg m −3 enhanced the reaction rate from 0.007– 0.17 kg m −3 h −1 . For a given initial sulphate concentration increasing the volumetric loading rate of sulphate led to a linear increase in volumetric reduction rate. The initial concentration of sulphate did not have a significant effect on maximum specific growth rate ( μ m ), decay coefficient ( k d ) on bacterial yields ( Y x/sulphate and Y x/acetate ), with the values of these coefficients being 0.061, 0.035 h −1, 0.567 g bacteria/g sulphate and 0.572 g bacteria/g acetate, respectively. The saturation constant ( K s ) was an increasing linear function of initial sulphate concentration, with the lowest and highest values being 0.027 and 0.125 kg m −3 , respectively. Using the experimental data a kinetic model, incorporating terms for the effects of initial and residual concentrations of sulphate and biomass, was developed.