Evaluating the Effect of pH, Temperature, and Hydraulic Retention Time on Biological Sulphate Reduction Using Response Surface Methodology

Abstract

Biological sulphate reduction (BSR) has been identified as a promising alternative for treating acid mine drainage. In this study, the effect of pH, temperature, and hydraulic retention time (HRT) on BSR was investigated. The Box–Behnken design was used to matrix independent variables, namely pH (4–6), temperature (10–30 °C), and HRT (2–7 days) with the sulphate reduction efficiency and sulphate reduction rate as response variables. Experiments were conducted in packed bed reactors operating in a downflow mode. Response surface methodology was used to statistically analyse the data and to develop statistical models that can be used to fully understand the individual effects and the interactions between the independent variables. The analysis of variance results showed that the data fitted the quadratic models well as confirmed by a non-significant lack of fit. The temperature and HRT effect were significant (p < 0.0001), and these two variables had a strong interaction. However, the influence of pH was insignificant (p > 0.05).

Water Quality Engineering and Wastewater Treatment

“…The papers in the Special Issue are summarized as follows: Biological sulfate reduction (BSR) has been recognized as a favorable option for the purification of acid mine drainage. The influence of temperature, pH, and hydraulic retention time (HRT) on BSR has been examined in downflow mode packed bed reactors [1]. They concluded that HRT and temperature had a powerful interaction; however, the effect of pH was negligible.…”