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 down flow 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).
