A multi#x2010;stage biological process is described for treating effluents containing high levels of calcium sulphate, soluble organic matter and. heavy metals. Sulphate is reduced anaerobically to sulphide which is used to precipitate heavy metals, while the remaining H2S is stripped off. Residual soluble organic matter from the first stage is removed aerobically in a second stage. Effluent saturated with respect to calcium sulphate required 3 g molassesl#x2010;1effluent to convert 90 of the influent sulphate to sulphide.
展开▼
