Oxidative biological removal of sulphide from waste water - using short-fall in oxygen, giving conversion largely to sulphur

摘要

In oxidative biological purification of waste water, by converting sulphide to S and sulphate by means of S-oxidising bacteria in presence of 02, the amt. of 02 used is less than that needed for complete oxidn. of sulphide to sulphate. Pref. the amt. of 02 used is 0.5-1.5 mols w.r.t. 1 mol of sulphide, and 02 consumption is controlled by regulating the 02 concn. in dependence on the sulphide concn. The hydraulic residence time is less than 20 mins. The reactor may contain support material, this may be a polyurethane foam, to immobilise th biomass.