KONTROLL AV SULFID-TOXICITET VID ANAEROB RENING AV INDUSTRIELLA PROCESSVATTEN / Control of Sulphide Toxicity in Anaerobic Treatment of Industrial Wastewater
Sulphide toxicity due to high concentrations of sulphurous compounds in some industrial wastewaters results in difficulties when using the favourable anaerobic treatment; it even makes anaerobic treatment impossible. Today, several methods are available for control of sulphide toxicity: heavy metal sulphide precipitation, addition of alkali to raise pH and thereby convert the toxic H2S to the less toxic HS-, washing of the biogas to remove H2S and recirculation of the washed gas to remove more H2S, and biological pretreatment for reduction of inorganic sulphurous compounds to sulphide and removal of the produced sulphide. A large number of factors influence the choice of method for control of sulphide toxicity. Thus, no general rules for this choice exist. It can, however, be stated that addition of chemicals for sulphide precipitation or pH control is too expensive for continuous use at high concentrations of sulphurous compounds (beside some other drawbacks). “Complete abstract not presented.”