Sulfide production and wastewater quality in pressure mains

An empirical model for predicting sulfide production in pressure mains (Hvitved-Jacobsen et al., 1988) was evaluated and modified based on results obtained from two intercepting pressure mains located in the Northern part of Jutland, Denmark. Mass balances in pipe influent and effluent were made for volatile fatty acids, VFA (formate, acetate, propionate and butyrate), dissolved COD, DOC and sulfide and biofilm surface rate for sulfide and organic matter were calculated. Relatively high sulfide formation rates were observed at low temperatures (5-12 degrees C). The sulfide production rate strongly depended on wastewater quality in terms of VFA and dissolved carbohydrate concentration. Based on these two sets of observations wastewater quality and temperature - the original empirical model was modified. (C) 1998 IAWQ. Published by Elsevier Science Ltd.