H2S generation in a reclaimed urban wastewater pipe. case study: Tenerife (Spain)

The present work is part of an experimental study carried out in a completely filled gravity pipe, 61 km long, which transports reclaimed urban wastewater (RUWW), for crop irrigation with an average water residence time of 42 h, in the island of Tenerife (Spain). Field studies were conducted from November 1994 to June 1995. H2S generation has been observed in the pipe when anaerobic conditions appear. A direct relation between sulfide generation and the organic matter measured as COD has been seen. S(II) build-up in this pipe is compared with the predicted S(II) according to equations proposed by Boon and Lister (1975), Hvitved-Jacobsen et al. (1988) and Boon (1995) for sewers [Boon, A. G. and Lister, A. R. (1975) Formation of sulphide in rising main sewers and its prevention by injection of oxygen. Prog. Water Technol. 7(2), 289–300; Hvitved-Jacobsen, T., Juette, P. H., Nielsen, P. H. and Jensen, N.Aa. (1988) Hydrogen sulphide control in municipal sewers. In Pretreat. in Chem. Wat. and Wast. Treat., Proceedings of the 3rd International Gothenburg Symposium, eds. H. H. Hahn and R. Klute, pp. 239–247. Springer Verlag, Gothenburg, Sweden; Boon, A. G. (1995) Septicity in sewers: causes, consequences and containment. Water Sci. Technol. 31(7), 237–253.]. Changes in oxidation–reduction potential (ORP) during transportation are presented and an empirical equation which relates S(II) concentration in wastewater with the oxidation–reduction potential (ORP) and sulfate has been developed.