Forecasting of H₂S build-up in a reclaimedwastewater pipe Available to Purchase

The present study has been carried out in a completely filled gravity pipe, 61 km long, which transports reclaimed urban wastewater (RUWW), for crop irrigation in the island of Tenerife (Spain), at an average water velocity of 0.4 m/s. Due to the long residence time of the reclaimed wastewater in the pipe (40 hours), anaerobic conditions usually appear, and chemical transformation of reclaimed wastewater occurs during transportation, especially sulfide generation. Field studies have been conducted from November 1994 to January 1997. The variation in sulfide and oxidation-reduction potential (ORP) among other parameters during wastewater transportation have been reported. The object of this work is to study the kinetics of the sulfide generation in a full scale reclaimed wastewater pipe, in order to obtain a forecasting equation of sulfide generation, and to compare this equation with those previously proposed for raw wastewater sewers. Equations obtained from this research differ quite from those previously proposed for sewers. This can be due to the reclaimed wastewater used in this system, which has a very much lower organic matter content than raw wastewater.