Simultaneous activated sludge wastewater treatment and odour control Available to Purchase

Lab-scale tests were used to determine the amount of H₂S that can be treated using a range of different activated sludges. Static vessels were used to study the effects of different H₂S concentrations (5, 25, 50 and 75 ppm). The data indicated that odour control may be carried out using certain types of sludge, but sludge type, e.g. carbonaceous, nitrifying, with or without coagulant, affects removal efficiency. The presence of the biomass resulted in greater H₂S removal than the use of wet scrubbing and the adverse effects on mixed liquor were negligible. A pilot plant was used to study the removal efficiencies of activated sludge diffusion using a typical wastewater treatment plant H₂S concentration and investigated the effects that the diffusion of H₂S had on the process performance. Results indicated that the levels of H₂S produced by other unit processes on a wastewater treatment site (approximately 5 ppm) can be treated using activated sludge diffusion without compromising the performance of the wastewater treatment process. The only effects on the activated sludge plant observed were: (1) nitrification was interrupted briefly as H₂S diffusion commenced and (2) the species' diversity in the sludge decreased.