Simultaneous activated sludge wastewater treatment and odour control

Lab-scale tests were used to determine the amount of H2S that can be treate d 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 type s of sludge, but sludge type, e.g. carbonaceous, nitrifying, with or withou t coagulant, affects removal efficiency. The presence of the biomass result ed in greater H2S removal than the use of wet scrubbing and the adverse eff ects on mixed liquor were negligible. A pilot plant was used to study the r emoval efficiencies of activated sludge diffusion using a typical wastewate r treatment plant H2S concentration and investigated the effects that the d iffusion of H2S had on the process performance. Results indicated that the levels of H2S produced by other unit processes on a wastewater treatment si te (approximately 5 ppm) can be treated using activated sludge diffusion wi thout compromising the performance of the wastewater treatment process. The only effects on the activated sludge plant observed were: (1) nitrificatio n was interrupted briefly as H2S diffusion commenced and (2) the species' d iversity in the sludge decreased.