Treatment of waste gases contaminated with odorous sulfur compounds

Due to their very low odor threshold value (ppbv range), high toxicity, and potential corrosive effect, the presence of volatile sulfur compounds in waste gases deserves special attention. These sulfur compounds mainly include hydrogen sulfide, dimethyl sulfide, dimethyl disulfide, methanethiol, carbon disulfide, and carbonyl sulfide. Contrary to natural emissions, anthropogenic emissions may contribute to local concentrations, strongly exceeding the odor threshold value. These anthropogenic sources mainly include these processes where anaerobic degradation of organic matter can occur (e.g., waste water treatment and composting plants) and processes where organic matter is heated (e.g., thermal sludge-treatment plants). Industrial applications of volatile sulfur compounds (e.g., for viscose rayon manufacturing) and their production during chemical reactions (e.g., in the Kraft paper pulping process) can also lead to high local atmospheric concentrations. An overview of abatement technologies for aerobic waste gases containing these compounds is presented, including both physicochemical (scrubbing, adsorption, etc.) and biotechnological (biofiltration, biotrickling filtration) methods.