Control of odorous emissions at wastewater treatment plants - the Singapore experience

Abstract

An extensive field study was carried out to evaluate the performance of various scrubbers under various operating conditions. Several series of 24-hour monitoring field investigations were conducted to provide information on the performance efficiency of the various types of scrubbers. In general, wet scrubbers were able to perform at about 90-95% removal efficiency for H2S and mercaptans while activated carbon columns yielded greater than 98% removal efficiency for these gases. Removal of ammonia compounds were however erratic largely because of the low levels of ammonia concentrations in the airstreams. In terms of odor removal, about 70% of the odor in the different sewage airstreams could be removed effectively by all the types of scrubber systems.