Air Pollutants from Sewage Sludge Incineration

The disposal of sewage sludges is one of the unsolved chronic municipal problems. Further complications are added to the current trend of increasing construction of sewage treatment facilities and restricting ocean dumping. This paper reviews the characteristics of sewage sludges, types of sludge incinerators commercially available, air pollution aspects of sludge incineration, and current regulations and emission standards for sewage sludge incineration. On-site visitations of five sludge incinerators were conducted to assess their actual performance. Source test data are presented to illustrate potential emissions of air pollutants and their control, especially of trace metals in sludges and in stack gases. Environmental considerations may ultimately require the removal of toxic metals from the wastewater prior to entering the public sewer.