Municipal sewage sludge incineration and its air pollution control

Abstract

Municipal sewage sludge is a significant by-product in the conventional treatment of municipal wastewater. Its output has greatly increased with the progress of urbanization and industrialization. The harmless disposal and resource utilization of municipal sewage sludge has become an urgent problem to be solved in the environment field. Incineration is a relatively mature technology for harmless disposal of municipal sewage sludge but faces pollutant emission and high cost problems. In this work, the latest research progress on municipal sewage sludge incineration and its pollutant control is summarized and analyzed systematically. Sludge co-combustion in municipal solid waste incinerators, coal-fired power plants and cement kilns does not require new sludge incineration equipments and flue gas treatment equipments. At the same time, co-combustion is also more environmentally friendly under certain circumstances. Staged air combustion, low oxygen dilution combustion and other methods can optimize combustion and effectively control nitrogen oxide emission during sludge combustion. Ca-based additives have significant effect on sulfur removal. Cl-containing compounds affect the volatilization of heavy metals and the formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans.