On the Issue of Air Emissions Control for Sewage Sludge Incinerators: A Short Review

Abstract

Introduction: More than 100 million cubic meters of sewage sludge are accumulated annually at municipal wastewater treatment facilities of the Russian Federation. Its quantity depends on sewage treatment techniques while its qualitative composition is determined by the components of wastewater, efficiency of treatment facilities, and local industries. Sewage sludge contains toxic substances (heavy metal salts, toxic organic matter, etc.) and various types of microorganisms including pathogenic bacteria, all posing hazards to human health and environment. Objective: To summarize and systematize information about fluidized bed incineration of sewage sludge and to compile the list of pollutants emitted by incinerators and subject to control in ambient air. Materials and methods: We used data analysis methods based on review and summarization of up-to-date research data found in Scopus, PubMed, and RSCI abstract and citation databases for 2021–2022. The article selection criterion included the presence of information about effective techniques of sewage sludge disposal. Having reviewed 40 articles, we selected 30 appropriate full-text publications on the topic. Results: We established that incineration is considered to be an effective and universal contemporary method of reducing a large amount of sewage sludge and generating energy. Conclusion: Compared to other techniques of thermal treatment, sewage sludge incineration is promising in terms of equipment and techniques. However, more attention shall be paid to the mechanism of incineration, equipment, temperature conditions, and other factors affecting generation of pollutants, as well as to control of air emissions from sewage sludge incinerators at wastewater treatment plants.