Pyrolysis Characteristics Of Sewage Sludge And New Approaches Of Its Utilization

Sewage sludge is the inevitable by-product of municipal sewage treatment. The quantity of sewage sludge is being generated in an ever increasing amount due to rapid urbanization and higher effluent criteria implemented in recent decades, and at the same time, most of the pollutants removed in sewage decontamination processes are contained in the sewage sludge, which, therefore, becomes highly concentrated in contaminants. Without proper treatment and disposal, sewage sludge will cause a secondary pollution and health problem. In recent years, the issues about treatment and disposal of sewage sludge have received greater concerns by the public. According to the more and more strict legislation on the waste discharge to environment, the traditional methods, such as sludge landfill, ocean dumping, cropland application and incineration have been faced with tremendous environmental challenge. It is a tendency to combine contamination control and utilization in the disposal of solid waste; and new approaches of utilizing sewage sludge becomes research hotspots with the effect of contamination control.Sewage sludge disposal is urgently needed in China. Most of produced sewage sludge were ex-situ disposed and did not become non-hazardous to the environment. The ratio of sewage sludge utilization is still quite low. The high cost of disposal has restricted the application of advanced technology and equipment, and it is generally difficult to get anticipated effect because of the difference in sewage sludge. In order to renew the treatment process and meet strict environmental regulations, it is necessary to develop relevant basic research of sewage sludge treatment technique.Based on the research results in the past, holding the current trend of sewage sludge treatment in the world, taking the sewage sludge produced by Wuhan city Wastewater treatment plant for the research object, following the principle of innocuity, minimization and utilization, this paper studied the pyrolysis characteristics and new approaches of sewage sludge utilization, investigated the solidifying effectiveness of heavy metals during the utilization process. This research work has important environmental, economic and social benefit and important scientific implications, providing theoretical basis for pollution control and large scale utilization of sewage sludge in the future.The objective of this work was to minimize and decontaminate the pollution of sewage sludge by heat treatment of the organic components, and to utilize the inorganic components.