The characteristics of products from sewage sludge pyrolysis by microwave

Disposal of excess sludge, a secondary waste, from activated sludge process is one of the most serious problems encountered in wastewater treatment. Microwave-induced pyrolysis is a novel method of treating the secondary sludge with production of fuel. The primary goal of this study was to identify the characteristics of products in microwave-induced secondary sludge pyrolysis. The production analysis of gases composition by GC showed that microwave pyrolysis generated gases with a high proportion (up to 55%) of CO and H2, which were considered as important fuel. The oils were composed basically of fatty acids, whose content could be up to 56%. Both oils and gases produced in the microwave pyrolysis showed relatively high overall heating values, which revealing the potential application of these products as fuel. The complex mechanisms that took place during the microwave pyrolysis of secondary sludge were also discussed in this paper.