Release of phosphorus from sewage sludge using microwave technology

Abstract

A novel microwave treatment of sewage sludge was developed as part of the ongoing studies for enhancing the recovery of phosphorus from municipal wastes. The microwave treatment provided a rapid and efficient process to release phosphate from sewage sludge. By using the microwave treatment for only 5 min, up to 76% of the total phosphate in the sludge could be released into the solution. No chemical additions were necessary in the microwave process. After the sewage sludge was microwave treated at a temperature of 100 °C, no microbial activities were observed over a period of 24 h. This microwave process could also be used for the conditioning and stabilization of liquid sludge. Key words: microwave technology, phosphate release, conditioning and stabilization of sludge.