2012 Volume 68 Issue 2 Pages 286-296
It is important for waste management and sound material-cycle society to clarify the change of the physico-chemical properties of reusable material. In this study, the influence of cation leaching on water retentivity of drinking water sludge was investigated. The column leaching test was executed using drinking water sludge to simulate rainwater percolation, and the water retentivity test of the degraded sludge was executed. As a result, the water retentivity of drinking water sludge decreased after cation leaching. The cation exchangeable capacity of drinking water sludge and its microscopic structure were almost stable during the leaching test. The results indicate a possibility that Al leaching decreases the hydrophilic part of flocculating agent which relates to water retention of drinking water sludge.