Influence of cation leaching on water retentivity of drinking water sludge

摘要

Drinking water sludge (DWS) is discharged during water purification. It is presently classifiedrnas industrial waste. To use DWS in geotechnical works safely, it is important to focus on changeable water retentionrnof DWS. This study investigated the influence of cation leaching to water retentivity of DWS. Cationrnleaching was simulated using column leaching tests. As a result, the water retentivity of DWS decreased afterrncation leaching. It was discussed that the hydrophilic part of flocculating agent used in water purificationrnprocess was deformed by interaction with water and leached as Al. One calculation result showed that thernchange of water retention of DWS occurred around 7 years from the utilization. Therefore, it is beneficial tornmonitor the geotechnical utilization of DWS from the viewpoint of changeable water retentivity.