농축기간에 따른 정수슬러지의 탈수성 및 개량 특성 변화

Abstract

The effects of retention time in gravity thickener on the dewatering and conditioning properties of sludges were investigated using settling column of working volume 58 L. Two kinds different water treatment sludges were used, one was taken from the plant treating dam water and the other was from the plant treating river water. SRF was used to evaluate the dewaterability of sludges and two kinds of anionic polymers were used in conditioning experiments of each sludges. The dewaterability of sludge judging from the SRF was improved for the first 5 days in gravity thickening regardless of the sludges. After that, no decrease in SRF (specific resistance to filtration) was observed. An improvement of dewaterability was also confirmed by the measurements bound water content in sludge. The demand of polymer in conditioning was increased with a increase in retention time. Water quality of filtrate was also deteriorated as duration in thickener increased. Further research including the analysis of water content in sludge cake would be needed to investigate the effects of retention time in thickener on sludge dewaterability clearly.