Proceedings

Abstract

Sludge conditioning by chemical addition helps remove a large fraction of the free water and in some cases even the bound water. Therefore, adequate conditioning is essential in order to reach acceptable solids content and reducing operational costs.

Equally, additional pre-treatment prior to conditioning does increase solids and water separation if the sludge colloidal cohesion is broken.

This paper presents the results of an Optimisation and Innovation trial at Tarrant Crawford with OREGE (France) SLG (Solid- Liquid-Gas). The trial was ran over a period of 4 weeks on primary, Co-settled and SAS sludge.  The SLG injects compressed air directly into the sludge to increase solid and water separation by changing the rheology of the sludge allowing a higher percentage water to be removed.

The results shown that the technology is able to increase the solid content of the sludge up to 7% dry solids, remove a substantial amount of water with filtrate quality around 500 mg/l while reducing polymer usage, and considerably reduce transport costs.