Automation and Optimisation of Centrifuge Sludge Dewatering

Abstract

The dehydration of sewage treatment plant sludges has become one of the major problems in the treatment of waste Water. Very high costs, especially those of flocculation additives, increasingly call for optimisation of this phase of the process. Taking the dewatering of sludge by centrifugation as an example, two different approaches can be considered: mechanical excess sludge thickening without the use of additives and the dehydration of sewage sludge with use of chemical additives. A prerequisite of any automation is the reliable acquisition of data of the parameters required for control. Continuous measurement of the concentration of suspended solids in the sludge that is to be dewatered, of sludge flow and of the turbidity of the clear phase (centrate) leaving the centrifuge, make it possible to design several methods of effective control.