Mechanical Dewatering and Thermal Drying of Sludge in a Single Apparatus

This article describes the Centridry (R) technology (marketed in the UK by Euroby Ltd.) used at the Monsanto wastewater treatment plant in Antwerp, Belgium, for handling excess wastewater-activated sludge. In one single enclosed machine, sludge with an initial solids concentration of 1.5 to 4%w/w dry substance is mechanically dewatered with a high-solids decanter centrifuge and thermally dried in a flash dryer, yielding a final product with a concentration of solids ranging from 80 to 95%w/w dry substance. Operational experience with varying sludge characteristics affecting the fouling sensitivity of the system is presented for the Centridry technology at the Monsanto plant in Antwerp.