Upgrading and uprating of water treatment plants

The paper describes how the contact flocculation-filtra­tion and adsorption system (CFFA) can be used in a staged approach to cost-effectively upgrade existing Water Sup­ply Treatment Works. A case study is presented for modifications to the existing Water Treatment Works at Tokokoe and Befikrom in Ghana. The resulting upgraded plant is designed to be capable of handling a three-fold increase in throughput within the area occupied by the existing works units. The CFFA system has been evaluated and developed from pilot through to full-scale units. Data from operational monitoring of the system modules show consistent per­formance at high throughputs up to three times conven­tional loadings, producing potable water meeting WHO and EC guideline values.