A fresh approach to sludge dewatering using tubular membrane pressing technology

Summary

The traditional disposal routes for sludges from water and sewage works are becoming expensive or unavailable and the satisfactory disposal of sludges is an increasing problem. A woven polyester textile tube forms the heart of a fresh approach to dewatering sludges, the Exxpress process. It has successfully dewatered sludges from dissolved air flotation and from sedimentation processes used for drinking water treatment, producing a firm cake with 10 to 17% w/w dry solids which lost further water by air drying. Sludges from ferric chloride coagulant were less robust than from ferric or aluminium sulphates, leading to poorer quality permeates from the dewatering process. The process performed well on a variety of sludge feed concentrations, at operating pressures around 250 kPa and with cycle times of less than 25 minutes. It represents an economic alternative to the traditional methods of dewatering by pressing, centrifuging or lagooning.

Now the Technical Director of Biotreament Ltd