Utilization of municipal wastewater sludge as building and construction materials

Abstract

Sludge is an inevitable by-product of wastewater treatment. Generally, dewatered sludge is disposed of by spreading on the land or by landfilling. For highly urbanized cities, sludge disposal by landfilling might not be appropriate due to limitation of land. Increasingly stringent environmental control regulations have also resulted in limitations on sludge disposal options. Hence, there is an increasing interest in disposal by incineration. Incineration ash will be produced and must be disposed of by other means. The disposal problems can be drastically reduced if sludge can be recycled into building and construction materials. This paper reports the use of sludge and sludge ash as new and non-conventional construction materials as an alternative means of sludge disposal. The properties of the materials made of sludge, the methodology of processing them, and the suitability of the materials for construction applications have been discussed.