Reuse of Municipal Wastewater Sludge for Construction Material

Treatment of municipal wastewater results worldwide in the production of large amounts of sewage sludge. The major part of the dry matter content of this sludge consists of nontoxic organic compounds, in general a combination of primary sludge and secondary (microbiological) sludge. The sludge also contains a substantial amount of inorganic material and a small amount of toxic components. The large volume of wastewater sludge generated requires enormous landfill space for disposal. Diverting the wastewater sludge from landfill would alleviate the shortage of landfill sites. Thus alternative applications have to be considered for the wastewater sludge diverted away from the landfills. The use of wastewater sludge for the production of construction materials is reviewed in this paper. Wastewater sludge can be used as raw materials for making bricks, concrete filler and concrete aggregates. The study reveals that the reuse of wastewater sludge as construction materials offers a technically feasible alternative for sludge disposal.