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Wastewater Sludge

Waste Water Treatment

  1. Izrail S. Turoviskiy

Published Online: 15 APR 2005

DOI: 10.1002/047147844X.ww313

Water Encyclopedia

Water Encyclopedia

How to Cite

Turoviskiy, I. S. 2005. Wastewater Sludge. Water Encyclopedia. 1:861–864.

Author Information

  1. Jacksonville, Florida

Publication History

  1. Published Online: 15 APR 2005


The Environmental Protection Agency (EPA) has defined sewage sludge as any solid, semisolid, or liquid residue removed during the treatment of municipal wastewater or domestic sewage, including solids removed during primary, secondary, or advanced wastewater treatment, scum, septage, and sewage sludge products. Instead of using the term sludge, some specialists have used the terms residual, sediments, solids, slime-solid, or biosolids, depending on its condition or its usefulness and whether it meets the applicable criteria for that particular term.

Sludge is a suspension including solid and semisolid materials separated and generated from the liquid wastewater stream of a treatment plant during purification of municipal wastewater, industrial wastewater, or natural water in mechanical, biological, or physicochemical facilities.


  • wastewater sludge;
  • sewage sludge;
  • activated sludge;
  • biosolids;
  • sludge properties;
  • biosolids characteristics