University of Missouri Extension

EQ449, Reviewed July 2017

Biosolids Glossary of Terms

Bob Broz
Extension Water Quality State Specialist
Division of Food Systems and Bioengineering

Municipalities and privately owned wastewater treatment facilities process domestic wastewater into sludge and effluent. The sludge is then processed into a secondary resource, biosolids, which has value for land application as a supply of plant nutrients and organic matter.

This guide defines the common terms applied to the generation and land application of biosolids. Consistent use of the correct terminology leads to a clearer understanding. For example, the definition of sludge includes biosolids. However, all sludges are not biosolids. Some sludges are excluded from land application; whereas a sludge defined as biosolids may be land applied.


This guide was previously named WQ449, Biosolids Glossary of Terms. The original authors are Randall Miles and J.R. Brown, University of Missouri, School of Natural Resources; Ken Arnold, Chief of Land Application, Missouri Department of Natural Resources.
EQ449 Biosolids Glossary of Terms | University of Missouri Extension

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