Biosolids may be defined as organic wastewater solids that can be reused after suitable sewage sludge treatment processes leading to sludge stabilization such as anaerobic digestion and composting...


However, informal use describes a broad range of semi-solid organic products produced from sewage or sewage sludge.

Sewage sludge contains every toxic chemical known, industries are dumping their waste material in to local sewage water plants which are not designed to remove these hazardous  materials. Sewage slush is the most pollutant waste mixture of the 21st-century.