Sewage sludge

found: Rink, R. Biosolids and septage handling and use in Idaho, 1997(Biosolids is the solid or nearly-solid material created from the biological treatment of community wastewater ... Until recently, the solid material from wastewater treatment was commonly referred to as sewage sludge. However, the term "biosolids" has gradually been accepted as a better descriptor of its character and value.)

found: McGraw-Hill dict. sci. tech.(biosolid: a recyclable primarily organic solid material produced by wastewater treatment processes; sewage sludge: a semiliquid waste with a solid concentration in excess of 2500 parts per million, obtained from the purification of municipal sewage)