Inorganic residual from kraft or soda pulping separated from green liquor in the chemical recovery cycle.

Endpoint summary

Additional information

The main constituents of Green liquor sludge are carbonate, carbon, inorganic sulfur at different oxidation states and sodium and potassium alkaline metal ion, all very common and essential elements in the environment and earth’s crust. Bioaccumulation is not an important or even a relevant issue regarding these inorganic constituents. Practically taken all species tend to regulate internal concentrations of these basic life supporting ions/elements through assimilation, active regulation or adaptation mechanisms.

No testing for bioaccumulation is needed, since the > 0.1 % constituents of green liquor have known low potential for bioaccumulation. However, since GLS is industrial secondary/waste product and consists of separated non process elements (NPE) originating from alkaline pulp cooking and black liquor combustion processes, < 0.1 % of trace constituents known to be bioaccumulative may be present in GLS. (e.g. Polyaromatic hydrocarbons, halogenated organic compounds (AOX <0,6 mg/kg dw, EOX < 1 mg/kg dw) and hazardous heavy metals). It is expected that almost all these minor constituents have known or tested bioaccumulation behavior (e.g. measured or calculated BCF values for organic compounds) and this information can be found in scientific literature and data bases.