USE OF RAT-BRAIN NA-ATPASE ASSAY TO DETERMINE THE EFFECTIVENESS OF BIOLOGICAL TREATMENT TO REDUCE TOXICITY OF PAPER-MILL EFFLUENTS(, K+)

This work evaluates the toxicity of kraft mill wastewaters and the ext ent of detoxification attained after biological treatment of these eff luents with the fungus Phanerochaete chrysosporium. The degree of inhi bition of the enzyme Na+,K+-ATPase was used as an indicator of toxicit y. The untreated alkali extraction stage effluent significantly inhibi ted the enzyme activity. When this effluent was treated biologically t he degree of enzyme inhibition was practically reduced to zero. The in hibition of the enzyme Na+,K+-ATPase was found to be a suitable indica tor of toxicity for bleached pulp and paper mill waste waters.