Mixts. of spent cutting fluids and water-oil wastewaters were purified by adsorption on hydroxyapatites produced by incineration of bone-meat meals and their calcination at 750 degrees C or 850 degrees C. The adsorption was carried out both on the hydroxyapatite bed at room temp. and at 65 degrees C and under staedy-state conditions. The purifn. under dynamic conditions resulted in decrease in COD by 32-86%, while by 8-52% only under steady-state conditions.