Abstract: Experimental research was made on the treatment of Pb²⁺- containing waste water by combination of diatomite and FeCl₃. The results show than when the water contains 52.4 mg/L , the water can reach the standard for Pb²⁺ content for discharge after the treatment at the conditions of a ratio (mass ratio)of diatomite to FeCl₃ of 6∶1, diatomite dosage of 70 mg/L, pH control at 7.0~8.0, agitation speed of 120~140 r/min and 80 min precipitation. Easy to operate and needing only a small investment, the method has good application prospect.

Key words: Diatomite, Intensified coagulation, WPb²⁺- containing waste water