Study on the Methods of Treating Polysilicon Wastewater by Chemical Flocculation

Through the research of FeSO₄, PAC, FeCl₃, Al₂(SO₄)₃ four chemicals effect on the Polysilicon wastewater in this experiment, to determine the coagulants and coagulant type, dosing quantity and dosing conditions. Experimental results show that the 1200 mg/L concentration, PAC coagulation effect is the best, precipitation rate is the highest. To determine the best conditions for coagulation: dosing quantity for each liter of 36mg, PH = 8, stirring speed for 240 r/min, stirring time of 2 min. Through the experiment of PAM optimization determine cationic 1 # PAM for best PAM type, not only was big volume, and settlement body fastest, precipitation, the largest amount on the most clear liquid dosage, clear and the fewest. Join coagulant PAM, sedimentation is more obvious. Sure dosing optimal concentration of 1 g/L, dosing quantity for each liter of 10 ml, best stirring speed for 120 r/min, join PAM coagulation time after need only 10 s, greatly shorten the reaction time, two hours later the highest precipitation rate can reach 85%.