Studies on Treatment of Dyeing Wastewater with
Polysilic Aluminium Ferric Flocculants
ABSTEACT
Treatment of dyeing wastewater is one of the few major problem areas in the current industrial wastewater treatment. Through the experiment flocculation effect affecting the main factors, dyeing treatment by using polysilicate aluminum ferric (PSAF) as coagulant was studied. The optim altreatment conditions with the combined coagulant system were investigated, such as coagulant dosage, Al/Fe mole ratio, acidity of waste water. Experimental results show that the optimal parameters were polysilicate aluminum ferric: the best pH was 7.0, Al/Fe mole ratio was 3/1, dosage of 64mg/L, the best removal of decolorization rate, SS and CODCr was 79.70%, 83.20% and 73.30%. In comparison with the conventional coagulants , such as PAC (polyaluminium chloride) and PFS (polyferric sulfate) , the coagulation performance of PSAF is characterized by higher settlement rate, smaller sludge volume , lower remains of pollutants in the treater dyeing effluent and lower cost of treatment.