Removal of aluminum by compound bioflocculant from low turbidity source water

In view of higher concentration of residual Al in the clarified water in the treatment of low turbidity source water by conventional inorganic flocculent, compound bioflocculant (CBF) is used to treat the low turbidity raw water taken from the reservoir in North China in winter. Both jar test and pilot scale flocculation treatment processes are investigated for removing the residual Al from low turbidity water. The test results of the coagulation show that CBF has an effective performance in residual Al removal. Residual Al removal is enhanced by the combination of CBF and polymerized aluminium ferrum chloride (PAFC), CBF restrains the escalating trend of residual Al caused by the Al from PAFC, the concentration of residual Al is 0.016 mg/L. Based on an overall analysis of residual Al removal efficiency and the dosage of flocculant, the optimal dosage for treatment of low turbidity water is CBF=2 mg/L and PAFC=15 mg/L.