[Control of residual humic acid and residual aluminium in water with enhanced coagulation].

Control of residual humic acid and residual aluminium in water with enhanced coagulation was investigated. The influence of various factors on the coagulation was studied, in order to reach the maximum humic acid removal and the minimum aluminium residue simultaneously. Results showed that residual humic acid was controlled below 0.04 cm(-1) and residual aluminium kept at about 0.1 mg/L in water with pH value between 6 and 6.5, the AlCl3 dosage of 0.5 x 10(-3) mol/L, under the temperature of 20 degrees C. Addition 0.01 mol/L of CaCl2 could improve the enhanced coagulation effect. Because the suspended granule concentration changes with seasons, the influence of the kaoline dosage on the humic acid removal process was studied.