WATER TREATING FLOCCULANT FOR COLD WATER AND PURIFYING TREATMENT METHOD FOR COLD WATER USING THE FLOCCULANT

摘要

PURPOSE: To provide a water treating flocculant which has excellent flocculating effect even on cold water whose temperature is as low as 10°C or lower and provide cold water purifying treatment method using the water treating flocculant. ;CONSTITUTION: A flocculant can have high flocculating effect on cold water by setting basicity of aluminum polychloride to be 60-70% and the sulfate ion weight ratio (SO₄/Al₂O₃) to be 0.35-0.6 and thus making the flocculant have high basicity and high sulfate ion concentration. The addition amount necessary to decrease the turbidity of raw water at 2°C, for example, to 1ppm from 6ppm is 100ppm for a conventional one (see a curve 4). As compared with that, even if the sulfate ion is the same level (2.8%) as that of the conventional one, 75ppm of the flocculant having high basicity (see a curve 1) is enough and if the concentration is increased, 50ppm and 45ppm of the flocculant (see a curve 2 and a curve 3, resp.) are enough and the amounts are the same as or less than the amount necessary at 20°C for the conventional one.;COPYRIGHT: (C)1995,JPO