Treatment of polluted water esp. in the paper-making industry

摘要

Treatment of polluted water comprises: (a) reducing the solids content below 20 mg/l; (b) adjusting the pH to 2-11; (c) reducing the BaSO4 concn. to 10-9 g/l or less and the K2SO4 concn. to 5x10-4 g/l or less; and (d) passing the water through a membrane filtration or nano-filtration unit.