Flocculation promotor - of sodium alginate prepd by neutralisation of alginic acid

摘要

Flocculation promotor consists of a colloidal suspension in Ca-free water of sodium alginate prepd by neutralisation of alginic acid with Na or Na2CO3 to pH 7.2-6.5. The flocculant is a salt or hydroxide of a trivalent metal. Amt. of alginate required is 0.2 ppm and it is added after the flocculant. Treatable effluent has pH of 6.8-7.5 and contains clay marl. Reduction in free alginic acid content produced by neutralising to this pH gives more consistant flocculation.