A method is described use of hydrocolloids for removal of organic and inorganic pollutants from a continuous stream of liquid where chemical composition of the water inhibits the reactants for linking/cross linking hydrocolloids. The method is comprising the steps of enabling said reactants present in the liquid stream and bring them to reaction with the hydrocolloid already brought to attachment with pollutants, where after flock formation allows for separation. Applications of the method are also described.