Process for water purification and for the separation of beneficial materials that are obtained from an aqueous solution, comprising determining a turbidity index and adding to the water or to said solution a composition comprising one or more natural or mixtures of natural substances, chosen from the group consisting of substances having a cationic molecular charge and substances having an anionic molecular charge, in an amount determined as a function of said turbidity index, thereby, allowing water purification and the aggregation of said beneficial materials