Adsorbing and/or reduction of the amount of organic materials in an aqueous medium by using colloidal precipitated calcium carbonate

A method for adsorbing and/or reducing the amount of at least one organic material in an aqueous medium comprising contacting the aqueous medium with a colloidal precipitated calcium carbonate (cPCC) to adsorb and/or reduce the amount of at least one organic material in the aqueous medium by forming a composite comprising the cPCC and the at least one organic material, and separating the composite from the aqueous medium, wherein the cPCC has a specific surface area of at least 5.0 m2/g, measured using nitrogen and the BET method.