USING A WATER-INSOLUBLE AMPHOTERIC STARCH TO SIMULTANEOUSLY ADSORB HEAVY-METAL IONS PHENOL FROM SOLUTIONS

An investigation was undertaken regarding the adsorption of heavy metal ions (CrO42- or Pb2+) and phenol from solution with a highly crosslinked amphoteric starch containing the phosphate anionic group and the tertiary amine cationic group. The adsorption process was found to be dependent on initial pH and concentration for both metal ions, and to be concentration-independent for the phenol organic substance. The adsorption follows the Langmuir adsorption isotherm for CrO42-, and the Freundlich adsorption isotherm for Pb2+. The adsorption mechanism confirms that the Na+ of the sodium phosphate group and the Cl- of the tertiary amine group are used to exchange Pb2+ and CrO42- ions, respectively, and the tertiary amine group is used to adsorb phenol.