Study on the Adsorption Kinetics and Isotherms of Cr(VI) of PVDF/ATP Hybrid Membrane

Poly (vinylidene fluoride)/attapulgite (PVDF/ATP) hybrid membrane was prepared for removal of Cr (VI) ions from wastewater with PVDF as matrix and ATP as adsorbent which was functionalized by cetyl trimethyl ammonium bromide (CTAB) and then modified by tannins (TA). The adsorption kinetics and equilibrium isotherms of the hybrid membranes were particular concerned. The results indicated that the PVDF/ATP membrane displayed a good adsorption capacity for Cr (VI) ions, the adsorption equilibrium could be established within 5 hours and the maximum adsorption capacity was 21.4 mg/g. The adsorption kinetics fit well with Lagergren second-order equation and the adsorption isotherms can be well described by Langmuir and Freundlich models.