Modified native cellulose fibers--a novel efficient adsorbent for both fluoride and arsenic.

Native cellulose fibers were surface modified by poly(N,N-dimethyl aminoethyl methacrylate) (PDMAEMA) to generate an anion adsorbent, which was characterized by scanning electron microscopy, fourier transform infrared spectroscopy and elemental analyzer. This adsorbent had high efficiency in removal of F(-), AsO(2)(-) and AsO(4)(3-) from aqueous solutions, even at low initial concentrations. Adsorption kinetics showed that the adsorption equilibrium could be reached within 1 min. The distribution coefficient did not change with adsorbent dose, indicating the adsorption was a homogenous process. Langmuir, Freundlich and Temkin models were used to fit the adsorption isotherms. Based on the parameters calculated from the models, the adsorption capacity was in the order of AsO(4)(3-)≫AsO(2)(-)>F(-), and the adsorption was a favorable process. Compared with Freundlich and Temkin models, the isotherms followed Langmuir model a little better.