FTIR and XPS Analysis of Characteristics of Synthesized Zeolite and Removal Mechanisms for Cr(III)

Zeolite products were synthesized from fly ash using one-stage method, and the characteristics of zeolite were analyzed with approaches of XRD, SEM and zeta potential, the removal mechanism for Cr(III) was further investigated by FTIR and XPS. From the pH value of 8 to 12, the negative zeta potential of NaP1 zeolite products decreased from -8. 72 to -24.46 mV. The pseudo-second-order kinetics equation and Langmuir isotherm fit better the reaction, the maximum adsorption capacity was 33. 557 0 mg.g(-1). Functional groups of -OH and Si-O were important for Cr(HI) removal shown from FTIR spectra. The Cr(2p(3/2)) peak was found at the binding energy of 576.45 eV, indicating the effectiveness of reaction. The binding energy of Si-Si and Si-O increased by 0. 25 eV and 0. 60 eV, respectively, coordination effect might work between functional groups and Cr(III), and O(1s) binding energy decreased after the adsorption process. The removal for Cr(III) on zeolite was the comprehensive results of physical and chemical adsorption effects.