Adsorption of Hexavalent Chromium from an Aqueous Phase by Hydroxypropyl Methylcellulose Modified with Diethylenetriamine

Modified hydroxypropyl methylcellulose was synthesized by hydroxypropyl methylcellulose (HPMC), epichlorohydrin, dimethylformamide (DMF) and diethylenetriamine. The chemical functional groups and morphology of the modified hydroxypropyl methylcellulose (MHPMC) were characterized by the Fourier transform infrared spectroscopy, and scanning electronic microscopy, and the crystal structure of MHPMC was studied by X-ray diffraction analyzer. Additionally, the element composition of the adsorbent was analyzed by the energy dispersive spectrometer, and the factors affecting the adsorption performance, such as time (15-240 min), the amount of adsorbent (0.1-0.8 g), initial concentration of ions (30-350 mg.L-1) and pH (4-7.5) were estimated. Results from the experimental data showed, under the optimum experimental parameters condition like adsorption time (110 min), adsorption quantity (0.4 g), initial ion concentration (100 mg.L-1), and pH (5.5), the adsorption removal rate reached 99.78%. In addition, the adsorption process is well consistent with the quasi-two-stage kinetic model and the Langmuir model, and the negative value of Delta G and the positive value of Delta H denote that the adsorption process of hexavalent chromium loaded on the MHPMC is endothermic and spontaneous.