(4)-Morpholinothiosemicarbazide-Modified Cellulose: Synthesis, Structure, Kinetics, Thermodynamics, and Ni(II) Removal Studies.

In this study, cellulose extracted from straw was modified using (4)-morpholinothiosemicarbazide to generate a novel adsorbent as a chelate-complex-based material. The effects of pH, time, temperature, and mass ratios of KIO: cellulose on the yield of the oxidation were analyzed using iodometric titration and photometric methods. The accuracy and precision of the above two methods were evaluated using Student and Fisher statistical distribution. The structure of the material was characterized by Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, and Brunauer-Emmett-Teller surface area analysis. The kinetic order of Ni(II) adsorption was dependent on the concentration of Ni(II). The surface response design enabled to optimize the condition for Ni(II) adsorption at 58 °C, pH of 4.98, within 106 min. The maximum Ni(II) adsorption capacity was 90 mg g. This kind of adsorbent can be reused at least five times without a significant decrease in its adsorption efficiency.