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    Öğe
    Magnetic cellulose-based composite as a new effectively reusable biosorbent for cationic dye removal: Batch and lab-scale column studies
    (Springer, 2023) Dogan, Deniz; Ariff, Azmah Hanim Mohamed; Leman, Zulkiflle; Metin, Ayseguel Ulku
    This study presents a functional magnetic cellulose-based nanocomposite (mCNF(AP)/PMAA) to develop a highly efficient and sustainable adsorbent to remove organic dyes from an aqueous solution. Cellulose was extracted from Arenga Pinnata (AP) and was modified with 2,2,6,6-Tetramethyl-1-piperidinyloxy (TEMPO) to convert carboxyl end groups on cellulose chains that contribute to magnetization reaction. Methacrylic acid, an environmentally friendly monomer carrying carboxylic acid functional groups, was grafted on magnetic cellulose for effective cationic dye removal. The mCNF(AP)/PMAA nanocomposite structure was characterized by XRD, SEM/EDS, TGA, VSM, and FTIR. X-ray diffraction patterns indicated the successful extraction of cellulose from AP and the incorporation of the magnetic core. The SEM/EDS examinations referred to the existence of Fe3O4 nanoparticles and the grafting of PMAA on the surface of magnetic cellulose. At the same time, VSM results demonstrated that the saturation magnetization value of mCNF(AP)/PMAA was 15.5 emu/g, enabling the nanocomposite can be rapidly and easily separated from the aqueous solution under an external magnetic field. The adsorption and desorption behavior of mCNF(AP)/PMAA in batch and continuous lab-scale systems were evaluated using isotherm and kinetic models. The adsorption study revealed that the pH did not significantly affect on adsorption behavior of MB and the maximum adsorption capacity of mCNF(AP)/PMAA was 201 mg/g. The adsorption kinetic and isotherm models were well-fitted to the pseudo-second-order model and Langmuir isotherm. Notably, the regeneration performance of the mCNF(AP)/PMAA was excellent and protected its 75% capacity after the fifteenth adsorption/desorption cycle. The fixed column was used to determine the real-time behavior of the adsorbent in lab-scale continuous mode and the data were analyzed in models such as Thomas, Adams, and Yoon Nelson. The maximum adsorption capacity was found to be 264.65 mg/g. In conclusion, mCNF(AP)/PMAA composite is an effective and cheap material from sustainable sources. Due to its high regeneration and reusability capability, it could be employed as an effective adsorbent in removing pollutants from wastewater.
  • [ X ]
    Öğe
    Mechanical and thermal properties of recycled polyethylene/surface treated hemp fiber bio-composites
    (Wiley, 2023) Guney, Olcay; Bilici, Ibrahim; Dogan, Deniz; Metin, Ayseguel Ulku
    Hemp is a good option for polyethylene additives because of its high cellulose and fibrous content. This study aims to modify natural hemp fibers with the maleic anhydride/ionic liquid method, manufacture the composites, and compare the thermal and mechanical properties of natural hemp fiber and hemp cellulose. In this study recycled polyethylene as a binder, and filling ratios between 0 and 50 (wt/wt)% are investigated as a parameter. Differential scanning calorimeter and thermomechanical analysis were performed, and it was determined that the coefficient of thermal expansion from 973 to 147 ppm/K. It was determined that the strength of composite materials obtained from cellulose fibers with maleic anhydride/liquid ionic modification improved by around 20% from 19.5 to 24.4 MPa. In addition, as a result of scanning electron microscope analyses performed on the fractured surfaces, it was determined that the pressure, temperature, and time were suitable for producing composite materials. This work shows the potential of recycled polyethylene/ hemp composites as a sustainable green material with simple fabrication procedure and useful mechanical and thermal properties.