Magnetic cellulose-based composite as a new effectively reusable biosorbent for cationic dye removal: Batch and lab-scale column studies

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.

Automated summary

This study presents a functional magnetic cellulose-based nanocomposite (mCNF(AP)/PMAA) as a highly efficient and sustainable adsorbent for removing organic dyes from water. The mCNF(AP)/PMAA composite can be easily separated from the aqueous solution under a magnetic field, and it exhibits excellent regeneration and reusability capabilities. It is a promising adsorbent for pollutant removal from wastewater.