Aminated cellulose doped magnetic manganese ferrite (GC@MnFe2O4) nanocomposite for removal of Allura Red dye from wastewater: RSM optimization

Abstract Organic pollutants discharged from industries contribute to severe water pollution. To enhance the removal of the negatively charged Allura red (E129) dye, we prepared a positively charged novel guanidine-cellulose@manganese ferrite (GC@MnFe 2 O 4 ) nanocomposite that was thoroughly characterized using various techniques such as elemental analysis, Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Brunauer–Emmett–Teller (surface area analysis) (BET) and Vibrating Sample Magnetometry (VSM). GC@MnFe 2 O 4 was employed in the adsorption of Allura red (E129) dye. Response surface methodology (RSM) with Box Behnken Design (BBD) was employed to fine-tune the reaction parameters in order to optimize the adsorption process. A maximum adsorption capacity, for E129, was achieved under the optimal conditions for 10 ml of dye are pH 2.03, E129 concentration of 48.66 mg L −1 , with an adsorbent dosage of 10.33 mg, after at contact time of 15 min, and temperature of 298 K. The spent GC@MnFe 2 O 4 can be regenerated and reused efficiently for up to five adsorption cycles. The adsorption kinetic of E129 dye fitted the Elovich model indicating a rapid initiation of adsorption, which is unusual and suggests a strong affinity between the adsorbate and the adsorbent surface due to extremely high a e indicates that adsorption begins very rapidly, which is uncommon and may indicate a very high affinity between the adsorbate and the adsorbent surface. Additionally, due to magnetic properties, the GC@MnFe 2 O 4 rapid collection within 20–30 s by Nd52 magnet and the Langmuir isotherm model best described the adsorption of E129 dye, with maximum adsorption capacities q e of 21.1 mg g −1 at 298 K. While, the thermodynamic analysis revealed that the adsorption of E129 dye onto GC@MnFe 2 O 4 is a spontaneous exothermic process. The prepared GC@MnFe 2 O 4 was also effectively used to remove E129 dye from actual water samples and synthetic effluents, achieving a recovery rate (R%) exceeding 98%. Ultimately, this study demonstrates that the fast-responsive GC@MnFe 2 O 4 can be effectively utilized to eliminate E129 dye from a wide range of real water sources. Collectively, the results indicate that the as-prepared GC@MnFe 2 O 4 is promising for anionic pollutant adsorption and the removal of anionic dyes, and our mechanistic results are of guiding significance in environmental cleanup. This work contributes significantly to understanding how experimental conditions influence the mechanism of dye adsorption by GC@MnFe 2 O 4 , offering valuable and new insights for future applications and optimizations in the treatment of effluent-containing dyes.