Flax fiber based semicarbazide biosorbent for removal of Cr(VI) and Alizarin Red S dye from wastewater

• Published in: Scientific reports 2023-05, Vol.13 (1), p.8267-8267, Article 8267
• Main Authors: Akl, Magda A., El-Zeny, Abdelrahman S., Hashem, Mohamed A., El-Gharkawy, El-Sayed R. H., Mostafa, Aya G.
• Format: Article
• Language: English
• Subjects: 639/638/11; 639/638/169; 639/638/224; 639/638/298; 639/638/455; 639/638/549; 639/638/898; Adsorption; Cellulose; Chromium; Dyes; Fourier transforms; Humanities and Social Sciences; Infrared spectroscopy; Isotherms; multidisciplinary; Potassium carbonate; Scanning electron microscopy; Science; Science (multidisciplinary); Semicarbazide; Wastewater; X-ray diffraction
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-34523-y

In the present study, flax fiber based semicarbazide biosorbent was prepared in two successive steps. In the first step, flax fibers were oxidized using potassium periodate (KIO 4 ) to yield diadehyde cellulose (DAC). Dialdehyde cellulose was, then, refluxed with semicarbazide.HCl to produce the semicarbazide functionalized dialdehyde cellulose (DAC@SC). The prepared DAC@SC biosorbent was characterized using Brunauer, Emmett and Teller (BET) and N 2 adsorption isotherm, point of zero charge (pH PZC ), elemental analysis (C:H:N), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses. The DAC@SC biosorbent was applied for the removal of the hexavalent chromium (Cr(VI)) ions and the alizarin red S (ARS) anionic dye (individually and in mixture). Experimental variables such as temperature, pH, and concentrations were optimized in detail. The monolayer adsorption capacities from the Langmuir isotherm model were 97.4 mg/g and 18.84 for Cr(VI) and ARS, respectively. The adsorption kinetics of DAC@SC indicated that the adsorption process fit PSO kinetic model. The obtained negative values of ΔG and ΔH indicated that the adsorption of Cr(VI) and ARS onto DAC@SC is a spontaneous and exothermic process. The DAC@SC biocomposite was successfully applied for the removal of Cr(VI) and ARS from synthetic effluents and real wastewater samples with a recovery (R, %) more than 90%. The prepared DAC@SC was regenerated using 0.1 M K 2 CO 3 eluent. The plausible adsorption mechanism of Cr(VI) and ARS onto the surface of DAC@SC biocomposite was elucidated.