Statistical Design and Optimization of Cr (VI) Adsorption onto Native and HNO3/NaOH Activated Cedar Sawdust Using AAS and a Response Surface Methodology (RSM)

Maryam El Hajam; Noureddine Idrissi Kandri; Sadin Özdemir; Gabriel Plavan; Naoufel Ben Hamadi; Fehmi Boufahja; Abdelaziz Zerouale

doi:10.3390/molecules28217271

Statistical Design and Optimization of Cr (VI) Adsorption onto Native and HNO₃/NaOH Activated Cedar Sawdust Using AAS and a Response Surface Methodology (RSM)

Molecules. 2023 Oct 25;28(21):7271. doi: 10.3390/molecules28217271.

Authors

Maryam El Hajam^{1

2}, Noureddine Idrissi Kandri³, Sadin Özdemir⁴, Gabriel Plavan⁵, Naoufel Ben Hamadi⁶, Fehmi Boufahja⁷, Abdelaziz Zerouale²

Affiliations

¹ School of Forest Resources and Advanced Structures and Composites Center, University of Maine, Orono, ME 04469, USA.
² Processes, Materials and Environment Laboratory (PMEL), Faculty of Sciences and Techniques, Sidi Mohammed Ben Abdellah University, Road Imouzzer, Fez BP 2202, Morocco.
³ Signals Systems and Components Laboratory (SSCL), Faculty of Sciences and Techniques, Sidi Mohammed Ben Abdellah University, Road Imouzzer, Fez BP 2202, Morocco.
⁴ Food Processing Programme, Technical Science Vocational School, Mersin University, Mersin 33343, Turkey.
⁵ Department of Biology, Faculty of Biology, Alexandru Ioan Cuza University, Bvd. Carol I. No. 20A, 700505 Iasi, Romania.
⁶ Chemistry Department, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623, Saudi Arabia.
⁷ Biology Department, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623, Saudi Arabia.

Abstract

The removal of heavy metals from wastewater has become the subject of considerable interest at present. Thus, the use of novel adsorbents that are highly efficient is of critical importance for the removal of Cr (VI) ions from aqueous media. The adsorption of Cr (VI) ions from aqueous solutions by a new adsorbent, cedar wood sawdust, and the optimization of its adsorption parameters, were investigated in this study. Cedar wood sawdust was used in its native and HNO₃/NaOH chemically modified forms as new low-cost sorbents to remove Cr (VI) ions from aqueous solutions in a batch system. The adsorption conditions were analyzed via response surface methodology. The RSM results showed that the optimal adsorption conditions yielding the best response were an adsorbent mass of 2 g for native Cedar and 1.125 g for its activated form, a metal concentration of 150 mg/L for native Cedar and 250 mg/L for activated, a temperature of 50 °C, a pH of 1, and a contact time of 67.5 min. At optimum adsorption conditions, the maximum adsorption capacities and the adsorption yields were 23.64 mg/g and 84% for native Cedar and 48.31 mg/g and 99% for activated Cedar, respectively.

Keywords: Cr (VI) removal; batch adsorption; cedar sawdust; chemical activation; optimization; response surface methodology.

Grants and funding

This work was supported and funded by the Deanship of Scientific Research at Imam Mohammad Ibn Saud Islamic University (IMSIU) (grant number IMSIU-RP23071).