Biosorption Potential of Arachis hypogaea-Derived Biochar for Cd and Ni, as Evidenced through Kinetic, Isothermal, and Thermodynamics Modeling

Fozia Batool; Rahman Qadir; Fatima Adeeb; Samia Kanwal; Ehab A Abdelrahman; Sobia Noreen; Bedur Faleh A Albalawi; Muhammad Mustaqeem; Muhammad Imtiaz; Allah Ditta; Humaira Yasmeen Gondal

doi:10.1021/acsomega.3c02986

Biosorption Potential of Arachis hypogaea-Derived Biochar for Cd and Ni, as Evidenced through Kinetic, Isothermal, and Thermodynamics Modeling

ACS Omega. 2023 Oct 18;8(43):40128-40139. doi: 10.1021/acsomega.3c02986. eCollection 2023 Oct 31.

Authors

Affiliations

¹ Institute of Chemistry, University of Sargodha, Sargodha 40100, Pakistan.
² Department of Chemistry, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623, Saudi Arabia.
³ Chemistry Department, Faculty of Science, Benha University, Benha 13518, Egypt.
⁴ Department of Biology, University of Tabuk, Tabuk 47512, Saudi Arabia.
⁵ Soil and Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad 38000, Pakistan.
⁶ Department of Environmental Sciences, Shaheed Benazir Bhutto University Sheringal, Upper Dir, 18000, Pakistan.
⁷ School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia.

Abstract

Biochar derived from plant biomass has great potential for the decontamination of aqueous media. It is the need of the hour to test biochar derived from economical, easily available, and novel materials. In this regard, the present study provides insight into the sorption of two heavy metals, i.e., cadmium (Cd) and nickel (Ni), using native Arachis hypogaea and its biochar prepared through pyrolysis. The effect of different factors, including interaction time, initial concentration of adsorbate, and temperature, as well as sorbent dosage, was studied on the sorption of Cd and Ni through a batch experiment. Characterization of the native biowaste and prepared biochar for its surface morphology and functional group identification was executed using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Results revealed the presence of different functional groups such as -OH on the surface of the adsorbent, which plays an important role in metal attachment. SEM reveals the irregular surface morphology of the adsorbent, which makes it easy for metal attachment. Thermogravimetric analysis shows the stability of A. hypogaea biochar up to 380 °C as compared with native adsorbent. The adsorption efficacy of A. hypogaea was found to be higher than that of native A. hypogaea for both metals. The best adsorption of Cd (94.5%) on biochar was observed at a concentration of 40 ppm, an adsorbent dosage of 2 g, a contact time of 100 min, and a temperature of 50 °C. While the optimum conditions for adsorption of Ni on biochar (97.2% adsorption) were reported at a contact time of 100 min, adsorbent dosage of 2.5 g, initial concentration of 60 ppm, and temperature of 50 °C. Results revealed that biochar offers better adsorption of metal ions as compared with raw samples at low concentrations. Isothermal studies show the adsorption mechanism as physical adsorption, and the negative value of Gibb's free energy confirms the spontaneous nature of the adsorption reaction. An increase in entropy value favors the adsorption process. Results revealed that the sorbent was a decent alternative to eliminate metal ions from the solution instead of costly adsorbents.