Rocznik Ochrona Środowiska 2026, vol. 28, pp. 806-816
Suaad Fanos Thani, Melad Khalaf Mohammed 
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University of Wasit, Iraq |
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https://doi.org/10.54740/ros.2026.055 |
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Nano-calcium oxide (CaO) was synthesized from waste chicken eggshells by calcination. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), electron microscopy, N₂ adsorption–desorption analysis and zeta-potential measurements. The cubic nanoparticles had a crystallite size of 24 nm, calculated from the XRD data using the Scherrer equation, and a specific surface area of 85.4 m² g⁻¹. Pb(II) and Cd(II) were removed most efficiently at pH 5.0–6.0 (initial metal concentration 100 mg L⁻¹, adsorbent dose 0.6 g L⁻¹, 298 K), reaching equilibrium within 60 min. Adsorption followed pseudo-second-order kinetics (R² > 0.999) and the Langmuir isotherm, with maximum capacities of 242.7 mg g⁻¹ for Pb(II) and 186.3 mg g⁻¹ for Cd(II) at 298 K. The process was spontaneous and endothermic. Box–Behnken optimization (pH 6.2, dose 0.65 g L⁻¹, contact time 55 min) achieved more than 99% simultaneous removal, and the adsorbent retained about 90% of its capacity after five regeneration cycles. Removal proceeds mainly through ion exchange, surface precipitation and complexation, making eggshell-derived nano-CaO a sustainable, high-performance adsorbent for heavy-metal-contaminated water.
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nano-calcium oxide, adsorption, lead, cadmium, Box–Behnken design
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AMA Style
Thani S.F., Mohammed M.K. Efficient Removal of Lead (II) and Cadmium (II) from Aqueous Solution Using Eggshell-derived nano-calcium oxide: Kinetics, Isotherms, and Statistical Optimization. Rocznik Ochrona Środowiska. 2026; 28:806-816. https://doi.org/10.54740/ros.2026.055
ACM Style
Thani S.F., Mohammed M.K. 2026. Efficient Removal of Lead (II) and Cadmium (II) from Aqueous Solution Using Eggshell-derived nano-calcium oxide: Kinetics, Isotherms, and Statistical Optimization. Rocznik Ochrona Środowiska. 28, 806-816. DOI:https://doi.org/10.54740/ros.2026.055
ACS Style
Thani S.F.; Mohammed M.K. Efficient Removal of Lead (II) and Cadmium (II) from Aqueous Solution Using Eggshell-derived nano-calcium oxide: Kinetics, Isotherms, and Statistical Optimization. Rocznik Ochrona Środowiska 2026, 28, 806-816. https://doi.org/10.54740/ros.2026.055
APA Style
Thani, S. F., & Mohammed, M. K. (2026). Efficient Removal of Lead (II) and Cadmium (II) from Aqueous Solution Using Eggshell-derived nano-calcium oxide: Kinetics, Isotherms, and Statistical Optimization. Rocznik Ochrona Środowiska, 28, 806-816. https://doi.org/10.54740/ros.2026.055
ABNT Style
THANI S.F.; MOHAMMED M.K. Efficient Removal of Lead (II) and Cadmium (II) from Aqueous Solution Using Eggshell-derived nano-calcium oxide: Kinetics, Isotherms, and Statistical Optimization. Rocznik Ochrona Środowiska, v. 28, p. 806-816, 2026. https://doi.org/10.54740/ros.2026.055
Chicago Style
Suaad Fanos Thani and Melad Khalaf Mohammed. 2026. "Efficient Removal of Lead (II) and Cadmium (II) from Aqueous Solution Using Eggshell-derived nano-calcium oxide: Kinetics, Isotherms, and Statistical Optimization". Rocznik Ochrona Środowiska 28, 806-816. https://doi.org/10.54740/ros.2026.055
Harvard Style
Thani S.F. and Mohammed M.K. (2026) "Efficient Removal of Lead (II) and Cadmium (II) from Aqueous Solution Using Eggshell-derived nano-calcium oxide: Kinetics, Isotherms, and Statistical Optimization", Rocznik Ochrona Środowiska, 28, pp. 806-816. doi:https://doi.org/10.54740/ros.2026.055
IEEE Style
S. F. Thani and M. K. Mohammed, "Efficient Removal of Lead (II) and Cadmium (II) from Aqueous Solution Using Eggshell-derived nano-calcium oxide: Kinetics, Isotherms, and Statistical Optimization", RoczOchrSrod, vol. 28, pp. 806-816, 2026. https://doi.org/10.54740/ros.2026.055