Effects of pH on isotherm modeling and cation competition for Cd(II) and Cu(II) biosorption on Myriophyllum spicatum from aqueous solutions

• Published in: Environmental earth sciences Vol. 72; no. 11; pp. 4237 - 4247
• Main Authors: Li, Guoxin, Zhang, Dandan, Li, Qingsong, Chen, Guoyuan
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.12.2014; Springer Berlin Heidelberg; Springer; Springer Nature B.V
• Subjects: Aquatic plants; Aqueous solutions; Biogeosciences; Biomass; biosorption; cadmium; Cations; Competition; Constants; Copper; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Science and Engineering; Exact sciences and technology; Fourier transform infrared spectroscopy; Fourier transforms; Geochemistry; Geology; Heavy metals; Hydrology/Water Resources; Infrared spectroscopy; Ions; Isotherms; Kinetics; Marine and continental quaternary; Mathematical models; Metal ions; Myriophyllum spicatum; Original Article; Pollution, environment geology; Sorption; sorption isotherms; submerged aquatic plants; Surficial geology; Terrestrial Pollution; thermodynamics; pH; Cd(II); Cu(II); Competitive biosorption; models; biomass; cations; Fourier transformation; aqueous solutions; thermodynamics; metals; isotherms; pollution; sorption; Myriophyllum spicatum; cadmium; copper; ions; biogenic effects; equilibrium; kinetics; infrared spectroscopy
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-014-3319-1

The biosorption characteristics of Cd(II) and Cu(II) ions from aqueous solutions obtained using submerged aquatic plant (Myriophyllum spicatum) biomass were investigated in terms of equilibrium, kinetics, thermodynamics, and cation competition. Langmuir and Freundlich models were applied to describe the biosorption isotherm of metal ions by M. spicatum biomass and isotherm constants considering the most important parameter, pH. The variation of sorption isotherm constants showed pH dependence. The Langmuir and Freundlich models fitted the equilibrium data well. The maximum biosorption capacity (q ₘ) of M. spicatum biomass was determined to be 29.07 mg/g for the Cd(II) ion at pH 5.0 and 12.12 mg/g for the Cu(II) ion at pH 6.0. Chi square analysis showed that the Freundlich model fitted the equilibrium data better than the Langmuir isotherm. Competition of Cd(II) and Cu(II) in a binary solution showed that the Langmuir monolayer capacity of Cd(II) decreased from 29.07 mg/g with only Cd(II) in solution to 12.02 mg/g in the presence of Cu(II). Kinetics results showed that the biosorption processes of both metal ions followed the pseudo-second-order kinetics well. The calculated thermodynamic parameters (∆G ⁰, ∆H ⁰, and ∆S ⁰) showed that biosorption of Cd(II) and Cu(II) ions onto M. spicatum biomass was feasible, spontaneous, and endothermic in nature. Fourier transform infrared spectroscopy spectrum analysis revealed that Cd(II) and Cu(II) sorption was mainly ascribed to carboxyl, hydroxyl, amine, and C–N groups in M. spicatum.