Natural and Low-Cost P. turgidum for Efficient Adsorption of Hg(II) Ions from Contaminated Solution: Isotherms and Kinetics Studies

Abstract

Mercury (II) ions (Hg(II)), a potent heavy metal water pollutant, was efficiently removed using a novel adsorbent prepared from Panicum turgidum roots by facile drying. The experimental conditions such as the solution pH, temperature, contact time, and Hg(II) ions initial concentration were screened in the adsorption experiment. The results revealed that the P. turgidum-Hg(II) ions adsorption system was promoted by the high density of active sites and the adsorption process is independent of the adsorbent surface area. Hence, maximum adsorption capacity of 333.33 mg/g of Hg(II) ions was achieved at 30 °C. The adsorption experimental data for isotherm and kinetic studies best fitted the Freundlich isotherm and pseudo-first-order model with R2 of 0.985 and 0.991, respectively. The results indicate that P. turgidum can efficiently remove Hg(II) ions from contaminated solutions and a potential wastewater treatment adsorbent.