Adsorption removal of Pb²⁺ and Cd²⁺ on lignocellulose-g-acrylic acid/montmorillonite nanocomposite from aqueous solutions

Abstract

Lignocellulose-g-acrylic acid/montmorillonite nanocomposite materials (LNC-g-AA/MMT) was used as an adsorbent to remove Pb²⁺, Cd²⁺ ions from the aqueous solutions_. The effects of various experimental conditions including initial metal ions concentration, initial solution pH, contact time, and temperature were investigated. The data showed that 0.1 g of LNC-g-AA/MMT, 0.04 mol/L of Pb²⁺, and 0.05 mol/L of Cd²⁺, pH 5.5, contact time of 120 and 60 min at 30°C, a maximum adsorption capacity of Pb²⁺ (918.2 mg/g) and Cd²⁺ (482.5 mg/g) were observed. The adsorption kinetics and isotherms have been studied, which implied that all absorption processes were in good agreement with the pseudo-second-order model and the Langmuir isotherm, respectively. The desorption process was also studied. The results indicated that the desorption capacity of LNC-g-AA/MMT for Pb²⁺ and Cd²⁺ was 821.9 and 448.2 mg/g with 0.1 g metal ions-loaded adsorption, 0.06 and 0.04 mol/L of HNO₃ concentration, contact time 60 min, contact temperature 30°C, in which the maximum desorption percentage was 90 and 92.9%, respectively.

Keywords:

• Lignocelluloses
• Montmorillonite
• Nanocomposite
• Adsorption
• Pb²⁺
• Cd²⁺

Acknowledgments

This work was financially supported by the Natural Science Foundation of Inner Mongolia (No. 2012MS0606), Excellent Young Scientist Foundation of Inner Mongolia Agricultural University of China (No. 2014XYQ-12), Inner Mongolia Agricultural University outstanding youth science foundation, and program for young talents of science and technology in universities of Inner Mongolia autonomous region.