Competitive adsorption of Cu(II) and Pb(II) ions from aqueous solutions by Ca-alginate immobilized activated carbon and Saccharomyces cerevisiae

LU Ming(卢明)^{1, 2}, LIU Yun-guo(刘云国)^{1, 2}, HU Xin-jiang(胡新将)^{1, 2}, BEN Yue(贲月)^{1, 2}, ZENG Xiao-xia(曾晓霞)^{1, 2}, LI Ting-ting(李婷婷)^{1, 2}, WANG Hui(王慧)^{1, 2}

(1. College of Environmental Science and Engineering, Hunan University, Changsha 410082, China;
2. Key Laboratory of Environmental Biology and Pollution Control Ministry of Education (Hunan University), Changsha 410082, China)

Abstract:To establish a theoretical foundation for simultaneous removal of multi-heavy metals, the adsorption of Cu(II) and Pb(II) ions from their single and binary systems by Ca-alginate immobilized activated carbon and Saccharomyces cerevisiae (CAS) was investigated. The CAS beads were characterized by Scanning electron microscope (SEM) and Fourier transformed infrared spectroscopy (FTTR). The effect of initial pH, adsorbent dosage, contact time and initial metal ions concentration on the adsorption process was systematically investigated. The experimental maximum contents of Cu(II) and Pb(II) uptake capacity were determined as 64.90 and 166.31 mg/g, respectively. The pseudo-second-order rate equation and Langmuir isotherm model could explain respectively the kinetic and isotherm experimental data of Cu(II) and Pb(II) ions in single-component systems with much satisfaction. The experimental adsorption data of Cu(II) and Pb(II) ions in binary system were best described by the extended Freundlich isotherm and the extended Langmuir isotherm, respectively. The removal of Cu(II) ions was more significantly influenced by the presence of the coexistent Pb(II) species, while the Pb(II) removal was affected slightly by varying the initial concentration of Cu(II). The CAS was successfully regenerated using 1 mol/L HNO₃ solution.

Key words:competitive adsorption; Cu(II); Pb(II); Saccharomyces cerevisiae; kinetics; equilibrium isotherms