Evaluation efficiency of Iranian natural zeolites and synthetic resin to removal of lead ions from aqueous solutions
Malihe Moazeni, Saeed Parastar, M Mahdavi, Afshin Ebrahimi
Abstract
Abstract Heavy metal such as Pb 2+ (lead ions) has high toxicity potential, and it can be dangerous for public health and environment. The ion exchange process is one of the methods that can be used for Pb 2+ removal from aqueous solutions. The aim of this study was to investigate the removal efficiency of Pb 2+ from the synthetic aqueous solutions using Iranian natural zeolite (INZ) (Clinoptilolite) in comparison with a synthetic resin (SR). In this study, the removal of Pb 2+ from aqueous solution investigated by INZ and synthetic resin under different experimental conditions. Parameters like initial Pb 2+ concentration, contact times, adsorbent dosage, pH and size particles of INZ, and best-fitted isotherm were studied. The results showed that the most removal efficiency of Pb 2+ with INZ was obtained at pH 3–5, contact time 15–60 min, adsorbent dosage 20–50 g/L, Pb 2+ initial concentration 25 mg/L, and the removal efficiency was increased with decreasing INZ particle size. The high removal of Pb 2+ with SR was at pH 4–6, for 25 mg/L initial Pb 2+ concentration at 15–60 min and 5–10 g/L SR. Isotherms study with ISOFT software indicates that the Freundlich and Langmuir isotherms expression provides the best fit for Pb 2+ sorption by INZ and SR, respectively. This study indicated that for Pb 2+ ion removal, the SR was more efficient than INZ for high concentration solutions; however, in low concentration of Pb 2+ , the removal efficiency was approximately equal.