Removal of iron, copper, and lead from aqueous solutions with zeolite, bentonite, and steel slag

ABSTRACT

The removal efficiency of lead, iron, and copper ions from aqueous solutions with the use of zeolite, bentonite, and steel slag as adsorbents was investigated. Adsorption experiments were conducted at room temperature with aqueous solutions of individual metal ions of lead, copper, and iron, and an equimolar aqueous mixture of all three metal ions. The influence of pH value and initial concentration of the solutions and interaction of the selected ions and their impact on the adsorption have been studied. Experimental adsorption data were analyzed with the Langmuir and Freundlich isotherm model. The experiments showed promising results. In solutions with single metal ion removal percent obtained by bentonite were 98.1% for lead, 99.81% for copper, and 98.16% for iron. By using zeolite removal percent was 99.53% for lead, 98.47% for copper, and 96.11% for iron, while by using steel slag it was 99.98% for iron, 99.96% for copper, and 85.92% for lead. By examining the trinary solution, it could be seen that higher initial concentrations promote adsorption of lead and iron on zeolite and bentonite in the presence of other ions. When using steel slag removal percent of lead was noticeably higher in the trinary solution.

KEYWORDS:

• Adsorption
• zeolite
• bentonite
• steel slag