South African Journal of Chemical Engineering (Jan 2021)
Chemical removal of cobalt and lithium in contaminated soils using promoted white eggshells with different catalysts
Abstract
The use of raw white eggshells (WES) as a catalyst, and promoted WES with acetic acid as a promoted catalyst for study the adsorption of cobalt (CO+2) and lithium (Li+) ions from polluted soils was investigated in this paper. The selection of a treated chemical substance was achieved after performing several experiments under controlled laboratory conditions using three chemical substances covering different range of pH: acidity (acetic acid), neutral (potassium iodide), and alkalinity (baking soda) media to determine the optimal conditions for improving CO+2 and Li+ recovery from soil contaminated samples. Several operating factors were examined in order to detect their corresponding effects on the catalyst behavior. These factors were: pH, incubation time, the initial concentration of CO+2 and Li+ ions, the dose of the WES, and the ambient temperature. The maximum adsorption efficiency of CO+2 and Li+ions were 94 and 85% for promoted WES at the incubation time of 21 and 7 days, pH of 5 and 4, temperature of 50 and 45 °C, and WES dose of 2.5 and 3 g, respectively. A regression equation was developed to investigate the removable percentage for both pollutants at different dosage of ordinary WES. This method introduces an innovative idea for promoting the process of remediation of light and heavy metals using a low-cost adsorbent under controlled laboratory conditions.