Application of erionite as an adsorbent for Cd2+, Cu2+, and Pb2+ ions in water

Erionite was synthesized by the hydrothermal method using NaOH, KOH, tetramethylammonium chloride, and silica sol. The synthesized erionite was characterized for materials crystal/amorphous properties, surface morphology, functional groups, and surface area measurements. The synthesized and characterized composite material was used for the scavenging of the Cd2+, Cu2+, and Pb2+ ions in the aqueous medium. The scavenging behavior of erionite towards Cd2+, Cu2+, and Pb2+ ions was evaluated in a batch adsorption process. The process variables, such as initial metal ions concentration (10(-8) to 10(-5) mol/L), solution pH (2-10), and temperature (30 degrees C-50 degrees C) were varied within the selected range to observe the effect of each variable. The best fitting of the adsorption isotherm data in the isotherm (Langmuir and Freundlich isotherm) models were decided according to correlation coefficient (R-2), root mean square error (RMSE), and standard deviation (SD) values. According to Langmuir, the highest uptakes for Cd2+, Cu2+, and Pb2+ metal ions at 50 degrees C were 258.71, 265.41, and 275.73 mg/g, respectively. The maximum sorption of Cd2+, Cu2+, and Pb2+ on synthesized erionite was achieved in the pH range 6.0-8.0. Sorption of metal ions was found to be enhanced with the rise of adsorbent dosage. Sorption isotherm data were followed Freundlich model according to R-2, RMSE, and SD values.