Zeolite modified with copper oxide and iron oxide for lead and arsenic adsorption from aqueous solutions

How to completely remove toxic metals from water is still a serious challenge, and is the mission that faces researchers and scientists today. In this work, zeolite/copper oxide (CuO) and zeolite/iron oxide (Fe₃O₄) nanocomposites (NCs) were prepared via a co-precipitation method. Several techniques were used for characterization of the prepared NCs including UV-visible, powder X-ray diffraction, N₂ adsorption for determining the specific surface areas (Brunauer–Emmett–Teller (BET)) and pore volumes. The morphology was investigated by field emission scanning electron microscopy. The batch adsorption experiment process was used to study the applicability of the prepared NCs to removing lead (Pb) and arsenic (As) from aqueous solutions. The effects of the adsorbent dosage, pH, initial metal concentration and contact time on the adsorption process were investigated. The obtained results revealed that in 40 minutes 0.15 g of prepared zeolite/Fe₃O₄ (NCs) was able to remove 97.2% of Pb and 96.8% of As from 100 mg/L aqua solutions at a pH of between 4 and 6. The Langmuir isotherm model showed higher correlation coefficients and provided better agreement with the experimental data. The adsorption kinetic is a chemi-physisorption process that follows the pseudo second-order kinetic model.