A polymer – zeolite composite for mixed metal removal from aqueous solution

Heavy metals become inevitable pollutants that are toxic to life. Lots of treatment methods are available; adsorption is a cheap option. Metals are mostly found as mixtures in wastewaters. Taking this into account, a natural composite adsorbent aims to remove multiple heavy metals (Pb 2+ , Cu 2+ , Cd 2+ ). Alginate was combined with clinoptilolite to form alginate - clinoptilolite (A-C) beads. First, factors influencing the removal efficiency of metals were investigated. Then, continuous column experiments were performed to evaluate the real application potential of the adsorbent. A-C beads preferably adsorbed Pb 2+ . Batch experiments showed metal uptake reached equilibrium after 24 hours and kinetics were compatible with the first-order. Also, pH values near neutral levels were observed to increase heavy metal removal. On the other hand, adsorption equilibrium was well described by the Langmuir model for Cu 2+ and Cd 2+ and by the Freundlich model for Pb 2+ . The highest heavy metal uptake was calculated as 2,145 mg /g A-C beads for Pb 2+ . Continuous column operations were suggested to apply low flow rates (<2 mL/min) and heavy metal concentration (<10 mg/L) for effectiveness. A-C beads can be a good candidate for mixed heavy metal removal composed of environmentally friendly and low-cost materials.