Current World Environment

The present article describes the adsorption behavior of some low cost adsorbents such as olive waste, maize cobs, bentonitic clay, wheat bran, coal ash and coffee waste, with respect to Pb²⁺, Cu²⁺ and Zn²⁺ ions. The batch method was used and parameters such as electrical conductivity, pH, contact time, adsorbent dosage and initial and final concentration of metal ions were studied. All used adsorbents were effective, but coal ash was most effective, with total removal for all ions of over 90%, with highest percentage removal from 99.2% for Zn²⁺ ions and 97.5% of Pb²⁺. Maize cob was an effective adsorbent with maximal percentage removal of 92.6% for Zn²⁺ ions, wheat bran had highest removal of 93.7% for Pb²⁺ ions as did olive waste, 97% for Pb²⁺ ions. Coffe waste offers considerable promise as a low-cost natural adsorbent with highest efficiency in removal of Pb²⁺ with 97.5% while bentonitic clay having a structure with net negative charge, which is neutralized by positively charged species, resulted also as an effective low cost adsorbent with max total removal from 92.7% for  Pb²⁺ to 80.9% for Zn²⁺ ions.