Mousa Mohammadpour - Department of Water Science and Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
Hossein Babazadeh - Department of Water Science and Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
Ali Afrous - Department of Water Engineering, Dezful Branch, Islamic Azad University, Dezful, Iran
Ebrahim Pazira - Department of Soil Science, Science and Research Branch, Islamic Azad University, Tehran, Iran

Heavy metals are generally found in industrial wastewaters, affecting human health and living organisms. This study was therefore aimed to use bioadsorbents rice husk and activated carbon-silica to efficiently remove the heavy metals including lead (Pb) and cadmium (Cd) from an aqueous wastewater. The effects of bioadsorbent content, initial concentration, contact time, and pH value on the metal removal were investigated. An increased metal initial concentration lowered the removal efficiency of the bioadsorbents, and pH ۶ provided the best condition for the removal of Pb and Cd. The use of rice husk and activated carbon-silica at pH ۶ resulted in a maximum metal removal of ۸۱% and ۹۸% for Pb, while ۸۸% and ۱۰۰% for Cd respectively. The adsorption parameters were then determined by the Langmuir and Freundlich adsorption isotherms, and the experimental data were better fitted in the Freundlich adsorption isotherm model in comparison with the Langmuir adsorption isotherm model.

Bio-adsorbent, cadmium, Freundlich, Langmuir, lead