Effect of Extending Contact Time on Efficiency of Fava Beans Pods as Bioadsorbents to Remove Lead Ions from Aquatic Solutions

Abstract

Abstract: Pollution of aquatic systems with toxic heavy metals is concernedly increased worldwide. Danger of these metals lies in their ability to bioaccumulate in human and living organisms through food chains. They can cause a wide range of diseases and disorders. Removal of heavy metals from contaminated media and cleaning the ecosystems require introducing effective and eco-friendly approaches which represents a challenge in itself. Phytoadsorption process, which is one of the bioremediation techniques, is a green, simple, inexpensive, and sustainable approach used for cleaning the aquatic systems from heavy metals. However, aim of this work is to utilize various loads of dry, empty fava beans pods particles (size: 350-1000 μm) as a bioadsorbent to remove Pb2+ from aqueous media at room temperature without making any change on pH of media. In all experiments, this biomaterial was able to remove up to 59.6% of lead ions with an adsorption capacity up to 59.6 mg/g after 120 minutes of shaking. Moreover, the phytoadsorbent showed significant efficiency compared to previous studies that used contact shaking times of 30, 60, and 90 minutes.