Synthesis, Characterization, and Application of TiO2/MMT for Removal of Pb2+ from Industrial Wastewater

The release of heavy metals into the environment due to industrialization and urbanization has caused major problems throughout the world. Increasing the pollution of the environment by heavy metals due to carcinogenicity and biological accumulation has caused serious concerns. Therefore, the adsorption of heavy metals from industrial wastewater is one of the important environmental issues. Lead is one of the four metals that have the most effect on human health. So far, different methods have been considered for adsorbing lead. The use of biocompatible adsorbents is one of these methods. Montmorillonite (MMT), a clay mineral with unique physical and chemical properties are considered a biocompatible adsorbent. In this study, after modification of the surface of the MMT by titanium dioxide was characterized by FT-IR, XRD, FE-SEM, and BET techniques. Then the activity of the MMT nano-adsorption immobilized on the surface of titanium dioxide (TiO2/MMT) was investigated for the removal of lead (II) ion and different factors such as contact time, adsorbent dosage, lead (II) ion concentration, and pH were optimized. The efficiency of this nano-adsorbent is such that even in the presence 10 mg can eliminate a significant amount of lead ion (II) (50 ppm) with a yield of about 90% at neutral pH over a short period of time (5 minutes). Moreover, the experimental results showed that the adsorption capacity of Pb2+ ion by TiO2/MMT decreased by only about 8-10 % after performing 12 runs of the adsorption process.