Selective Removal of Lead (II) Ions from Wastewater with Fabricated ZnO-PVA Membrane

Water contamination is a serious threat to living organisms and the contamination is increasing day by day due to versatile applications of heavy metal ions. Various types of materials have been reported for removal of these heavy metal ions from water but selection of heavy metal ions from wastewater is still a serious issue. In this regard, a ZnO-PVA-coated membrane was designed for the selective removal of Pb+2 ions from wastewater. The procedure known as sol-gel was adopted in order to produce ZnO nanoparticles by using the extract of bio-inspired Azadirachta indica (neem) leaves. Then, ZnO-PVA was synthesized for coating the membrane by a simple solution-casting process. The system was characterized by XRD, FTIR, FESEM, EDX, and XPS. The ZnO-PVA-coated membrane was applied for the extraction of toxic metal ions present in polluted water. The coated membrane selectively removed the Pb+2 ions from the contaminated water solution. The removal efficiency of the ZnO-PVA-coated membrane for Pb+2 ions was found to be 93.99% at pH = 4. The kinetic study and adsorption isotherm indicated that the monolayer membrane well-chemisorbed Pb+2 ions. The highest possible Pb+2 ions adsorption capacity calculated by the adsorption isotherm was found to be 218.47 mg/g.

Automated summary

Water contamination is an increasing problem due to the versatile applications of heavy metal ions, but the selective removal of these ions from wastewater remains an issue. To address this, a ZnO-PVA-coated membrane was developed using a sol-gel process and bio-inspired Azadirachta indica (neem) extract. The membrane successfully removed Pb+2 ions from polluted water solution, with a removal efficiency of 93.99% at pH=4 and a maximum adsorption capacity of 218.47 mg/g.