Fabrication of ph sensitive hydrogels for removal of biohazard metal ions and their counter parts

Abstract

Heavy metals are quintessential to maintain various biochemical and physiological functions in living organisms when present in very low concentration; however, they become noxious when they exceed certain threshold concentrations. A number of methods including coagulation and precipitation, ion exchange treatment, membrane filtration, and electrochemical technique have been developed for early detection and removal of toxic heavy metals from environments. But limited success has been achieved to date due to their less efficiency and, further generation of toxic sludge or other waste products and, high cost ly and more time consumingption. Recently polymeric hydrogel based system have been attracted special attention for effective removal of heavy metals because of functional groups on polymer chains enable to readily adsorb and diffuse heavy metals from wastewater and release these metal ions from the hydrogels upon changes in aqueous environment. An ionogenic polymer hydrogels wasare prepared by copolymerization of a neutral monomer with an ionic co-monomer in presence of a suitable initiator and a cross-linker. Different types of ionic co-monomers such as strongly acidic or basic, weakly acidic or basic and zwitterionic with varying monomer to co-monomer ratio are used to fabricate the hydrogels. and their The heavy metals removal and cationic and/ anionic dyes removal capacity via electrostatic interactions and porous structure of hydrogels are envisaged. Removal efficiency was studied and established by UV-vVisible spectroscopy and cyclic voltammetry. Hydrogel containing more anionic functional groups showsed more removal efficiency of heavy metals and dyes by electrostatics force and porosity if polymer network. HydrogelsThe release and recover theseof dyes and metals metals from hydrogel at pH 1 aqueaous solution are observed. The mMechanical strength of hydrogels alsois increased due towith incorporation of heavy metals via the formation of additional crosslinkings with anionic functional groupsmoieties of polymer chainsnetwork with metals ion via electrostatics interactions.