SYNTHESIS AND CHARACTERIZATION OF MAGNETIC4d-TRANSITION METALION-IMPRINTEDKAOL IN CHITOSANHYBRID FOR SELECTIYEMITIGATION OF METALTOXICITY INPLANT

Abstract

ABSTRACT The contamination of soil by toxic metals is a critical environmental challenge which poses a significant risk to the ecosystem and human health. Several soil remediation methodshavebeenexploredbuthavebeenlimitedbypoorselectivity,highproduction cost and reusability. This work explored the adsorption capability of chitosanandkaolin indevelopingasustainable,selective,andreusablesolutionforcadmiumdetoxification insoilusingabio-based hybrid material.Itsuccessfully synthesizedandcharacterized palladium(pd),Silver(Ag)andcadmium(Cd)ion-imprinted polymers(IIPs)andnon-imprinted(NIP)fromMagnetickaolin-chitosannanocomposite(MKCNC)andstudied theiradsorption potentials. IIPsandNIPwerecharacterized usingUltra-violet/Visible spectroscopy (UV-vis), Fourier Transform Infra-red spectroscopy (FTIR), Scanning Electron Microscopy coupled with Energy Dispersive X-ray Analysis (SEM-EDX), ThermogravimetricAnalysis (TGA)andInductivelyCoupled Plasma-OpticalEmission Spectroscopy(ICP-OES).TheadsorptionpotentialofthesynthesizedIIPsandNIPwere investigated on maize plantings. Maize seeds were planted in soil spiked and treated withwateronly(pot1),25mgCdIP(pot2),25mgCdIP20mgCdC12(Ot3),50mg CdIP+20mgCdCl2Ot4)and25mgNIP+20mgCdC12Ot5).TheUV-visabsorption bands of the leached and unbleached IIPs showed sharp band at around 224-240 rim indicatingz—+z*transition.TheFTIRresultofthenanocompositeshowedthec(C—N)str (imine/azomethine)functional groupat1615cm1,however upon polymerization,the three IIPsshoweda highervibrational frequency (blue shift) at the region of u(C=N)strat1628cm‘'(PdlP),1638 cm‘'(AgIP) and1636 cm”'(CdlP). The SEM-EOXshowedcrystallinemorphologyoflargeirregularparticles.ThesurfacesoftheIIPs appearedto be coveredwith powderedmaterials.TGAoftheNIPand IIPsshowed 4stages of weight loss. There was no obvious difference between the absorbance bands of leached and unbleached IIPs. This is an indication that the polymermatrixremainsun altered even after leaching. The powdery surfaces of the SEM-EDX images could be at tribute to the imprinting of ions on the surface of the IIPs. The thermal studies showed that CdIP demonstratedthegreatestthermalstabilityamongstthethreeIIPs.Optimalreactionconditionof 89% adsorptionwas observedat pH 6.5 atareactiontimeof90 minutes.The NIP andCdIP showed excellent adsorption capacity by successfullymitigating Cd ions from being translocatedinto the maizeplantbody.Thenon-imprintedandion-imprintedpolymershavethepotentialof contributing to the advancement of sustainable soil remediation technologies and supportagricultural productivity andenvironmentalhealth.