Heavy metals biosorption efficacy of Azolla filiculoides and Hydrilla verticillata

Abstract

Due to advancement in science and technologies, industrialization as well as newlineurbanization has opened new vistas to exploit the inherent traits of natural resources. newlineTo surmount the damage inflected to environment (natural aquatic and terrestrial newlineecosystems), worldwide attention is being focused upon the mitigation of metallic newlinepollution in environmental restoration areas over conventional methods. Biosorption newlinehas been enormously considered an alternative metal removing method, based on newlinemetal-sequestering properties of certain natural materials of biological origin newlineIn the present study, a comparative evaluation of heavy metal removal efficacy from newlinefloating and submerged macrophytes was performed. Azolla filiculoides (free floating) newlineand Hydrilla verticillata (submerged) aquatic macrophytes were utilized for arsenic, newlinecopper, chromium and lead removal from the respective metallic ion solutions. Batch newlineexperiments were performed initially with optimization of different physical newlineparameters viz., pH, initial heavy metal concentration, biosorbent dosage, contact newlinetime, temperature and agitation speed. Submerged (Hydrilla verticillata) had depicted newlinebetter removal efficiency in comparison to the floating macrophyte (Azolla newlinefiliculoides). Field emission scanning electron microscopy equipped with energy newlinedispersive spectroscopy and Fourier transform infrared spectroscopy analysis was newlineperformed for the characterization of the metal loaded biosorbents. Biosorption of the newlinerespective heavy metal was clearly depicted in the FESEM-EDX spectrum, although newlinenot much change in the morphology of the biosorbents were examined. FTIR spectra newlineof the biosorbents obtained after the experiments confirmed the involvement of C H newlinebend, CH 2 (C=O), N H, C O, R 2 C= bending and C C=O on the biomass. newlineFurthermore, the biosorbent regeneration followed by heavy metal biosorption newlineconfirmed the reusability of the prepared biosorbent for at least two consecutive newlinecycles without much significant change in the heavy metal biosorption capacity. newlineFurther