Application of bio-synthesized silicon nanoparticles from bamboo stem for the remediation of heavy metals in contaminated water

Silicon nanoparticles (SiONPs) were successfully synthesized from bamboo stem for the remediation of Pb (II), Cr (VI) and Cd (II) ions in contaminated water, the synthesized SiONPs was found to be an excellent adsorbent for Pb (II) ions as compared to Cr (VI) and Cd (II) ions. The investigation to determine the adsorption efficiency of SiONPs from bamboo stem for the removal of Pb (II), Cr (VI) and Cd (II) ions was carried out using batch process in aqueous solution. The after-adsorption characterization of the SiONPs through FTIR, XRD, UV-VIS and XRF indicated strong evidence of interaction that can be attributed to the binding of the heavy metal’s ions to the surface of the adsorbent. The adsorption of these metal ions from aqueous solution is consistent with the mechanism of physical adsorption; it is time independent, concentration and adsorbent dose dependent. Its adsorption characteristics best fitted the Freundlich, Temkin and Dubinin-Radushkevich adsorption models. From the Freundlich and Temkin models, the extent of interaction was established through the values of their respective adsorption constant. Also, the adsorption kinetic of the adsorbates agrees excellently with the pseudo first and second order kinetic models.