Abstract

The present study reports the synthesis of ZnS nanoparticles via green synthesis route and loading them onto the jamun seeds biochar to prepare a nanocomposite. The synthesized nanocomposite were characterized with FTIR, XRD and SEM. The synthesized ZnS nanoparticles were found to be spherical in shape with size less than 5 nm. SEM images confirmed the loading of ZnS nanoparticles onto the biochar. The nanocomposite was employed in the removal of Pb²⁺ ions using a developed CCD by RSM. The significance of the model was supported by the p-value being less than 0.0001 and higher F-value. The loading capacity of the ZnS loaded biochar is calculated to be 211.0 mg g^-1. The isotherm and kinetic investigations suggest the applicability of Langmuir and Pseudo second order models to the equilibrium data. The spontaneity of the process is well supported by the thermodynamic values. 0.1 M HCl exhibited highest desorption ability compared to other desorbing agents and successfully regenerated the nanocomposite. The ability of the ZnS loaded biochar nanocomposite to successfully eliminate the Pb²⁺ ions was demonstrated and unveils the real time applications in waste water treatments.