Impact of Irradiated or Non-Irradiated Nanomaterials on Decontamination of Pb and Cd in Wastewater

Chemically synthesized nano zeolite and nano-rice char were prepared to be used as adsorbents for Pb and Cd from the artificially contaminated water. Properties and elemental configuration of nanoparticles were identified. X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) were utilized to identify the functional groups accountable for the sorption of the concerned contaminants by the nanoparticles.  The hydroxyl group was identified as the peak detected in the FT-IR analysis of nano zeolite, whereas the bands of rice straw char were attributed to several broad peak functional groups, including hydroxyl groups and others. These nanoparticles' activities were investigated at various values of the nano sorbent mass and temperature. Increasing the nano sorbent mass from 0.25 to 0.75 g, a significant improvement in removal efficiency of the elements under study. however, beyond, 0.75 g of the nano biosorbent mass did not significantly alter the sorption process. Given that a temperature rise improves the interaction between the sorbent and the metal ions, the findings revealed that the high mobility of metal ions may also be responsible for the increase in metal ions sorption by the Nano sorbent. Furthermore, in comparison with the non-irradiated sorbents, the irradiated ones showed a decreased capability for removing Pb and Cd. The correlation coefficient (R2) values for both Pb (II) and Cd (II) ions indicate that Langmuir's model succeeded in description of sorption of both Pb indicating that adsorption is the main process responsible for Pb and Cd sorption by the nano sorbents under study. The maximum adsorption capacity (qmax) values for Pb (II) and Cd (II) ions were determined to be 4.09 mg/g and 7.18 mg/g, respectively, based on the Langmuir model. These findings indicated that, because of the habitation of active sites, the values of the constant K2 for the biosorbent materials exposed to gamma radiation were greater than the corresponding ones of the nonirradiated nano sorbent materials.