Simultaneous Removal of Pb2+ and Cu2+ by SBA-15/di-Urea as a Nano Adsorbent

In this study, the potential of SBA-15/di-urea nanoporous silica compound for the removal of Pb2+ and Cu2+ ions was investigated. The presence of organic groups in the silica framework of SBA-15/di-urea was demonstrated by the FT-IR spectrum. The functionalized product showed the BET surface area 518 m2/g and pore diameter 6.5 nm, based on adsorption-desorption of N2 at 77 K. SEM revealed a rod-shaped morphology, and the TEM image showed an ordered array of 2D hexagonal mesoporous SBA-15. The ions in the samples were identified by flame atomic absorption spectrometry. The effect of adsorbent amount, contact time, metal concentration, pH, and presence of other metals on removal efficiency has been studied. Simultaneous removal of Pb2+ and Cu2+ ions from 20 mL of the sample solution containing 60 μg of each ion were completely done at pH greater than 5.0 after stirring for 15 minutes. Langmuir, Freundlich, and Temkin adsorption isotherms were evaluated for both adsorbates and it was determined that the data fitted well with the Langmuir model (R2> 0.98). The maximum capacity of the adsorbent was found to be 147.0 ± 0.6 mg and 77.0 ± 0.5 mg of Pb2+ and Cu2+ ions/g SBA-15/di-urea, respectively. The lowest amount of 3M nitric acid for stripping the target species from adsorbent was determined as 20 mL. The application of this methodology for the real sample was tested by an Industrial wastewater sample.