Optimization of Adsorption Process of Cr (VI) from Aqueous Solution Using Biosynthesized Palladium Nanoparticles by Spirulina Platensis

Aims: Chromium has destructive effects on the environment and various chemical methods have been investigated for removal of Cr (VI), but high cost and environmental problems have led to using biological methods to remove chromium. The aim of this study was to optimize adsorption process of Cr from aqueous solution, using biosynthesized palladium nanoparticles by Spirulina Platensis. In this experimental study, palladium nanoparticles were synthesized, using Spirulina Platensis and examined by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) methods. During the process of adsorption of chromium, pH, contact time, initial Cr concentration, and adsorbent dosage to optimization were optimized. Adsorption isotherms for Chromium were also determined on palladium nanoparticles based on Langmuir and Freundlich isotherm models. Findings: The extract of Spirulina Platensis had the ability to synthesize palladium nanoparticles. The maximum removal was obtained at pH=2, initial chromium concentration=0.1mg/l, contact time=20 minutes, and adsorbent dosage=0.5g/l, and the removal percentage varied from 68.9% to 98.1%. RL for palladium nanoparticles was in the range of 0.17 to 0.95, showing that Langmuir model was suitable for adsorbent. Biosynthesized palladium nanoparticles by Spirulina Platensis high efficiency in removing chromium in aqueous solutions.