Comparative Study of Zinc Metal Removal using Crude and Modified Spirulina Microalgae by Magnetic Nano Adsorbent

In this research, adsorption of Zinc ion was investigated at batch system using spirulina microalgae and Magnetic microalgae. The effect of important parameters such as pH of the solution, absorbent contact time, the initial concentration of Zn(II) ion, adsorbent dosage and temperature were investigated on The removal efficiency and  adsorption capacity. Also adsorbent features were studied by using SEM photographs and FT-IR spectroscopy. The maximum Zinc ion adsorption occurred in pH=6. The optimum adsorbent dosages were determined 0.03 g for spirulina microalgae and Magnetic microalgae. So at optimum pH and adsorbents dosage for 150 mg/l initial zinc ion concentration 84.43% and 96.56% of removal efficiency was obtained for spirulina microalgae and Magnetic microalgae, respectively. Removal efficiency increased by increasing contact time between adsorbent and solution and after passing 10 min for spirulina microalgae and Magnetic microalgae reached to equilibrium. Examining kinetic models showed that pseudo-second order kinetic model had best fit for adsorbents. In investigating Zinc ion initial concentration in range of 50-300 mg/l, results showed by increasing initial concentration, efficiency decreased. Also experimental data of spirulina microalgae and Magnetic microalgae solutions had best fit by sips and Langmuir, respectively. Investigating temperature effect showed, by increasing temperature, removal efficiency decreased for spirulina microalgae and Magnetic microalgae. The thermodynamic parameter was studied in 298, 303, 313 and 323 Kelvin.