Biosorption Study of Ni(II) on Apple Peel Granola from Aqueous Solution

Introduction: Nickel is found in various industrial processes such as electroplating, leather tanning, cement preservations, paints and pigments, textile, steel fabrication and canning industries. It has been proven that Ni(II) has several health hazards and is carcinogenic. The aim of this study is to evaluate Ni(II) adsorption on apple peel granola from aqueous solution. Material and Methods: This study was done in the laboratory scale and batch condition. In this study, the effects of adsorbent dose, contact time and pH were investigated on the removal of nickel by batch process. The apple peels granola was prepared in lab conditions, and sieved by standard sieves of 60-100 mesh. The nickel concentration in standard and unknown samples was measured by AA spectrophotometer. To understand the adsorption process, the experimental data were analyzed with some isotherm and kinetic models. Results: The maximum removal was found at pH= 7. The nickel removal efficiency decreased from 50.1 to 25% by increasing adsorbent dosage. By increasing the pH from 3 to 7, the removal efficiency increased from 19.8% to 35.0% at 30 min contact time. The adsorption isotherm and Kinetic analysis of our results showed that the results were compatible with Freundlich isotherm model (R2= 0.909) and pseudo-first-order kinetic model (R2= 0.926). Conclusion: The results showed that apple peel granola was able to absorb nickel from aqueous solutions and removal efficiency was more in pH=7. Preparing apple peel granola adsorbent is simple, cheap, and superior in application because of its porous structure in comparison with other natural adsorbents.