Removal of Zn(II) ion from aqueous solutions by jellan gam-chitosan complex bioadsorbent

Zinc is widely used in many important industrial applications such as dry cell, electroplating industry, insecticides, foundry, metallurgy, pigments and explosive manufacturing. Zinc is often found in high concentrations in wastewater from many sources, including mine drainage, galvanizing plants, pharmaceutical production and pigment production. Conventional technologies used to remove Zn(II) from wastewater include chemical precipitation, membrane separation, electrolysis, ion exchange and adsorption. Among these technologies, the adsorption method is preferred because it is cheap, effective and easy to apply. In the presented study, cross-linked gellan gum particles (GG) were kept in chitosan (CS) solution and after polyelectrolyte complex formation took place, the particles were removed from the solution, purified and then cross-linked. The potential of these prepared particles in removing Zn(II) ions from wastewater was investigated. FT-IR, BET and SEM/EDX analyzes were performed for the characterization of the obtained polyelectrolyte complex. In the adsorption studies performed with the polyelectrolyte complex, the optimum pH value was determined as 6. When the experimental conditions were applied at temperature: 25°C, pH: 6, the initial concentration of the solution: 200 ppm, and the adsorption time: 10 hours, the adsorption capacity was found to be approximately 42.05 mg/g. Kinetic studies have shown that the experimental results are consistent with the pseudo-second-order kinetic model. The Langmuir isotherm model was also found to be compatible with the equilibrium adsorption results. It has also been determined that the complex adsorbent can be used at least five times without a serious decrease in the adsorption capacity.