Evaluation of Bioadsorption Process of Lead Heavy Metal from Aqueous Media Using Two Species of brown Nizimuddinia zanardini algae and Ulva rigida Green Algae

In this research, the biological adsorption process of lead heavy metal was investigated using brown algae Nizimuddinia zanardini and green algae Ulva rigida. Optimum adsorption conditions by measuring pH, the amount of adsorbent, time, and the concentration of lead ion were investigated. Langmuir, Freundlich, and Temkin isotherms were used to investigate surface adsorption. Adsorption kinetics were investigated according to pseudo-first and second-order kinetic equations. Examining the pH results, it was found that brown algae at pH = 5 and green algae at pH = 6 could reach the maximum adsorption of lead. Examining the time-related results, it was found that the best adsorption time for both algae was 60 min. The results of the adsorbent dosage showed that the two bioadsorbents of brown and green algae have the highest amount of adsorption in the amounts of 0.5 and 0.7 g, respectively, and in the initial concentration of metal ions, the highest efficiency was obtained in the dosage of 2 mg/l. The results of the isotherm model showed that lead adsorption by brown algae corresponds to the Langmuir isotherm and green algae to the Freundlich isotherm. Also, according to the kinetic results, both adsorptions follow second-order kinetics.