การศึกษาจลนพลศาสตร์และเทอร์โมไดนามิกส์ของการดูดซับไอออนโลหะหนักโดยเปลือกเมล็ดทานตะวัน

Abstract

A study of the factors effecting the adsorption of Lead(II) Zinc(II) and Nickel(II) ions by modified sunflower seed husk was investigated in batch absorption in order to obtain the optimum conditions for heavy metal adsorption process. In this study, the factor are carbonized temperature (400 to 600°C) contact time, adsorbent size (less than 80 to more than 170 mesh), pH of solution (2 to 6) and solution temperature (30 to 50°C). The maximum adsorption capacity of lead(II) and zinc(II) ions occurred 400°C modified husk with 99.332 and 99.033 percent respectively . Whereas that of nickel(II) ions, occurred 500°C modified husk with 98.915 percent. For maximum adsorption occurred in size 120 to 170 mesh. In part of pH value, for maximum adsorption of heavy metal ions occurred in pH 5 and zinc(II) ions occurred in pH 4. Increasing the solution temperature from 30 to 50°C appeared to have no effect on the heavy metal ion removal from solution. The kinetic adsorption conformed to pseudo-second order. Thermodynamic adsorption of lead(II) zinc(II) and nickel(II) ions are consists of negative enthalpy. Furthermore, Gibbs free energy increased with negative trend in temperature solution range of 30 to 50 °C. The adsorption process conformed to the Langmuir Adsorption Isotherm with the maximum adsorption of lead(II) zinc(II) and nickel(ll) ions were 26.316, 26.110 and 22.727 mg/g with KL of lead(Il) zinc(II) and nickel(ll) ions were 0.038, 0.038 and 0.023 L/mg respectively.