Kinetika Adsorpsi Zat Warna Direct Brown Menggunakan Hidroksiapatit Dengan Variasi Dosis Adsorben dan pH Larutan

Adsorption is a dye absorption process using various adsorbents. Dye waste produced by industry can pollute the environment because it is dangerous and poisonous. In this study, calcium-deficient hydroxyapatite with a Ca / P ratio of more / less than 1.67 was used as the adsorption medium. Utilization of the adsorption process in dye absorption is useful for determining isotherm models and adsorption kinetics. The dye used is direct brown. The dye adsorption process was carried out at variations in pH (6, 7, 8) and adsorbent mass (0.1; 0.15; 0.2 wt%) at a rotating speed of 250 rpm and 30 ppm of dye concentration. The maximum adsorption capacity occurs at pH 6 with an absorption efficiency of 51.4%. The equilibrium model tested is the Langmuir, Freundlich, Harkins Jura, Temkin equilibrium model. and Dubinin-Raduskevich. The isotherm model of the direct brown dye adsorption process follows the Temkin model with a R2 value of 0.9996. The adsorption kinetics tested were Pseudo First Order, Pseudo Second Order, Elovich and Intraparticle Diffusion. The kinetics of the direct brown dye adsorption process followed the intraparticle diffusion order kinetics model with R2 value of 0.9938 in the adsorption process with a pH of 6 and an adsorbent mass of 0.5 grams.