Kinetics and equilibrium studies from the methylene blue adsorption on diatomite treated with sodium hydroxide

摘要: Abstract Diatomite was treated with sodium hydroxide to remove impurity in order improve its performance as an adsorbent. The raw diatomite and purified were characterized by scanning electron microscopy, energy dispersive X-ray analysis Brunauer–Emmett–Teller adsorption. It found that the surface area of 15.87 m2 g− 1 for 31.35 m2 g− 1 diatomite. Scanning microscopy images showed well-developed porous structure Purified improved a more than tenfold increase adsorption amount from 1.72 mg g− 1 18.15 mg g− 1 removal efficiency 8.60% 90.75% methyelen blue initial concentration 100 ppm respectively. kinetics studies experiment data followed pseudo-second-order model better. equilibrium fitted Langmuir Freundlich isotherms presented best fit, showing maximum monolayer capacity 27.86 mg g− 1. thermodynamic parameters such standard enthalpy, entropy free evaluated. obtained results indicated methylene onto is endothermic spontaneous process confirmed applicability this inorganic material efficient adsorbent basic dyes.