Investigating Methylene Blue Removal from Aqueous Solution by Cysteine-Functionalized Mesoporous Silica

Figure 9

Adsorption isotherms fitted to the adsorption equilibrium data: (a–c) the Langmuir model at pH 1.5, 7, and 8.5, respectively; (d–f) the Freundlich model at pH 1.5, 7, and 8.5, respectively; (g–i) the Temkin model at pH 1.5, 7, and 8.5, respectively (150 ppm, 25°C, and 150 rpm).

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)