Adsorbents Langmuir parameters R2 b (L/mg) Qmax, fitted Qexp RL OPC 0.998 0.13 434.78 409.25 0.012 OSC 0.999 1.92 354.61 359.04 0.008 PC 0.996 0.25 327.87 326.19 0.007 SC 0.997 0.65 35.36 34.82 0.015 Table 1: Parameters of Langmuir isotherm for adsorption of MB by SC, PC, OSC and OPS.