Adsorption of aqueous alkylphenol ethoxylate surfactants by mesoporous carbon CMK-3

Mesoporous carbon, CMK-3, was prepared using hexagonal SBA-15 mesoporous silica as the template and the adsorption of nonylphenol ethoxylates (NPE) onto CMK-3 was investigated. The adsorption process was well described using pseudo-second-order kinetics. At initial NPE concentrations of 107 and 530 mg l−1, the adsorption rate constants were found to be 5.6×10−35.6×10−3 and 8.7×10−4 gmg−1min−1, indicating that a higher initial concentration or adsorption amount resulted in a lower adsorption rate. NPE adsorption onto CMK-3 fitted a Langmuir–Freundlich model and the maximum amounts of NPE absorbed at 15, 25, and 35 °C were 923, 720, and 463 mg g−1, suggesting an elevated adsorption capacity of CMK-3 for NPE with decreased adsorption temperature. In addition, increasing adsorption temperature led to the change of the adsorption model from the Langmuir–Freundlich to the Langmuir model. N2 adsorption results showed that the adsorption of NPE led to a decrease in the mesopore volume of CMK-3. However, the pore width of NPE-loaded CMK-3 was found to be identical to that of CMK-3.

Mesoporous carbon CMK-3 with ordered mesoporous structure and narrow pore size distribution was used to adsorb aqueous NPE.Figure optionsDownload as PowerPoint slide