Mechanism and behavior of surfactant adsorption onto resins with different matrices

The recovery of surfactant from wastewater utilizing polymeric adsorbent is important not only in the protection of the environment from pollution, but also in the effective use of raw materials. Mechanism and behavior of surfactant (linear dodecyl-benzene sulfonate, LAS) adsorption onto styrene resin XAD-4 and acrylic ester resin was studied in high concentration solution (several thousand mg/L). For comparison, a series of acrylic ester resins had been prepared, characterized and used along with commercial resins XAD-7 and HP2MG. Y-50 resin, one of the resins, exhibits better adsorption capacity than the other acrylic ester resins in this study. The experimental equilibrium data were fitted to Langmuir model, and the model was found to provide very good fits for all of acrylic ester resins over the temperature range, whereas fitted results for the styrene resin XAD-4 were less accurate. Adsorption kinetics and elution processes were also investigated to study different mechanism and behavior of surfactant adsorption onto resins. The observation indicates that the cooperation of hydrophobic interactions and electrostatic attraction impels the adsorption process as well as the formation of monolayer and bi-layer.