Solubilization and adsorption behaviors of 2,4,6-trichlorophenol in the presence of surfactants

• The solubility of 2,4,6-trichlorophenol was enhanced 72 times by sodium deoxycholateat pH 7.5.
• NaDC demonstrated the best solubilization potential, followed by NaC, SDS and β-CD.
• The adsorption of 2,4,6-trichlorophenol was almost zero when NaC concentration was above CMC2.

The solubilization of 2,4,6-trichlorophenol (2,4,6-TCP) was studied in the presence of four different surfactants, namely sodium deoxycholate (NaDC), sodium cholate (NaC), sodium lauryl sulfate (SDS) and β-cyclodextrin (β-CD). The solubility of 2,4,6-TCP was enhanced a maximum of 72 times especially by NaDC at pH 7.5. In addition, other than great solubilization capacities, NaDC and NaC have the advantages of high biodegradability and biocompatibility as biosurfactants. The adsorption behaviors of 2,4,6-TCP on the surface of soil in the presence of these solubilizers were examined. The results showed that the adsorption isotherms for all studied surfactants matched the Henry adsorption isotherm well. The adsorption mechanisms were explored and the adsorption behaviors of 2,4,6-TCP were affected by different micelle forms of the surfactants based on their critical micelle concentration (CMC). The adsorption process was demonstrated by a redistribution procedure between surfactants in solution and surfactants adsorbed onto the soil surface. In particular, the adsorption of 2,4,6-TCP was almost zero when NaC concentration was above CMC2.The results of our study have important implications for soil remediation and non-point source pollution control.