Application of Ultrasonic and Bis (2-ethylhexyl) Sulfosuccinate-based Novel Ionic Liquid on Cadmium Extraction

A hydrophobic functional ionic liquid (IL) [N4444]AOT based on sodium bis(2-ethylhexyl)sulfosuccinate anion was designed and synthesized for cadmium extraction. To study the characteristics of [N4444]AOT, fourier transform infrared (FTIR) spectroscopy, hydrogen nuclear magnetic resonance spectroscopy (1H NMR), and thermal gravimetric analysis was used respectively. The extraction ability of [N4444]AOT towards Cd and its ultrasonic assistant were also investigated. Results showed that more than 95.08% of Cd in water solution could be extracted with [N4444]AOT under ultrasonic condition. Results of FTIR and 1H NMR analyses showed that Cd was mainly coordinated with S–O bond provided by [N4444]AOT during extraction. The extraction ratio of Cd from the soil with [N4444]AOT highly reached to 62.57%. Furthermore, [N4444]AOT can extract some stable binded Cd from the soil which existed as a weak acid state, reducible or oxidizable states. Application of [N4444]AOT significantly decreased the bioavailability of Cd in soil. [N4444]AOT could be a good agent for Cd-contaminant soil remediation without changing the soil properties.