Properties Of Acetamide-organic Acid Eutectic Ionic Liquid And Its Application In Soil Heavy Metal Remediation

In order to find a eutectic ionic liquid with better extraction and remediation effect on heavy metals in soil,two eutectic ionic liquids prepared from acetamide-organic acid were studied in this paper.The basic properties were determined and respective experiments were carried out to extract heavy metals from soils at different temperatures and concentrations.The prepared eutectic ionic liquid was characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy.The results showed that acetone can be used as a preferred solvent for quantitative analysis.The densities,viscose,surface tensions and electrical conductivity of acetamide-citric acid and acetamide-alanine eutectic ionic liquids at different concentrations（303.15³43.15 K）were determined.The results showed that the density,viscosity,surface tension and electrical conductivity of pure ionic liquids follow the linear equation with temperature,and the correlation coefficients are all higher than 0.99.In this paper,the extraction experiments of heavy metals in soil by acetamide-citric acid eutectic ionic liquid and acetamide-alanine eutectic ionic liquid were carried out,and the optimum conditions for the ionic liquid in the extraction process were analyzed.The results showed that the eutectic ionic liquid prepared by acetamide-citric acid can reach the maximum extraction efficiency of 99.51%at a concentration of 2 mol·L^-1,a constant temperature of 35℃and an oscillation reaction time of 3 h.The ratio of ionic liquid viscosity to Cu²⁺extraction rate was the lowest.The nonlinear programming model was established.Using MATLAB software optimization,the eutectic ionic liquid can be obtained at 35℃when the ionic liquid concentration was 1.94 mol·L^-1.A relatively high extraction rate of 95.77%was achieved at a lower viscosity.The maximum extraction efficiency of acetamide-alanine eutectic ionic liquid for Cd²⁺at a concentration of 0.6mol·L^-1can reach 99.67%.The ionic liquid has a more outstanding extraction effect than other heavy metal extract ants.