| Alcohol cosolvent only or with surfactant increases solubilization of PCBs and reduces interfacial tension between washing solution and PCBs, which are very important for the removal of residual PCBs in sandy soils. Through the experiment of the alcohol oscillating solubilization and reducing interfacial tension between alcohol and PCBs oil, it was analyzed that alcohol cosolvent increases solubilization of PCBs and reduces interfacial tension between solution and PCBs oil, and the influence of alcohol on the Triton X-100 solution increases solubilization and reduces the interfacial tension between the solution and PCBs oil. The experimental results show that: the reduction of interfacial tension is inversely proportional to alcohol concentration, the number of carbon atoms in an alcohol molecule, the best concentration of methanol, ethanol, isopropanol is 70%, 55%, 40% respectively, the best removal efficiency of PCBs by desorption reaches 90% and above. The interfacial tension between the solution of Triton X-100 and PCBs oil is inversely proportional to Triton X-100 concentration. When Triton X-100 concentration is lower than 3 000 mg/L, the removal efficiency of PCBs by Triton X-100 alone is higher than that by Triton X-100 with 10% ethanol or 10% isopropanol. When Triton X-100 concentration is between 3 000 mg/L and 7 500 mg/L, removal efficiency by the three groups varies in difference. When Triton X-100 concentration is 10 000 mg/L, the removal efficiency by Triton X-100 alone, with 10% ethanol, with 10% isopropanol is 80.9%, 90.36%, 89.36% respectively. Therefore it is concluded from the experimental results that: Alcohols weaken the ability of the Triton X-100 solution increasing the solubilization of PCBs and reducing the interfacial tension between the solution and PCBs oil when alcohol is used with Triton X-100. However, when Triton X-100 concentration is greater than 3 000 mg/L, that weakening effect has been very little. |
