Research On Surfactant Enhanced Pump And Treat Remediation Of Typical DNAPLs In Saturated Porous Media

Soil and groundwater pollution by DNAPLs pose a persistent environmental problem and a serious threat to human survival environment with the leakage of oil pipelines, storage tanks and the widely use of organic solvent. DNAPLs that undissolved or slightly solubled in water would exist as a single phase after leaked. It shows the special physical and chemical properties, such as stable, difficult to degradation, and has strong toxicity. The traditional Pump and Treat remediation are hampered by its unique properties. The surfactants enhanced pump and treat remediation arised in order to improve the repair efficiency of DNAPLs.The quartz sand was selected as a representative of the porous medium. The1,2-dichloroethane and tetrachloroethylene were selected as the representative of the DNAPLs. In order to verify the feasibility of this technology, the dye tracer method combined with image analysis were used in the two-dimensional visual sand box. The whole process of DNAPLs were showed when using the surfactant enhanced pump and treat remediation. The effluent concentration were also measured by the GC-MS. In order to verify the efficiency of this technology, the traditional pump and treat remediation and the surfactant enhanced pump and treat remediation were compared. In order to understand the influence of various factors of this technology, the orthogonal experiments were studied.The feasibility was verified through the dye tracer method combined with image analysis in the two-dimensional visual sand box. The efficiency was verified through the compared with the removal of total amount in the traditional pump and treat remediation and the surfactant enhanced pump and treat remediation. The influence sequence was:the SDBS concentration> the size of porous medium> the velocity of extraction processing according to the1,2-dichloroethane orthogonal experiments. The influence sequence was:the kind of Surfactant> the size of porous medium in the tetrachloroethylene orthogonal experiments. The surfactant was the root reason of the morphological changes. The1,2-dichloroethane mainly embodied in a horizontal flow and the tetrachloroethylene mainly embodied in vertical upward flow. The solutioning cooperated closely with the flowing in the SDBS enhanced pump and treat remediation of1,2-dichloroethane and in the Tx100enhanced pump and treat remediation of tetrachloroethylene. However, the flowing brought the risk source diffusion in the SDBS enhanced pump and treat remediation of tetrachloroethylene experiment.