表面活性剂CMC对石油烃污染土壤的增溶

Solubilization of petroleum hydrocarbons in contaminated soil by carboxyl methyl cellulose(CMC)

研究了表面活性剂羧甲基纤维素钠(carboxyl methyl cellulose,CMC)对土壤中石油污染物的增溶作用。通过批实验,对比研究了CMC和十二烷基苯磺酸钠SDBS 2种表面活性剂的增溶效果,探究了CMC浓度、pH、盐度及回用次数对土壤中石油烃增溶效果的影响。研究结果表明,当CMC浓度为0.5%,增溶时间为24 h时,对TPHs浓度为17 695 mg·kg^(-1)的污染土样,TPHs洗脱率高达60%以上。碱性环境有利于石油烃的洗脱,酸性体系会抑制石油烃的洗脱;增溶作用随盐度的增大而显著增大。在利用CMC对污染土壤进行增溶洗脱时,对于TPHs高浓度污染土壤,可以选择将其洗脱液回用1次或者2次;对于TPHs较低浓度污染土壤,可以选择将其洗脱液回用于较高浓度的污染土壤。

Carboxyl methyl cellulose（ CMC） was used to accomplish the effective solubilization of total petroleum hydrocarbons（ TPHs） from contaminated soils. A comparative study was carried out on the solubilization effect by the surfactants of CMC and sodium dodecyl benzene sulfonate（ SDBS） through batch tests. The influences of CMC dosage,pH,salinity,and CMC solution recycling were explored. With care to achieve the optimal addition（ 0. 5%） of CMC to pre-doped contaminated soil,solubilization of TPHs was enhanced in 24 h. For contaminated soil with TPHs of 17 695 mg·kg^-1,over 60% of TPHs was removed. An alkaline condition was favorable for the solubilization of TPHs from contaminated soils,while an acidic condition might inhibit the solubilization of TPHs. With increased salinity,the solubilization of TPHs was enhanced significantly. Used CMC solution,taken after one or two cycles,was usable to solubilize TPHs from highly contaminated soils. For soil only slightly contaminated with TPHs,the used CMC solution could be recycled for the solubilization of TPHs from highly contaminated soil.