Dept. of Environmental Sciences and Biotechnology, Hallym University, Chuncheon, Gangwon-do 24252, Republic of Korea.
Dept. of Environmental Sciences and Biotechnology, Hallym University, Chuncheon, Gangwon-do 24252, Republic of Korea.
J Contam Hydrol. 2018 Mar;210:42-49. doi: 10.1016/j.jconhyd.2018.02.004. Epub 2018 Feb 16.
The effect of groundwater viscosity control on the performance of surfactant-enhanced air sparging (SEAS) was investigated using 1- and 2-dimensional (1-D and 2-D) bench-scale physical models. The viscosity of groundwater was controlled by a thickener, sodium carboxymethylcellulose (SCMC), while an anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), was used to control the surface tension of groundwater. When resident DI water was displaced with a SCMC solution (500 mg/L), a SDBS solution (200 mg/L), and a solution with both SCMC (500 mg/L) and SDBS (200 mg/L), the air saturation for sand-packed columns achieved by air sparging increased by 9.5%, 128%, and 154%, respectively, (compared to that of the DI water-saturated column). When the resident water contained SCMC, the minimum air pressure necessary for air sparging processes increased, which is considered to be responsible for the increased air saturation. The extent of the sparging influence zone achieved during the air sparging process using the 2-D model was also affected by viscosity control. Larger sparging influence zones (de-saturated zone due to air injection) were observed for the air sparging processes using the 2-D model initially saturated with high-viscosity solutions, than those without a thickener in the aqueous solution. The enhanced air saturations using SCMC for the 1-D air sparging experiment improved the degradative performance of gaseous oxidation agent (ozone) during air sparging, as measured by the disappearance of fluorescence (fluorescein sodium salt). Based on the experimental evidence generated in this study, the addition of a thickener in the aqueous solution prior to air sparging increased the degree of air saturation and the sparging influence zone, and enhanced the remedial potential of SEAS for contaminated aquifers.
本研究采用一维（1-D）和二维（2-D） bench-scale 物理模型，考察了地下水粘度控制对表面活性剂强化空气注入（SEAS）性能的影响。采用增稠剂羧甲基纤维素钠（SCMC）控制地下水的粘度，采用阴离子表面活性剂十二烷基苯磺酸钠（SDBS）控制地下水的表面张力。当用 SCMC 溶液（500mg/L）、SDBS 溶液（200mg/L）和 SCMC（500mg/L）和 SDBS（200mg/L）溶液驱替惰性 DI 水时，空气注入使砂柱的空气饱和度分别增加了 9.5%、128%和 154%（与 DI 水饱和柱相比）。当原状水含有 SCMC 时，空气注入过程所需的最小空气压力增加，这被认为是空气饱和度增加的原因。2-D 模型中空气注入过程的充气影响区的范围也受到粘度控制的影响。在 2-D 模型中，最初用高粘度溶液饱和时，空气注入过程中的充气影响区（由于空气注入而脱气的区域）大于没有增稠剂的水溶液。1-D 空气注入实验中，SCMC 的加入提高了空气注入过程中气态氧化剂（臭氧）的降解性能，这可以通过荧光（荧光素钠盐）的消失来衡量。根据本研究的实验证据，在空气注入前向水溶液中添加增稠剂可以提高空气饱和度和充气影响区的程度，并增强 SEAS 对受污染含水层的修复潜力。
