Akifer Sistemlerinde Depolanan Dnapl Karışımlarının Yerinde Kimyasal Yıkama Teknolojisi İle Islahının İncelenmesi

Year 2022, Volume: 2 Issue: 1, 1 - 8, 29.04.2022

Nihat Hakan Akyol , Taylan Acılıoğlu

Abstract

Trikloroetilen (TCE), tetrakloroetilen (PCE) ve Dikloroetilen (DCE) yeraltı suyu akifer sistemlerinde en çok gözlenen klorlu organik bileşiklerden olup kanserojen etkisinden ötürü insan sağlığı için ciddi tehlike oluşturmaktadır. Bu bileşikler tekil ya da karışım olarak yeraltına genellikle DNAPL olarak girerek çoğunlukla akiferlerin tabanını oluşturan kil ya da ana kaya içerisinde (çanak) yüksek doygunlukta depolanarak uzun süreli çözünmüş faz kirletici kaynağı üretmektedir. Yerinde kimyasal yıkama (ISCF) organik kirleticilerin yeraltından uzaklaştırılması için kullanılan önemli ıslah tekniklerindendir. Çalışmanın amacı; akifer sistemlerin tabanında depolanmış yüksek doygunluktaki DNAPL karışım (TCE, PCE ve DCE) kütlelerinin yıkama ajanları (SDS, Tween 80, MCD ve su) ile ıslah performanslarının etkinliğinin değerlendirilmesidir. Kimyasal yıkama ajanlarıyla (SDS, Tween 80, MCD ve su) heterojen sistemlerde depolanan DNAPL karışım (TCE, PCE, DCE) kaynak zonları büyük oranda ıslah edilmesine rağmen, fiziksel ortam heterojenliği geniş ölçekte aşamalı konsantrasyon davranışı sergilemiştir. Sonuçlara göre, yıkamanın ilk anlarında organik kirletici hidrolik olarak elverişli zonlardan (matriks) gelirken, geç zamanlarda yüksek doygunluktaki hidrolik olarak elverişli olmayan zonlardan (çanak) gelmektedir. Sonuç olarak, bu çalışmadan elde edilecek sonuçlar, ulusal ve uluslararası alandaki önemli bilgi eksikliğine katkıda bulunacak ve arazi uygulamalarının geliştirilmesine yardımcı olacaktır.

Keywords

DNAPL, Dikloroetilen, Kompleks şeker, Tetrakloroetilen, Trikloroetilen, Yüzey aktif madde, DNAPL, Dikloroetilen, Kompleks şeker, Tetrakloroetilen, Trikloroetilen, Yüzey aktif madde

Investigation of In situ chemical flushing technology for DNAPL mixtures resided in aquifer systems

Abstract

Contamination of groundwaters by chlorinated solvents such as trichloroethylene (TCE, tetrachloroethylene (PCE) and dichloroethylene (DCE) is awidespread problem worldwide. These compounds causes serious threat for human health due to being human carcinogen. Chlorinated solvents generally enter the subsurface as single and mixture form of dense non aqueous pHase liquids (DNAPLs) and accumulation generally occurs in aquifers where the DNAPL mass is most likely pooled at the bottom of aquifers and become a long-term aqueous pHase source zone for groundwater contamination. Surfactant enhanced aquifer remediation (SEAR) is groundwater remediation techniques used to remove organic pollutants from the subsurface environment. The objective of the project is to test the reagent (SDS, Tween 80, MCD and water) flushing for DNAPL mixtures (TCE, PCE, DCE) trapped in heterogeneous porous media. Results showed that most of DNAPL source zones were remediated but, physical heterogeneity led to extensive sequential concentration behavior. The results also emphasized that in the early stage, some portion of organic liquid is hydraulically accessible (matrix) whereas the later stage of mass removal was controlled by the more poorly-accessible mass (pool) associated with higher-saturation zones.

Keywords

DNAPL, Cyclodextrine, Dichloroethene, Surfactant, Tetrachloroethene, Trichloroethene

References

• [1] Feenstra S., Cherry J. A. 1988. ‘‘Subsurface contamination by dense non-aqueous phase liquid (DNAPL) chemicals’’, The International Association of Hydrogeologists, Halifax, Nova Scotia.
• [2] Mercer J. W., Cohen R. M. (1990). A review of immiscible fluids in the subsurface: Properties, models, characterization, and remediation, Journal of Contaminant Hydrology, 6, 107-163.
• [3] Boving T. B., Brusseau M. L. (2000). Solubilization and removal of residual trichloroethene from porous media: Comparison of several solubilization agents, Journal of Contaminant Hydrology, (42), 51-67.
• [4] Tick G. R., Lourenso F., Wood A. L., Brusseau M. L. (2003). Pilot-scale demonstration of cyclodextrin as a solubility-enhancement agent for the remediation of a tetrachloroethene-contaminated aquifer, Environmental Science and Technology, 37, 5829-5834.
• [5] Tick, G.R., Rincon, E.A. (2009). Effect of enhanced solubilization agents on dissolution and mass flux from uniformly distributed immiscible liquid trichloroethene (TCE) in homogeneous porous media. Water, Air, & Soil Pollution, 204, 1-4, 315-332.
• [6] Difilippo E. L., Carroll K. C., Brusseau M. L. (2010). Impact of organic-liquid distribution and flow-field heterogeneity on reductions in mass flux, Journal of Contaminant Hydrology, 115, 14–25.
• [7] Akyol N. H., Russo Lee A., Brusseau M. L. (2013). Impact of enhanced-flushing reagents and organic liquid distribution on mass removal and mass discharge reduction, Water, Air and Soil Pollution, 224, 1731.
• [8] Javanbakht G., Goual L. (2016). Impact of Surfactant Structure on NAPL Mobilization and Solubilization in Porous Media. Industrial and Engineering Chemistry Research, 55, 11736-11746.
• [9] Wu B., Li H., Du X., Zhong L., Yang B., Du P., Gu Q., Li F. (2016). Correlation between DNAPL distribution area and dissolvedconcentration in surfactant enhanced aquifer remediation effluent: A two-dimensional flow cell study, Chemosphere, 144, 2142-2149.
• [10] Akyol N. H., Yolcubal I. (2013). Oxidation of Nonaqueous PHase Trichloroethylene with Permanganate in Epikarst, Water, Air and Soil Pollution, 224, 1573, 1-19.
• [11] Akyol, N.H. 2018. Surfactant-enhanced permanganate oxidation on mass-flux reduction and mass removal relationship for pool-dominated TCE source zones in heterogeneous porous media, Water, Air and Soil Pollution, 229, 285. doi.org/10.1007/s11270.
• [12] Akyol, N.H., Turkkan S. (2018). Effect of cyclodextrine-enhanced dissolution on mass removal and mass discharge reduction for TCE source zones in heterogeneous porous media, Water, Air and Soil Pollution, 229.
• [13] Karaoglu, A.G., Copty, N.K., Akyol, N.H., Kilavuz, S.A., Babaei, M. 2019. “Experiments and sensitivity coefficients analysis for multiphase flow model calibration of enhanced DNAPL dissolution” Journal of Contaminant Hydrology 225 (2019) 103515.
• [14] Naval Facilities Engineering Command (Deniz Tesisleri Mühendislik Komutanlığı)