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

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

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