IN-SITU REMEDIATION OF TCE SOURCE ZONES BY CHEMICAL FLUSHING: PERFORMANCE OF TWEEN 80 AND SDS

Öz

Chlorinated solvents exist as dense non-aqueous phase liquids (DNAPL) in the subsurface and generally lead to long term groundwater performance, DNAPL mass in the source zone must be controlled contamination. For effective remediation Sodium dodexyl sulfate. or eliminated. Trichloroethylene (TCE) is one of the most important DNAPL phase and widespread groundwater contaminant. In this study, reagent enhanced remediation of residual TCE resided in heterogeneous geological setting using Tween 80, Sodium dodecyl sulfate (SDS) and water was examined. Silica sand media with different median particle diameters were used to represent physical heterogeneity. 2-D Flow-cell experiments were conducted for the objectives. Results showed that residual TCE sources resided in matrix and low-K zones were completely removed due to the effects of solubilization agents (Except water flooding). Performance of reagents on TCE source zone remediation was found to be in the following order: Tween 80> SDS>>Water. The performance of remediation technology was affected by distribution of DNAPLs, type and concentration of reagent and the presence of physical heterogeneity. As a result, the performance of technology depends on the site characteristics which are critical to characterize effective DNAPL remediation strategies for contaminated sites

Anahtar Kelimeler

• DNAPL, Trichloroethylene, Tween 80

TCE KAYNAK ZONLARIN YERİNDE KİMYASAL YIKAMA İLE ISLAHI: TWEEN 80 VE SDS İLE YIKAMA PERFORMANSI

Öz

Klorlu solventler genellikle yeraltında sudan yoğun saf faz (DNAPL) olarak bulunup uzun vadede yeraltı suyu kirliliğine neden olurlar. Etkili bir ıslah performansı için, kaynak zonlarındaki saf faz kütlelerin tamamıyla uzaklaştırılması ya da kontrol edilmesi gerekmektedir. Trikloroetilen (TCE) önemli saf faz (DNAPL) kirletici gruplarından olup yer altı sularında sıkça karşılaşılmaktadır. Çalışma kapsamında, heterojen jeolojik sistemlerde hapsolmuş olan TCE kaynak zonlarının Tween 80, Sodyum dodeksil sülfat (SDS) ve su ile yerinde ıslah performansının başarısı incelenmiştir. Heterojen jeolojik ortamın yansıtılması amacıyla farklı tane boyundaki kuvars kumları kullanılmıştır. Bu kapsamda bir seri 2 boyutlu akım hücresi deneyleri yürütülerek hedeflenen sonuçlara ulaşılması planlanmıştır. Çalışma sonucunda; matriks ve düşük geçirgenlikteki zonların içerisinde bulunan saf faz TCE kütlesi yıkama ajanlarının etkisiyle tamamıyla (su ile yıkama hariç) ıslah edilmiştir. Kullanılan yıkama solüsyonları içerisinde en iyi ıslah performans sıralaması, Tween 80>SDS> su ile yıkama olarak belirlenmiştir. Teknolojinin başarısı özellikle DNAPL dağılımı, yıkama solüsyonu türü ve derişimi ve fiziksel ortam heterojenliğinden önemli oranda etkilenmektedir. Sonuç olarak, arazi çalışmalarında teknolojinin başarısı sahaya özgü olup, bu durum kirlenmiş sahalarda etkili DNAPL ıslah teknolojilerini karakterize etmede oldukça önemlidir

Anahtar Kelimeler

• DNAPL, Trikloroetilen, Tween 80, Sodyum dodeksil sülfat.

Kaynakça

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