Katyonik Polimer Katkılı Geosentetik Kil Örtülerin Farklı Tuz Çözeltileri ile Etkileşimi

Öz

Geosentetik kil örtü (GKÖ), düşük hidrolik iletkenliği sayesinde atık depolama alanlarında bariyer özelliği ile kullanılan bir kaplama malzemesidir. Bu çalışmada, GKÖ’nün bentonit bileşenine sırasıyla kütlece %0.5, %1 ve %2 oranlarında katyonik polimer eklenmiş ve üç eksenli hidrolik iletkenlik ile serbest şişme deneyleri yapılarak GKÖ’nün sırasıyla 0.1 M KCl, 0.5 M KCl ve 0.1 M MgCl₂ tuz çözeltilerinde hidrolik performansı irdelenmiştir. Sonuç olarak GKÖ’ye 0.1 M KCl çözeltisinde %0.5 katyonik polimer eklenmesi, hidrolik iletkenliği yaklaşık 0.13 katına, 0.5 M KCl ile 0.1 M MgCl₂ çözeltilerinde ise %1 katyonik polimer eklenmesi,  hidrolik iletkenliği sırasıyla yaklaşık 0.18 ve 0.08 katına düşürerek gerekli hidrolik performansı sağlamıştır. GKÖ’ye daha fazla polimer eklemek, hidrolik iletkenliği ya değiştirmemiş ya da artırmıştır. GKÖ’nün şişme indeksi de %2 miktarına kadar katyonik polimer eklenmesi sonucunda artmıştır. Katyonik polimerin hidrolik iletkenlik üzerindeki etkileri polimer-bentonit-tuz çözeltisi arasındaki elektrostatik kuvvetler ile, şişme indeksi üzerindeki etkileri ise difüz çift tabaka ile ilişkilendirilmiştir. Tuz çözeltilerinin konsantrasyonunu ve katyon değerliğini artırmak ise hidrolik iletkenliği artırıp şişme indeksini azaltmıştır. Deney sonuçlarına göre kullanılan katyonik polimer, GKÖ’nün hidrolik özelliklerini iyileştirerek tuz çözeltilerinde yeterli hidrolik performansta kullanımını sağlamıştır.

Anahtar Kelimeler

• Atık Depolama Alanı,Geosentetik Kil Örtü,Katyonik Polimer,Şişme İndeksi,Hidrolik İletkenlik,Tuz Çözeltisi

Interaction of Cationic Polymer-Treated Geosynthetic Clay Liners with Various Saline Solutions

Öz

Geosynthetic clay liner (GCL) is a lining material that is used in waste containment facilities with its low hydraulic conductivity and barrier capability. In this study, %0.5, %1 and %2 cationic polymer by mass was added respectively to the bentonite component of the GCLs and triaxial hydraulic conductivity and free swell tests were performed on the GCLs that were permeated with 0.1 M KCl, 0.5 M KCl and 0.1 M MgCl₂ saline solutions respectively in order to evaluate the hydraulic performance of the GCL. As a result, %0.5 cationic polymer in 0.1 M KCl solution and %1 cationic polymer in 0.5 M KCl and 0.1 M MgCl₂ solutions improved the hydraulic performance of the GCL by causing almost 0.13, 0.18 and 0.08 times decrease in hydraulic conductivity respectively. However, additional polymer treatment resulted in either no change or increase in hydraulic conductivity. Furthermore, swell index of the GCL increased by adding up to an amount of %2 cationic polymer to the GCL. The effect of adding cationic polymer to the GCL on hydraulic conductivity and swell index was related to the electrostatic forces among polymer-bentonite-saline solution and diffuse double layer respectively. Increasing the concentration and valence of the cation in the saline solutions resulted in both increase in hydraulic conductivity and decrease in swell index. According to the test results, the cationic polymer improved the hydraulic properties of the GCL and resulted in a satisfactory hydraulic performance in saline solutions.

Anahtar Kelimeler

• Waste Containment Facility,Geosynthetic Clay Liner,Hydraulic Conductivity,Cationic Polymer,Swell Index,Saline Solution

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