Ekstraksiyon Kromatografi İle Düşük Düzey Laboratuvar Atık Çözeltilerinden Uranyum Ayırımı - The Separation Uranium From Low Level Radioactivite Waste Solutions By Extraction Chromatography

Ekstraksiyon Kromatografi Ile Dusuk Duzey Laboratuvar Atik Cozeltilerinden Uranyum Ayirimi Ekstraksiyon kromatografisi, son yillarda aktinitlerin ayrimi ve kazaniminda uygulanmakta olan analitik bir tekniktir. Bu calismada, ekstraksiyon kromatografi teknigi ile dusuk duzey radyoaktif atik cozeltisindeki uranyum(VI)‘ nin onderisimi ve ayrimi icin bir metod gelistirilmistir. Calismanin ilk kisminda,  standart uranyum cozeltisi ile denemeler yapilmis olup, uranyum, trioktilfosfin oksit (TOPO) ile yuklu silika jel kolonda ekstrakte edilmistir. Belirlenen optimum kosullarda, 1 M HNO 3 +1 M NaNO 3 ortaminda uranyumun ekstraksiyon verimi %99,5±1,5 bulunmustur. Degisik elusyon cozeltileri ile yapilan elusyon denemelerinde en yuksek elusyon verimleri; 0,5 M HCl cozeltisi icin % 83,6, 0,5 M H 3 PO 4 cozeltisi icin %84,3, 1 M H 3 PO 4 cozeltisi icin %97,6 ve 9 M HClO 4 cozeltisi icin %92,3 olarak saptanmistir. Metod dogrudan dusuk duzey laboratuvar atik cozeltisine uygulandiginda uranyum ekstraksiyon verimleri 3 M HNO 3 icin %52,8; 1 M HNO 3 +1 M NaNO 3 icin %67,3 olarak saptanmistir. Atik cozeltisine 1:1 HClO 4 ve %35’ lik H 2 O 2 ile onislem yapildiginda, 1 M HNO 3 +1 M NaNO 3 ortaminda uranyum ekstraksiyon verimi %95,7±2,3’ ye ulasmistir. Kolondan once, 0,5 M H 2 SO 4 cozeltisi ile toryum % 89,2±3,1 ve daha sonra 9 M HClO 4 cozeltisi ile uranyum %94,1±1,8  verim ile  eluye edilmistir The Separation Uranium  From Low Level Radioactivite Waste Solutions By Extraction Chromatography In recent years, extraction chromatography is an analytical technique which is applied for the separation and recovery of actinides. In this study, a method for the preconcentation and separation uranium(VI)  in low level radioactivite waste solution has been developed using extraction chromotograpy. In the first stage of the work, experiments were performend by standart uranium solutions and uranium was extracted on silica gel column coated with trioctylphosphine oxide. At determined optimum conditions, the yield of the uranium extraction in 1 M HNO 3 +1 M NaNO 3 medium was found as 99.5±1.5%. Various stripping reactants tested in the experiments were as follows; 0.5 M HCl, 0.5 M H 3 PO 4 , 1 M H 3 PO 4 and9 M HClO 4 , 83.6%,  84.3%, 97.6% and  92.3%, respectively. By applying this method to the low-level laboratory waste solutions, uranium extraction yields in 3 M HNO 3 and 1 M HNO 3 +1 M NaNO 3 were found as 52.8%, 67.3%, respectively. After the pretreatment with 4 mL 1:1 HClO 4 and 6 mL 35% H 2 O 2 , the uranium extraction yield reached to 95.7±2.3% in 1 M HNO 3 +1 M NaNO 3 . Firstly, thorium was eluted with 10 mL 0.5 M H 2 SO 4 and then uranium was eluted with 20 mL 9 M HClO 4 . The recoveries were 89.2±3.1% and  94.1±1.8%, respectively.