Highly efficient sulfonated poly (ether ether ketone) (sPEEK) adsorbent for removal of uranium (VI) from aqueous solution

Sulfonated polyether ether ketone (sPEEK) polymer matrix was used as adsorbent for uranyl adsorption for first time. sPEEK showed high affinity against uranyl cations and the maximum adsorption capacity was found as 0.82 mmol/g. The maximum adsorption was achieved at pH 6. The adsorption kinetic was described by pseudo -second order model. Pore diffusion was involved in adsorption but not rate controlling step. The adsorption reaction is endothermic, and the activation energy is 85.8 kJ/mol. The desorption kinetics into 2 M HNO3, 0.1 M Na2CO3, 0.05 M EDTA and 5 % citric acid solutions were searched, and 99 % desorption was achieved when 0.05 M EDTA and 2 M HNO3 were used as leaching solution. The recovery efficiency decreased from 98 % to 88 % in 0.05 M EDTA solution and from 96 % to 86 % in 2 M HNO3 solution at the end of the fifth cycle. Uranium removal and recovery from liquid waste generated by mining and nuclear plants is of great importance. This study presents an opportunity for highly efficient removal using a low-cost and easily handled sorbent, as well as high recovery of uranyl ions with the aid of a common eluent, allowing for five cycles.