Vol.:(0123456789) 1 3 Journal of Radioanalytical and Nuclear Chemistry https://doi.org/10.1007/s10967-019-07000-y Theoretical modeling of Cu(II), Sr(II), Gd(III), U(VI) sorption from nuclear efuent on PHA resin with experimental validation Mousumi Singha 1  · Sangita Pal 2  · Sujit Chowdhury 1  · K. N. Hareendran 1  · M. L. Sahu 1 Received: 4 September 2019 © Akadémiai Kiadó, Budapest, Hungary 2020 Abstract The sorption capacity of an in–house synthesized novel resin Polyhydraxamic acid(PHA) towards Cu(II), Sr(II), Gd(III), U(VI) ions was studied using batch sorption experiments and was found to be following the order Sr(II) < Cu(II) < U(VI) < Gd(III). The monolayer uptake value (q m ) for Langmuir model was found to be 11.36 mg Sr(II)/g of PHA, 91 mg Cu(II)/g of PHA, 111 mg U(VI)/g of PHA and 125 mg Gd(III)/g of PHA. The sorption dynamics followed pseudo second order kinetics. The pseudo second order rate constant (K 2 ) values were found to be 0.02 g of PHA mg of Sr −1 min −1 , 6.09 × 10 −3 g of PHA mg of Cu −1 min −1 , 9.7 × 10 −5 g of PHA mg of Gd −1 min −1 , 0.018 g of PHA mg of U −1 min −1 . Keywords Sorption · Isotherm · Kinetics · Loaded resin · Rate constant · Uptake Introduction Nuclear energy is emerging as a green energy and is experi- encing continuous growth which in turn is generating waste [1]. Nuclear industry produces waste starting from mining, milling, fuel fabrication, operation of reactors to reprocess- ing of spent fuels [2]. The sources of waste broadly include mine tailings, mill extraction, fabrication process efuents, chemical processing etc. in the Front end. Whereas in the back end processing the mostly encountered radioactive efuents originate from nuclear reactors and reprocessing of spent fuels. All these stages produce aqueous waste con- taining a wide range of metals which are harmful to living beings if disposed untreated. The concentration of elements in these waste are mostly in ppm and above. Many of them have signifcant economic appreciation and even can be reused if recovered. The aqueous phase after removal of met- als may also be recycled in the same operation that implies minimizing water consumption. Uranium(U) is found dur- ing extraction of copper (Cu) ores containing Torbernite ores. The recycled oxide from the uranium fuel fabrication facilities contains substantial amount of Cu(II). Like any other metals copper is potentially toxic and may cause kid- ney failure or lung cancer [3]. In the United States the EPA, under the authority of the Safe Drinking Water Act (SDWA), has set the Maximum Contaminant Level Goal (MCLG) for copper at 1.3 mg/L (or ppm) [4]. Considering stringent regu- latory norms removal of Cu(II) from waste water is neces- sary and also removal of copper associated impurities may facilitate reuse of the aqueous phase. Strontium ( 90 Sr) is one of the most important fssion products of nuclear reactors, and nuclear accidents [5]. The removal of Sr 90 in liquid radioactive wastes is an impor- tant issue for waste disposal. 90 Sr undergoes β − decay with a half-life of 28.79 years which has sufcient migra- tion time and gets incorporated in the food chain [6]. This nuclide endangers human life by inducing cancer, leukemia, and neurological diseases [7, 8]. Strontium-90 is a “bone seeker” that exhibits biochemical behavior similar to cal- cium. The health reference level for strontium was listed as 1.5 milligrams per liter (mg/L) [9–11]. In India Mona- zite is the signifcant source of commercial lanthanides and Monazite-(Sm), (Sm,Gd,Ce,Th) PO 4 is one of the source for gadolinium, that absorbs neutrons and used for shielding in neutron radiography and in nuclear reactors (MO x -pins), nuclear marine propulsion systems as a burnable poison. Gd(III) as gadolinium nitrate is used as neutron poison in the moderator system for regulating and controlling the power generation of Pressurized Heavy Water Reactors (PHWR) * Mousumi Singha mousumi.singha@gmail.com; mousim@barc.gov.in 1 Uranium Extraction Division, Bhabha Atomic Research Center, Mumbai, India 2 Desalination Division, Bhabha Atomic Research Center, Mumbai, India