Remediation of 137 Cs radionuclide in nuclear waste effluents by polymer composite: adsorption kinetics, isotherms and gamma irradiation studies Michael A. Olatunji 1 • Mayeen U. Khandaker 1,2 • Ekramul H. N. M. Mahmud 3 • Yusoff Md. Amin 1 • Janet A. Ademola 4 • Deborah O. Olorode 5 Received: 13 September 2017 Ó Akade ´miai Kiado ´, Budapest, Hungary 2018 Abstract Polypyrrole is incorporated with activated carbon in large size dopant solution and investigated for 137 Cs removal studies. Adsorption experiments showed optimum conditions within 240 min contact time, pH 6, 0.2 g adsorbent and B 100 mg/l adsorbate dose, respectively, while the kinetic data followed pseudo-first-order model. Isotherm data were reproducible by the Langmuir isotherm yielding 23 mg/g maximum sorption capacity. Regeneration of adsorbent was attempted and indicated promising results within three cycles. The surface behavior has also been examined and revealed a well-ordered structure under gamma irradiation. This is a cheap adsorbent to consider and has also proven to possess higher sorption capacity than most highly-cost inorganic materials in use. Keywords Radioactive cesium Á Gamma-irradiation Á Adsorption Á Conducting polymer Á Adsorbent Introduction Nuclear materials have become as important toward achieving a better quality in different fields of our life. Nuclear medicine, diagnoses and treatment of patients employ the use of nuclear materials and in nuclear power plant operation, they are huge sources of electricity supply [1]. However, accumulation of nuclear wastes from these applications can be a potential source of danger not only to the human life but the entire ecosystem. Although haz- ardous radioactive materials released during different applications are effectively and safely managed following worldwide stringent regulatory standards, nuclear power production is still considered a threat due to the potential for the uncontrolled release of radionuclides [2]. Example is the Chernobyl and Fukushima Daichi nuclear power plants disaster that discharged huge amounts of radionu- clides into the atmosphere [3]. Of importance among the radionuclides is 137 Cs, due to its long half-life (30.28 years), environmental mobility, specific radioactiv- ity (up to 3.44 9 10 12 Bq/g in spent nuclear fuel), high fission yield, emission of high energy beta particles (also called heat generator) and relatively strong gamma radia- tion, is considered to warrant special concern [4–6]. In addition, its biological interactions similar to that of potassium have been reported to be responsible to many problems in cardiovascular, immune and respiratory sys- tems [7, 8]. This is why most of the studies regarding the management of nuclear wastes is focused on 137 Cs. Since the primary pathway of radionuclides in food chain is water; hence, to minimize the associated radio- logical risk and facilitate the management of low-level nuclear waste effluents, effective recovery of Cs isotopes is & Michael A. Olatunji olakunlemike@yahoo.com; olakunlemike@siswa.um.edu.my 1 Applied Radiation Laboratory, Department of Physics, University of Malaya, 50603 Kuala Lumpur, Malaysia 2 Center for Radiation Sciences, School of Healthcare and Medical Sciences, Sunway University, 47500 Bandar Sunway, Selangor, Malaysia 3 Polymer Laboratory, Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia 4 Department of Physics, University of Ibadan, Ibadan, Nigeria 5 Department of Physics, University of Lagos, Akoka-Yaba, Nigeria 123 Journal of Radioanalytical and Nuclear Chemistry https://doi.org/10.1007/s10967-018-5875-4