ADVANCES IN ENVIRONMENTAL BIOTECHNOLOGY AND ENGINEERING 2016 Study of plasma off-gas treatment from spent ion exchange resin pyrolysis Hernán Ariel Castro 1,2 & Vittorio Luca 1 & Hugo Luis Banchi 2,3 Received: 12 December 2016 /Accepted: 8 March 2017 # Springer-Verlag Berlin Heidelberg 2017 Abstract Polystyrene divinylbenzene-based ion exchange resins are employed extensively within nuclear power plants (NPPs) and research reactors for purification and chemical control of the cooling water system. To maintain the highest possible water quality, the resins are regularly replaced as they become contaminated with a range of isotopes derived from compromised fuel elements as well as corrosion and activation products including 14 C, 60 Co, 90 Sr, 129 I, and 137 Cs. Such spent resins constitute a major proportion (in volume terms) of the solid radioactive waste generated by the nuclear industry. Several treatment and conditioning techniques have been de- veloped with a view toward reducing the spent resin volume and generating a stable waste product suitable for long-term storage and disposal. Between them, pyrolysis emerges as an attractive option. Previous work of our group suggests that the pyrolysis treatment of the resins at low temperatures between 300 and 350 °C resulted in a stable waste product with a significant volume reduction (>50%) and characteristics suit- able for long-term storage and/or disposal. However, another important issue to take into account is the complexity of the off-gas generated during the process and the different techni- cal alternatives for its conditioning. Ongoing work addresses the characterization of the ion exchange resin treatment’ s off- gas. Additionally, the application of plasma technology for the treatment of the off-gas current was studied as an alternative to more conventional processes utilizing oil- or gas-fired post- combustion chambers operating at temperatures in excess of 1000 °C. A laboratory-scale flow reactor, using inductively coupled plasma, operating under sub-atmospheric conditions was developed. Fundamental experiments using model com- pounds have been performed, demonstrating a high destruc- tion and removal ratio (>99.99%) for different reaction media, at low reactor temperatures and moderate power consumption. The role of H 2 O as an important participant of the oxidation mechanisms in plasma conditions was established. The com- bination of both processes could represent a simple, safe, and effective alternative for treating spent ion exchange resins with a large reduction of generated gaseous byproducts in fuel cycle facilities where processes that utilize open flames are undesirable. Keywords Spent ion exchange resins . Nuclear waste . Pyrolysis . Plasma . Off-gas treatment Introduction Polymeric ion exchange resins are indispensable materials across a broad spectrum of industries (Alexandratos 2009), including the nuclear industry. Exhausted ion exchange resins are reusable on several industrial applications after a simple regeneration method (Maul et al. 2014). However, after sev- eral cycles, ion exchange materials become unusable and must be discarded. The waste resin is considered nondegradable and is a potential environmental risk depending on the Responsible editor: Bingcai Pan * Hugo Luis Banchi bianchi@cnea.gov.ar 1 Programa Nacional de Gestión de Residuos Radiactivos, Comisión Nacional de Energía Atómica, Centro Atómico Constituyentes, Av. General Paz 1499, 1650 San Martín, Buenos Aires, Argentina 2 Escuela de Ciencia y Tecnología, Universidad Nacional de General San Martín, Campus Miguelete, Martín de Irigoyen 3100, 1650 San Martín, Argentina 3 Gerencia de Química, Comisión Nacional de Energía Atómica, Centro Atómico Constituyentes, Av. General Paz 1499, 1650 San Martín, Buenos Aires, Argentina Environ Sci Pollut Res DOI 10.1007/s11356-017-8766-2