In this review, a summary of current legislation applicable to End-of-Life Tyres (ELTs), management of that waste, both in Spain and Europe, and a compilation of existing technologies to enlarge the life of tyres and treatment technologies for material and energy recoveries, are provided. In recent years, there have been a number of studies in the field of treatment of ELTs, therefore applicable emerging technologies as more efficient, clean and costeffective technologies, are discussed. ; Peer Reviewed
A process aimed at the recovery of terbium from liquid solutions using activated carbon (AC) derived from spent coffee grounds (SCG) was assessed. AC was obtained using the hydro-alcoholic treatment of SCG, followed by the physical activation of the as‐obtained product. The AC exhibited both microporous and mesoporous structures, which were shown by the corresponding nitrogen adsorption–desorption isotherms and scanning electron microscopy (SEM) images. In ad-dition, a certain graphitic character was found in the micro‐Raman measurements. By use of this AC, terbium adsorption was investigated, and the influence of solution pH, temperature, and the adsorbent amount on terbium uptake was tested. In addition, adsorption isotherms and kinetic studies were also evaluated. The best fit was found for the type‐1 Langmuir isotherm and pseudo-second‐order kinetics model. Thermodynamic studies revealed that terbium adsorption is an endo-thermic and spontaneous process. Terbium desorption by the use of acidic solutions was also in-vestigated. This work demonstrated that it is possible to recover this valuable metal from liquid solution using the present AC. ; This research has received funding from the European Union's Horizon 2020 research and innovation program under Grant No. 776851 (Car-E Service). We acknowledge the support for the publication fee from the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).
En: 1st Spanish National Conference on Advances in Materials Recycling and Eco – Energy Madrid, 12-13 November 2009.-- Editors: F. A. López, F. Puertas, F. J. Alguacil and A. Guerrero.-- 4 pages, 2 tables. ; Phosphogypsum (PG) is a hazardous waste associated with the phosphoric acid production using the wet process. PG is considered a relatively high level natural uranium series radionuclide material, which provokes a negative environmental impact and many restrictions on the use of the PG waste (only 15% of the PG generated is recycled in agriculture, in gypsum board and cement industries). The US-EPA has classified PG as Technologically Enhanced Naturally Occurring Radioactive Material (TENORM). Legislations and standard regulations have established maximum limits for PG radionuclides concentration and exposure. ; The authors are grateful to the Spanish National R&D&I Plan (Project CTQ2008-02012/PPQ) for the financial support of this study. Hanan Tayibi is grateful to CSIC for an I3P contract (I3PDR-6-01). ; Peer reviewed
The new phosphogypsum (PG) waste management policy allowed to reduce the negative environmental impact of this residue by finding better alternatives uses with an extremely limited radiological impact. Building material could be one of these alternatives that could lead to the production of final products with good mechanical properties and very limited radionuclides content. The optimization of the radioactive levels in the building materials when PG is used for its production requires the previous knowledge of the content of naturally occurring radionuclides in the PG waste. This article aims the radioactive characterization of two different PG sources (from Spain (Fertiberia S.A., Huelva) and Tunisia (Sfax), before being incorporated in building materials. For this purpose, the natural selected radionuclides content belonging to uranium and thorium decay series and 40K was determined, by means of two different methods: i) gamma spectrometry with high-purity germanium detectors and ii) laser-induced kinetic phosphorimetry (KPA-11 Chemcheck Instruments Inc., Richland, WA). Also, the semiquantitative chemical composition, the mineralogical study and the morphological aspect of the PG samples were analysed. The results obtained from both techniques show that 226Ra and 210Po are the main source of the radioactivity in both studied PG samples. However, PG samples from Tunisia present low natural radionuclide levels (30.7 Bq·kg¿1 average value for 238U, 188 Bq·kg¿1(226Ra), 163 Bq·kg¿1(210Pb), 12.4 Bq·kg¿1 (232Th) compared to the level of natural radionuclides in PG samples from Huelva (102 Bq·kg¿1 average value for 238U, 520 Bq·kg¿1(226Ra), 881 Bq·kg-1(210Pb) and 8 Bq·kg-1 (232Th). Both PG fulfil European Commission Recommendation (ECR) for the maximum activity concentrations of naturally-occurring radionuclides for industrial by product used in building materials in the European Union. ; Peer Reviewed
