Algerian journal of engineering and technology

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Browsing Algerian journal of engineering and technology by Subject "Adsorption"

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    Comparative study on the performance of natural and synthesized adsorbents onto uranium (VI) sorption
    (University of Eloued جامعة الوادي, 2023-11-08) Bayoua Naima- Houhounea Fatima-KhemaissiaSihem- AmarbHamid Aït- LouniscAli
    The aim of this study is to compare the performance of natural and synthesized material to adsorb uranium. Synthesized Silico-Alumino-Phosphate (SAPO) material is compared to raw and chemically activated Algerian Aleppo pine sawdust (Raw-AAPS and CA-AAPS). The uranium sorption parameters, isotherms modelling, kinetic modelling and decontamination factor results, showed that adsorbents used are effective for the removal of uranium (VI) ions and the performance of the adsorbents follows the order: SAPO > CA-AAPS> Raw-AAPS. The natural material presents less sorption capacity comparatively to the synthesized adsorbent, but it is economically favored because of its abundance in nature and its low cost.
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    Effects of desilication and dealumination of NaA zeolite on uranium recovery from aqueous effluents
    (University of Eloued جامعة الوادي, 2023-10-06) OudjerFaiza- KhemaissiaSihem- MouhelbiLeila -OuttasSihem- HammacheYasmina- MeddourYasmine- Chouial Habiba.
    Different processes for recovering uranium from raffinates and effluents generated throughout the nuclear fuel cycle are implemented. The adsorption process has been widely adopted in the uranium recovery from aqueous solution, due to its simplicity, rapid kinetics, wide applicability, cost-effectiveness and non-secondary contamination. Adsorption performance is directly determined by the appropriate adsorbents for the target compounds. Zeolite is one of the most commonly used materials for adsorption due to its low cost, high chemical and thermal stability. However, its relatively low sorption capacity limits its performance and feasibility. Many modification strategies have been used to improve its performance. Desilication and dealumination are among the processes that improve accessibility to active sites located inside the zeolite framework and can limit diffusion constraints through the creation of a secondary network of large pores (mesopores) connected to native micropores. In this study, the synthesized and modified NaA zeolite were characterized by powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption-desorption analysis. Uranium adsorption capacities were found to be around 42 mg/g, 27 mg/g and 10 mg/g for desilicated NaA, NaA and dealuminated NaA respectively. The desilicated NaA material showed better selectivity compared to the starting material. The adsorption of UO22+ ions follows the Langmuir isotherm and the pseudo-second-order kinetic model. The values of uranium desorption 36%, 82% et 87% for NaA, desilicated NaA and dealuminated NaA have been reached using 1M HNO3 for one treatment cycle. The treatment of the real effluent with the three adsorbents showed a recovery of around 62% in uranium for NaA and desilicated NaA, for dealuminated NaA it was around 19% following the coadsorption of competing metal ions
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    Gamma spectrometry technique application to the 60Co sorption onto IRN-77 resin from radioactive wastewater: Equilibrium, Kinetic and Thermodynamic investigations
    (University of Eloued جامعة الوادي, 2023-11-03) Achour Souad-Nibou Djamel- Amokrane Samira
    The performance of synthetic ion exchange resin IRN-77 have been studied in this work in order to use it as an adsorbent to remove radioactive isotope 60Co from nuclear wastewater by the sorption process, using the gamma spectrometry technique. The resin simple was identified using SEM and FTIR infrared spectrometry. The gamma radiation acquisition emitted from the fixed radioactive 60Co onto IRN-77 solid samples was carried out using the gamma spectrometry chain, equipped with an HPGe semi-conductor detector with high-resolution. Various factors were considered for the sorption process study such as 60Co concentration, contact time and temperature. The maximum adsorption capacity of the IRN-77 samples was determined by studying the adsorption isotherms; Kinetics models including thermodynamics were also studied and investigated. The experimental results showed that the adsorption reaction was adjustable to the pseudo-first-order and the Langmuir model was found to describe best the experimental results by obtaining a very important maximum adsorption quantity of 10.620 μCi of 60Co per 1 gram of IRN-77 adsorbent. A dimensionless separation factor RL was used to judge the favorable adsorption. The adsorption capacity of 60Co ions onto IRN-77 particles increased with the increasing of temperature. The values of the thermodynamic parameters have shown that the 60Co ions adsorption process was endothermic and favored at high temperatures with a positive value of the enthalpy ΔH° of 23,54 kJ/mol. The free energy’s values ΔG◦ are positive over the whole temperature range. The specific activities of the fixed 60Co radionuclide allow evaluating the solid samples IRN-77 resin's sorption capacity.