Removal of recalcitrant organic compounds from an industrial complex effluent by heterogeneous Fenton-type treatment

Because of their chemical complexity, industrial chemi-mechanical pulping effluents are evaporated and burned, in spite of the high associated cost involved in these processes. The aim of this study was to remove recalcitrant compounds from this kind of wastewater using a Fenton-type treatment. The main parameters involved in the process and their influence on the results were determined. Homemade catalysts based on CuO, Fe2O3, NiO and ZnO, supported on γ-Al2O3 have been tested for catalytic oxidation, and the CuO/γ- Al2O3 catalysts showed the greatest effect on total organic carbon (TOC) reduction (52.7%). A series of twolevel factorial experiments was subsequently applied to evaluate the most favorable range of conditions for CuO/γ-Al2O3 application. The studied variables were hydrogen peroxide concentration ([H2O2], g/L), active phase content (metal oxide supported on alumina, %), mass of catalyst (metal oxide/alumina system, g), and reaction temperature (°C). The highest reduction of all parameters was obtained at the superior level of all variables with CuO/γ-Al2O3, achieving reductions of chemical oxygen demand (COD) and TOC between 40 and 50%. Increasing catalyst mass did not produce additional benefit. This variable has a significant effect only on the reduction of aromatic compounds. At its low level, reduction in aromatic content exceeded 80%. Color reduction was influenced only by temperature (maximum reduction of 90%)Fil: Covinich, Laura Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Felissia, Fernando Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Fenoglio, Rosa Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Area, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentin

Geopolymers based on spent catalyst residue from a fluid catalytic cracking (FCC) process

This paper assesses the use of alkali activation technology in the valorization of a spent fluid catalytic cracking (FCC) catalyst, which is a residue derived from the oil-cracking process, to produce geopolymer binders. In particular, the effects of activation conditions on the structural characteristics of the spent catalyst- based geopolymers are determined. The zeolitic phases present in the spent catalyst are the main phases participating in the geopolymerization reaction, which is driven by the conversion of the zeolitic material to a highly Al-substituted aluminosilicate binder gel. Higher alkali content and SiO2/Na2O ratio lead to a denser structure with a higher degree of geopolymer gel formation and increased degree of crosslinking, as identified through 29Si MAS NMR. These results highlight the feasibility of using spent FCC catalyst as a precursor for geopolymer production.This study was sponsored by research scholarship BES-2008-002440 and EEBB-2011-43847 from the Ministerio de Ciencia y Tecnologia of Spain, the European regional development fund (FEDER), and the Universitat Politecnica de Valencia (Spain). The participation of SAB and JLP was funded by the Australian Research Council through the Discovery Projects program, and also including partial funding through the Particulate Fluids Processing Centre, a Special Research Centre of the ARC. The authors wish to acknowledge the Advanced Microscopy Facility at The University of Melbourne for assistance with the electron microscopy experiments conducted in this study.Rodriguez Martinez, ED.; Bernal, SA.; Provis, JL.; Gehman, JD.; Monzó Balbuena, JM.; Paya Bernabeu, JJ.; Borrachero Rosado, MV. (2013). Geopolymers based on spent catalyst residue from a fluid catalytic cracking (FCC) process. Fuel. 109:493-502. https://doi.org/10.1016/j.fuel.2013.02.053S49350210

Epitaxial synthesis of Ni–MoS₂/Ti₃C₂T_x MXene heterostructures for hydrodesulfurization

A facile and efficient method is adopted to intercalate promoter and few-layered MoS2 in Ti3C2Tx MXene for high hydrodesulfurization activity via an in situ thermal conversion process.</p

PAX5α and PAX5β mRNA expression in breast Cancer: Relation to serum P53 and MMP2

Background: Many studies evaluated the role of paired box gene 5 (PAX5) in breast cancer. However, few investigated PAX5α and PAX5β isoforms individually. Objective: The aim of the present study is to evaluate mRNA expression of PAX5α and PAX5β in breast cancer and assessing their underlying pathological roles through investigating their correlations to matrix metalloproteinase2 (MMP2), p53 and cancer antigen 15-3 (CA15-3). Methods: Evaluation of PAX5α and PAX5β RNA expression in breast tissue samples was done by real-time PCR, serum MMP2 and p53 by ELISA and CA15-3 by chemiluminescent immunoassay in 55 infiltrating ductal carcinoma patients, 25 fibroadenoma patients and 15 control females who underwent plastic breast surgery. Results: PAX5α RNA was reduced while PAX5b RNA was elevated in breast cancer patients compared to other groups (p &lt; 0.01). The best cutoff value of PAX5α was 61.15 with 78.2% sensitivity and 90% specificity and for PAX5β it was P2.01 with 83.6% sensitivity and 82.5% specificity. The RNA expression of PAX5β was higher in advanced grades and stages (p &lt; 0.01), and significantly correlated to p53 (r: 0.51, p &lt; 0.01), and CA15-3 (r: 0.45, p &lt; 0.01). Moreover, PAX5α was negatively correlated to PAX5β (r: 0.42, p &lt; 0.01), p53 (r: 0.53, p &lt; 0.01) and MMP2 (r: 0.22, p &lt; 0.05). Conclusions: The downregulation of PAX5α with upregulation of PAX5β RNA expressions could highlight the possible oncogenic role of PAX5 as a transcriptional factor in tumorigenesis and progression of breast cancer

Exploring enthalpies of CO2 and N2 adsorption on Zn- and Co-based zeolitic frameworks at varying temperatures and pressures

This study investigates the thermodynamics of CO2 and N2 adsorption on zeolitic imidazolate frameworks (ZIFs), focusing on the effects of metal ions under varying temperatures and pressures. Zn- and Co-based ZIFs were synthesized using 2-methylimidazole and characterized by XRD, FT-IR, Raman spectroscopy, and BET isotherms, confirming high microporosity. Gas adsorption experiments were performed at pressures up to 3000 kPa and temperatures between 268 and 323 K. The CO2 adsorption capacities vary from 274 to 157 cm³/g, while N2 ranged from 67 to 29 cm³/g as temperature increased. The synergistic dynamics of temperature and pressure enhanced CO2 diffusion and induced pore structure changes via a gate-opening mechanism. Isosteric enthalpy (ΔHads) values, determined using Freundlich-Langmuir/Clausius-Clapeyron and virial fits, were -22 ± 5 kJ/mol for CO2 and -15 ± 2 kJ/mol for N2, confirming that physisorption is the dominant mechanism. Gibbs free energy (ΔGads) for CO2 ranged from -12 to -18 kJ/mol, and entropy (ΔSads) from -0.01 to -0.03 kJ/mol/K, suggesting spontaneous and thermodynamically favorable CO2 adsorption, though spontaneity decreased with rising temperature. ZIFs containing Zn exhibited high CO2 adsorption capacity, while those with Co showed better CO2 selectivity over N2, highlighting their potential for efficient CO2 capture under various temperature and pressure conditions