Wet peroxide oxidation of paracetamol using Fe/Co-pillared clay catalysts prepared from natural clays

This work deals with the catalytic wet peroxide oxidation of paracetamol, considered as model emerging pollutant, using as catalysts low-cost materials based on pillared clays prepared from natural clays. Pillared clays were prepared successfully through a pillaring solution containing cobalt and iron. The prepared clays allow to remove completely the pollutant after 8 h of reaction at 80 ºC, initial pH 3.5, Ccatalyst = 2.5 g L-1, Cpollutant = 100 mg L-1 and CH2O2 = 472 mg L-1, whereas in the non-catalytic run only 20% removal of pollutant was obtained after 24 h at the same operating conditions.This work was financially supported by project “VALORCOMP - Valorización de compost y otros desechos procedentes de la fracción orgánica de los residuos municipales”, 0119_VALORCOMP_2_P, and project “AIProcMat@N2020 - Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, reference NORTE-01-0145-FEDER- 000006, supported by NORTE 2020, under the Portugal 2020 Partnership Agreement, through FEDER, and Project Associate Laboratory LSRE-LCM - UID/EQU/50020/2019 - funded by national funds through FCT/MCTES (PIDDAC).info:eu-repo/semantics/publishedVersio

Wet peroxide oxidation of paracetamol using acid activated and Fe/Co-pillared clay catalysts prepared from natural clays

Many pharmaceuticals have been recently identified at trace levels worldwide in the aquatic environment. Among them, the highly consumed paracetamol (PCM), an analgesic and antipyretic drug, is largely being accumulated in the aquatic environment due to ine cient removal by conventional sewage treatment plants. This work deals with the treatment of PCM, used as a model pharmaceutical contaminant of emerging concern, by catalytic wet peroxide oxidation using clay-based materials as catalysts. The catalysts were prepared from natural clays, extracted from four di erent deposits using acid-activated treatment, calcination, and pillarization with Fe and Co. Pillared clays show the highest catalytic activity owing to the presence of metals, allowing to remove completely the PCM after 6 h under the following operating conditions: CPCM = 100 mg L1, CH2O2 = 472 mg L1, Ccat = 2.5 g L1, initial pH = 3.5 and T = 80 C. The prepared materials presented high stability since leached iron was measured at the end of reaction and found to be lower than 0.1 mg L1.This work is a result of the Project “AIProcMat@N2020—Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, with the reference NORTE-01-0145-FEDER-000006, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF); the Associate Laboratory LSRE-LCM—UID/EQU/50020/2019—funded by national funds through FCT/MCTES (PIDDAC); and CIMO (UID/AGR/00690/2019) through FEDER under Program PT2020.info:eu-repo/semantics/publishedVersio

Performance and modeling of Ni(II) adsorption from low concentrated wastewater on carbon microspheres prepared from tangerine peels by FeCl3-assisted hydrothermal carbonization

The presence of heavy metals in the environment as a consequence of human activity is an issue that has caught the attention of researchers to find wastewater treatment solutions, such as adsorption. In this work, hydrochars and activated carbon microspheres are prepared from tangerine peels as carbon precursor and FeCl3 as activating and structure-directing agent in the hydrothermal carbonization, allowing to obtain hydrochar microspheres ranging from 50 to 3615 nm. In addition, a pyrochar was prepared by pyrolysis of the same precursor. The activated carbon shows the highest surface area (SBET up to 287 m2 g–1), but the basicity of the pyrochar (1.83 mmol g 1, SBET = 104 m2 g–1) was determinant in the adsorption of Ni, being considered the carbon-based material with the highest uptake capacity of Ni. Isotherm and kinetic adsorption of Ni on the most representative activated carbon microsphere, pyrochar and hydrochar microsphere are assessed by 10 and 7 models, respectively.The authors are grateful to the FCT (Foundation for Science and Technology, Portugal) and FEDER (European Regional Development Fund) under Programme PT2020 for financial support to CIMO (UIDB/00690/2020). We would also like to thank the scientific collaboration under Base- UIDB/50020/2020 and Programmatic- UIDP/50020/2020 funding of LSRE-LCM, and LA/P/0045/2020 funding of ALiCE, funded by national funds through FCT and MCTES (Ministério da Ciência, Tecnologia e Ensino Superior, Portugal) by PIDDAC (Programa de Investimentos e Despesas de Desenvolvimento da Administraç˜ao Central, Portugal). Fernanda F. Roman and Adriano dos Santos Silva acknowledge the national funding by FCT and MIT (Massachusetts Institute of Technology, USA), and the ESF (European Social Fund) for individual research grants with reference numbers of SFRH/BD/143224/2019 and SFRH/BD/151346/2021, respectively.info:eu-repo/semantics/publishedVersio

Assisted hydrothermal carbonization of agroindustrial byproducts as effective step in the production of activated carbon catalysts for wet peroxide oxidation of micro-pollutants

This work deals with the valorisation of bagasse of sugarcane – BC, bagasse of malt – BM and seed of chia – SC, through its transformation into pyrochars, hydrochars and activated carbons (ACs) by pyrolysis, hydrothermal carbonization (HTC) and sequential HTC and pyrolysis, respectively. The HTC process was carried out in the presence of H2O, FeCl3 and H2SO4 solutions. The materials resulting by HTC in the presence of FeCl3 revealed the highest burn-off, but the contents of carbon released into the liquid phase, measured as total organic carbon, and to the gaseous phase, determined by carbon balance, depend strongly on the carbon precursor. In this sense, BC generates more volatile organic compounds (up to 34% of the initial carbon content), followed by BM (< 15%) and SC (< 5%) in their HTC and pyrolysis (70%). The pyrochars, hydrochars and ACs prepared from BC also show the highest specific surface areas (SBET < 447 m2⋅g-1) when compared to the specific surface areas of the materials prepared from BM and SC. The carbon-based materials prepared with FeCl3 show the highest catalytic activity, but iron leaching into solution is observed. On the other hand, the materials prepared with H2SO4 show high activity, enabling its application in successive cycles and the complete degradation of caffeine in concentrations ranging from 1 to 100 mg⋅L-1, after 5–60 min of reaction.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER (Fundo Europeu de Desenvolvimento Regional) under Programme PT2020 for financial support to CIMO (UIDB/00690/2020). Fernanda Fontana Roman also thanks to the FCT for the individual research grant SFRH/BD/143224/2019.info:eu-repo/semantics/publishedVersio

Contamination of staphylococcus aureus in the production lines of a Portuguese fermented sausage (linguiça)

Linguiça is a Portuguese dry-fermented sausage, which has been found to harbour food-borne pathogens in the past. Hence, the objective of this study was to investigate the levels of total viable counts (TVC), Enterobacteriaceae, and S. aureus at the key production stages of linguiça by depicting their changes using principal component analysis. Unlike Enterobacteriaceae counts, which decreased from raw meat to final product, S. aureus increased significantly in the meats throughout processing. While Enterobacteriaceae was very sensitive to the decrease in water activity, S. aureus remained viable and developed during fermentation. The presence of S. aureus at all stages should prompt industries to reinforce good hygiene practices in the processing of linguiça.Esta investigación se realizó dentro del proyecto PTDC/AGR-TEC/3107/2012, financiado por la Fundación Portuguesa de Ciencia y Tecnología (FCT)/Fondos Europeos de Desarrollo Regional (FEDER). La Dra. Gonzales-Barron agradece el apoyo financiero provisto por la FCT a través del programa Investigador Fellowship (IF 00570)info:eu-repo/semantics/publishedVersio