Exceptional performance of Fe@carbon-rich nanoparticles prepared via hydrothermal carbonization of oil mill wastes for H2S removal.

Carbon-encapsulated iron oxide nanoparticles (CE-nFe) have been obtained from an industrial waste (oil mill wastewater-OMW, as a carbonaceous source), and using iron sulfate as metallic precursor. In an initial step, the hydrochar obtained has been thermally activated under an inert atmosphere at three different temperatures (600 °C, 800 °C and 1000 °C). The thermal treatment promotes the development of core-shell nanoparticles, with an inner core of α-Fe/Fe3O4, surrounded by a well-defined graphite shell. Temperatures above 800 °C are needed to promote the graphitization of the carbonaceous species, a process promoted by iron nanoparticles through the dissolution, diffusion and growth of the carbon nanostructures on the outer shell. Breakthrough column tests show that CE-nFe exhibit an exceptional performance for H2S removal with a breakthrough capacity larger than 0.5-0.6 g H2S/gcatalyst after 3 days experiment. Experimental results anticipate the crucial role of humidity and oxygen in the adsorption/catalytic performance. Compared to some commercial samples, these results constitute a three-fold increase in the catalytic performance under similar experimental conditions.

Pollutant content in marine debris and characterization by thermal decomposition.

Marine debris (MDs) produces a wide variety of negative environmental, economic, safety, health and cultural impacts. Most marine litter has a very low decomposition rate (plastics), leading to a gradual accumulation in the coastal and marine environment. Characterization of the MDs has been done in terms of their pollutant content: PAHs, ClBzs, ClPhs, BrPhs, PCDD/Fs and PCBs. The results show that MDs is not a very contaminated waste. Also, thermal decomposition of MDs materials has been studied in a thermobalance at different atmospheres and heating rates. Below 400-500K, the atmosphere does not affect the thermal degradation of the mentioned waste. However, at temperatures between 500 and 800K the presence of oxygen accelerates the decomposition. Also, a kinetic model is proposed for the combustion of the MDs, and the decomposition is compared with that of their main constituents, i.e., polyethylene (PE), polystyrene (PS), polypropylene (PP), nylon and polyethylene-terephthalate (PET).

[Primary peptic ulcer in childhood: apropos of 16 cases]. / Ulcera péptica primaria en la infancia: a propósito de 16 casos.

We report a retrospective review of primary peptic ulcer disease in 16 children, 8 boys and 8 girls between 2 and 14 years of age, seen at our hospital over a 4 years and 4 months period. Endoscopy was realized in all children and revealed 7 duodenal ulcers (DU) and 11 gastric ulcers (GU) (two patients had both locations). At the initial diagnosis 5 patients were less than 6 years old with a ratio GU/DU of 4:1; in the other patients this ratio was 1:1. In children with duodenal ulcer 56.5% of them had positive family history. The commonest presenting symptoms were abdominal pain (87.5%) and acute gastrointestinal bleeding (68.7%). The follow-up period ranged from 2 to 52 months; in 13 cases follow-up was more than 1 year. Four patients (3 DU and 1 GU) older than 6 years recurred.