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The production of added-value chemicals via pyrolysis of plastic wastes, such as those from electrical and electronic equipment (WEEE), needs addressing their usual contamination with halogens (mainly Br and Cl). This work compares the conversion via pyrolysis and hydropyrolysis of a real WEEE plastic, having a complex composition, in two different reactor configurations: down-flow (DF) and up-flow (UF). Likewise, the effects of incorporating a Pd/Al2O3 catalyst and using two different pressures (1 and 6 bar) have been assessed. With the DF mode, pyrolysis at 1 bar leads to an oil yield above 80 wt% and a total halogen content of about 600 ppm (vs 1600 ppm in the water-washed WEEE plastic). Under DF catalytic hydropyrolysis at 6 bar, this high oil yield is maintained while its dehalogenation degree is improved (142 ppm). Operating with the up-flow configuration, under 6 bar and H2 presence, leads to some reduction in the oil yield (about 70 wt%) but significantly decreases the oil halogen content (55 ppm Cl and total elimination of Br). These results have been related to the slower pyrolysis and longer residence time in the thermal zone of the UF configuration, which favours the halogen-trapping effect of the char fraction, and the pressure-enhanced hydrodehalogenation activity of the catalyst. This study highlights the environmental benefits of the proposed process, emphasizing the lower halogen content in the resulting oils and promoting a more sustainable approach to plastic waste valorisation.
RESUMO
BACKGROUND: This study describes the prevalence of hypophosphatemia, hypokalemia, and/or hypomagnesemia and resulting electrolyte supplementation during refeeding in severely malnourished youths hospitalized for restrictive eating disorders. METHODS: Hospitalized patients between 11-26y (N = 81) at < 75% treatment goal weight (TGW) were assessed through retrospective chart review. Outcomes were compared between participants < 70% TGW and those 70-75% TGW. Nutritional rehabilitation started at 1750 kcals/day and advanced by 500 kcal every other day until target intake was achieved. Associations between %TGW on admission; hypophosphatemia, hypokalemia, and/or hypomagnesemia; and electrolyte supplementation were examined. RESULTS: Of the 24 (29.6%) participants with hypophosphatemia, hypokalemia, and/or hypomagnesemia, 7 (8.6%) received supplementation; the remainder corrected without supplementation. Participants < 70% TGW did not differ from those 70-75% TGW on rates of these conditions or need for supplementation. CONCLUSIONS: Hospital-based nutritional rehabilitation did not confer increased rates of hypophosphatemia, hypokalemia, and/or hypomagnesemia or need for electrolyte supplementation in patients < 70% TGW compared to those 70-75% TGW. While additional research is needed to establish clinical practice guidelines on electrolyte management in this population, our findings suggest that nutritional rehabilitation may be reasonably undertaken without prophylactic electrolyte supplementation, even in patients < 70% TGW.
Identifying safe management methods for nutritional rehabilitation among severely malnourished hospitalized adolescents and young adults with restrictive eating disorders can expedite discharge planning and improve treatment outcomes. In contrast to past studies on inpatient nutritional rehabilitation, this study describes the prevalence and management of multiple-electrolyte disturbance (hypophosphatemia, hypokalemia, and/or hypomagnesemia) during refeeding among hospitalized severely malnourished youths with restrictive eating disorders. We found that in this population, with experienced, close medical supervision, nutritional rehabilitation may be reasonably undertaken without prophylactic electrolyte supplementation, even in patients < 70% goal treatment weight. These findings can inform hospital-based refeeding protocols for adolescents and young adults with restrictive eating disorders, where the practice around prophylactic supplementation is variable.
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The synthesis of ZSM-5 zeolites by hydrothermal crystallization of protozeolitic nanounits functionalized with amphiphilic organosilanes of different chain length (Cn-N(CH3)2-(CH2)3-Si-(OCH3)3, n = 10, 14, 18 and 22) has been investigated. Well-developed dendritic nanoarchitectures were achieved when using C14 and C18 organosilanes, exhibiting a radial and branched pattern of zeolitic nanounits aggregates. In contrast, although C10 and C22 organosilanes led to materials with hierarchical porosity, they lack of dendritic features. These differences have been linked to the formation of an amorphous mesophase at the gel preparation stage for the C14 and C18 samples, in which the surfactant micelles are covalently connected with the protozeolitic nanounits through siloxane bonds. The presence of the dendritic nanostructure positively impacts both the textural and catalytic properties of ZSM-5 zeolite. Thus, ZSM-5 (C14) and ZSM-5 (C18) samples exhibit the largest contribution of mesoporosity in terms of both surface area and pore volume. On the other hand, when tested as catalysts in the aldol condensation of furfural with cyclopentanone, which is an interesting reaction for the production of sustainable jet fuels, the highest catalytic activity is attained over the dendritic ZSM-5 materials due to their remarkable accessibility and balanced Brønsted/Lewis acidity.