3 resultados para 4 hydroxybenzoic acid
em Repositório Científico da Universidade de Évora - Portugal
Resumo:
In this work the maximum carbon dioxide adsorption capacity of carbon aerogels, obtained by a sol-gel process using 2,4-dihydroxybenzoic acid/formaldehyde (DHBAF) and resorcinol/formaldehyde (RF) as precursors, was studied. The effect of increasing the temperature of carbonization and physical activation of the samples DHBAF was also studied. The results showed that the maximum adsorption capacity is favoured at lower temperatures, adsorption and desorption are rapid and the performance is maintained over several cycles of CO2 adsorption/desorption. A comparison with samples of commercial carbons was also made and it was concluded that carbon aerogels exhibit a behaviour comparable or superior to that obtained for the commercial carbons studied.
Resumo:
A series of activated carbon was produced from particleboard and medium-density fibreboard monoliths, which are waste originated from the industry, and then characterized and evaluated for potential application for phenoxyacetic acids removals, such 2,4-dichlorophenoxyacetic acid (2,4-D), 2-methyl-4-chlorophenoxy acetic acid (MCPA) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron), from the liquid phase. All AC retain the shape of the precursor, and displays a microporous structure well-developed, reaching 0.58 cm 3 g -1. The adsorption isotherms for three pesticides were obtained in the optimal conditions and the AC with high superficial area and micropore volume exhibited better performance, allowing to state that, this AC could be a great substitute of those habitually used for this purpose. The pesticides adsorption data were linearized using the Langmuir and Freundlich equation, being the first a very good fit to the experimental data.
Resumo:
A series of activated carbon was produced from particleboard and medium-density fibreboard monoliths, which are waste originated from the industry, and then characterized and evaluated for potential application for phenoxyacetic acids removals, such 2,4-dichlorophenoxyacetic acid (2,4-D), 2-methyl-4-chlorophenoxy acetic acid (MCPA) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron), from the liquid phase. All AC retain the shape of the precursor, and displays a microporous structure well-developed, reaching 0.58 cm 3 g -1. The adsorption isotherms for three pesticides were obtained in the optimal conditions and the AC with high superficial area and micropore volume exhibited better performance, allowing to state that, this AC could be a great substitute of those habitually used for this purpose. The pesticides adsorption data were linearized using the Langmuir and Freundlich equation, being the first a very good fit to the experimental data.