Removal of diclofenac sodium from aqueous solution by Isabel grape bagasse

Abstract

International audienceThe aim of the present work was to evaluate the morphologic and chemical characteristics of Isabel grape (Vitis labrusca x Vitis vinifera) bagasse and to describe the adsorption of diclofenac sodium (DCF) from aqueous solutions by this biomass. Grape bagasse was constituted mainly of particles with heterogeneous shapes and sizes, and it exhibited a macroporous structure and a low specific surface area (∼ 2 m2 g-1). The adsorbent material was also rich in oxygenated functional groups, especially -OH, and required an acidic pH to neutralize its surface. With respect to the adsorption of DCF, the percentage removal did not appear to depend on the initial concentration of the pharmaceutical. A pseudo-second-order kinetic model described the rate-controlling step, and the adsorption isotherms were well fitted by the Freundlich model. Concerning the thermodynamic data, the results showed that the adsorption of DCF onto grape bagasse occurred via an exothermic process accompanied by a decrease in the randomness at the solid/solution interface. Furthermore, the removal percentages of DCF ranged from 16.4 to 22.8%

Effect of temperature and soil pH on the sorption of ibuprofen in agricultural soil

“…The values of ΔG ranged from +0.21 to +1.16 kJ/mol and increased with temperature, indicating that the sorption of ibuprofen in the soil was not spontaneous. According to Antunes et al (2012), this may be due to repulsion between the soil surface and ibuprofen that are both negatively charged at soil pH of 5.76. Positive values of ΔG were also found for the soil sorption of negatively charged pharmaceutical, sulfisoxazole (Maszkowska et al 2014).…”

Removal of Pharmaceuticals from Wastewater by Intermittent Electrocoagulation

“…For CBZ and AMX, degradation efficiencies increase at an increasing initial concentration (Figure 4). This can be attributed to the increase of concentration gradient which means a stronger driving force to overcome all mass transfer resistances of solutes between the aqueous and the solid phase [67,68]. As a result, there is better adsorption to electrocoagulants.…”

Estudo Cinético Da Remoção De Diclofenaco De Sódio Em Solução Aquosa Por Adsorção Em Argila Organofílica Spectrogel

“…Pode-se sugerir, então, que o modelo de pseudossegunda ordem melhor descreve os resultados experimentais em todas as concentrações avaliadas, indicando que a quimissorção ocorre no processo de adsorção do diclofenaco de sódio pela argila Spectrogel tipo C. Esse resultado é esperado e condizente com os encontrados na literatura (Luna et al, 2017;Antunes et al, 2012). As constantes cinéticas k 1 e k 2 são maiores quanto menor for a concentração da solução, indicando que quanto menor a concentração inicial, mais rapidamente irá acontecer a adsorção.…”