Removal of tiemonium methylsulfate, from aqueous solutions using activated carbon prepared from date stones

International audienceThe retention of a pharmaceutical compound, tiemonium methylsulfate (TIM), from aqueous solutions by adsorption onto activated carbon prepared from date stones (AC–DS) was investigated. Physical and chemical characteristics of this material were also determined. Results showed that pH 8 was optimal for TIM adsorption. Among the kinetic models considered, the pseudo-second-order model was the most appropriate to describe experimental data. Regarding adsorption isotherms, it was shown that the Sips model accurately describe the sorption of TIM onto AC–DS with a correlation factor R2 > 0.98. The adsorption capacity of AC–DS was found to be 42.2 mg g−1 at 10°C and 60.5 mg g−1 at 25°C, confirming its efficiency for the removal of this compound from aqueous solutions. The values of ΔG0 and ΔH0 confirmed that the adsorption of TIM onto AC–DS was spontaneous and endothermic in nature and hence more effective at high temperatures. An irregular increase in the randomness was suggested at the AC–DS solution interface during the adsorption process for positive values of ΔS0

Local Materials and Solid Waste (Sawdust) Valorization in the Treatment of Industrial Synthetic Water Field

International audienceThis work dealt with a dual environmental aspect: on the one hand, the valorization of natural by-products (sawdust and dune sand), and, on the other hand, the assessment of the purification efficiency of a bilayer of the two by-products. The effectiveness was evaluated through the monitoring of some parameters, namely, paranitrophenol concentration, BOD5, and COD. Promising results were obtained, and hence further works are in progress regarding the application of this process to other pollutants present in wastewater. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG

Removal of tiemonium methylsulfate, from aqueous solutions using activated carbon prepared from date stones

International audienceThe retention of a pharmaceutical compound, tiemonium methylsulfate (TIM), from aqueous solutions by adsorption onto activated carbon prepared from date stones (AC–DS) was investigated. Physical and chemical characteristics of this material were also determined. Results showed that pH 8 was optimal for TIM adsorption. Among the kinetic models considered, the pseudo-second-order model was the most appropriate to describe experimental data. Regarding adsorption isotherms, it was shown that the Sips model accurately describe the sorption of TIM onto AC–DS with a correlation factor R2 > 0.98. The adsorption capacity of AC–DS was found to be 42.2 mg g−1 at 10°C and 60.5 mg g−1 at 25°C, confirming its efficiency for the removal of this compound from aqueous solutions. The values of ΔG0 and ΔH0 confirmed that the adsorption of TIM onto AC–DS was spontaneous and endothermic in nature and hence more effective at high temperatures. An irregular increase in the randomness was suggested at the AC–DS solution interface during the adsorption process for positive values of ΔS0

Agregação de valor à resíduo agroindustrial: remoção de fenol utilizando adsorvente preparado a partir de casca de amendoim

Este trabalho teve como objetivo avaliar a eficiência do carvão ativado com CO2 (CA) produzido a partir da casca de amendoim como adsorvente para remoção de fenol em solução aquosa (100-300 mg.L-1). A caracterização do CA foi realizada pelos métodos de BET, DRX, TGA, FT-IR e pHpcz, houve a caracterização da casca de amendoim (CS) para fins de comparação. Avaliou-se a influência do pH inicial da solução e a dosagem do adsorvente (D.A.). As condições de trabalho foram definidas com o auxílio de um planejamento fatorial 23 (PF) avaliando a influência das variáveis: D.A., granulometria (G.) e velocidade de agitação (V.A.) sobre o processo adsortivo, tendo como resposta a capacidade adsortiva q (mg.g-1). Com base nos resultados do PF foram realizados estudos cinéticos e de equilíbrio de adsorção. O carvão foi classificado como mesoporoso e predominantemente amorfo. Na TGA foi observada maior estabilidade do material após a ativação. Nos espectros de FT-IR foram identificadas bandas referentes a grupos hidroxilas, carboxílicos e ésteres. O pHpcz foi 10,4 possibilitando a utilização das soluções fenólicas em pH natural da solução. No PF, o maior q foi obtido para o nível 4 g.L-1, G. 0,090 mm e 300 rpm, condição adotada nos estudos cinéticos e de equilíbrio. A evolução cinética foi rápida até 120 minutos, atingindo o equilíbrio em torno de 480 minutos. O modelo pseudo n ordem foi o que melhor se ajustou aos dados experimentais e foi constatado que o processo é controlado por mais de uma etapa, incluindo difusão intrapartícula. No estudo do equilíbrio os modelos que melhor se ajustaram aos dados experimentais foram os de Fritz-Schlunder e Redlich-Peterson apresentando qmax de 29,01 À 0,96 mg.g-1. Os resultados demonstraram o potencial técnico do carvão em estudo para remoção de fenol presente em solução aquosaPalavras-chave: ativação física, efluente industrial, resíduo agroindustrial