In this work, malachite green dye was removed from an aqueous effluent using acerola seed as an adsorbent. The adsorbent was characterized by Fourier transform infrared (FTIR), X-ray diffraction, zero charge potential, and acid group concentration techniques. The findings revealed that the adsorbent has a characteristic composition of lignocellulosic materials, as described by the FTIR data, besides having a pH-PZC of 3.5 and a concentration of acid groups of 0.2313 mmol g−1. The central composite design was used for batch experiments, and the effects of three variables were analysed. The optimum conditions (pH, particle size, and adsorbent mass) were 10.0, 600 μm, and 0.8 g, respectively, for 97.52% dye removal. Redlich–Peterson isotherm fitted well to the experimental data (R2 = 0.997 and root-mean-square error (RMSE) = 1.168). From the Langmuir isotherm, the maximum adsorption capacity obtained for dye was 103.50 mg g−1. As for the adsorption kinetics, it was found that the pseudo-second-order model sufficiently describes the experimental data (R2 = 0.999 and RMSE = 0.018). Thus, the acerola seed has excellent properties as an adsorbent, demonstrating a remarkable performance and a great capacity to be used in the treatment of aqueous effluents contaminated by dyes.
Abstract-Proposals, and the BET area an increase of five times in the pore diameter, with the addition of the reagent to obtain higher porosity. It follows that the process of synthesis of SAPO-5 and SAPO-5M shows to be effective for increasing the area and pore volume and with this addition of the reagent to obtain the mesoporosity, did not alter the crystallinity nor the structure of the material.
<p>Activated carbons are organic materials characterized by the ability to adsorb impurities from fluids, being considerably used industrially. In the oil extraction industry, the water produced (WP) is an undesired effluent that, due to its toxic and contaminating characteristics related to its high total oil and grease (TOG), needs adequate treatment before it is directed to reuse or disposal. In this sense, activated carbon is shown as a viable alternative for the process of removing contaminants. In the present study, several tests were carried out with samples of activated carbon treated with hydrochloric acid in two samples of produced water, in order to determine the general efficiency of the adsorbent and the ideal proportions and exposure periods for an effective treatment. The percentage reduction rates reached approximately 100% and 75% for the two water samples from the different wells from which they were drawn. The results show the efficiency of the adsorptive process used to reduce the TOG content of the produced water.</p>
The stability of shales rich in clay is deeply affected by its complex physical and chemical interactions with drilling fluids. Thus, these rocks with a high content of clay have shown significant changes, such as swelling or expanding, when placed in contact with aqueous fluids due to the adsorption of polar molecules of water or hydrated ions dissolved inside . These changes may cause the collapse of the rock during the drilling with water-based drilling fluids. For a better understanding of the phenomenon of interaction between the rock and the drilling fluid, this study aims to analyze reactivity of shales from the Bacia do Araripe through its characterization. In order to do so, the shales were characterized by CEC, XRF, XRD and Foster swelling. The results indicated that the shales showed significant values of CEC, FRX composition close to that of smectite, and XRD pattern with characteristic peaks of smectite. Regarding the Foster swelling, the shale that presented the highest CEC (F-IP) also presented the highest value of swelling, indicating that the CEC can be applied as an indicative parameter of the reactivity.
As the water produced comes from the oil and gas industry, the by-product generated in greater quantity and given its potential to cause environmental impacts, several techniques have been proposed in order to attenuate the concentration of its contaminants, among which we highlight the process of adsorption. In this context, the objective of this work was to characterize and treat the water produced by the adsorption in a finite bath, using activated carbon from coconut (Cocos nucifera L. )as an adsorbent . The results of the characterization of the effluent present fairly high values for total hardness, chlorides, sodium and Chemical Oxygen Demand (COD). We also carried out the characterization of the activated carbon by XRD and BET techniques, in which the low crystallinity and the high surface area of the material were proved. Through a factorial experimental design 22 and taking into account the mass of the adsorbent and the time of contact with the effluent, it was verified that, when using 0.2 g of adsorbent to 100 ml of effluent by stirring for 6 hours, it was possible to obtain a 100% reduction in the COD present in the water produced, which represents the high efficiency of the treatment.
RESUMO -A redução do teor de enxofre na gasolina se apresenta como a melhor opção para se alcançar um ar e um meio ambiente mais limpos. Propostas têm aparecido visando à remoção desse elemento por intermédio dos processos de adsorção. Esse processo requer a utilização de adsorventes seletivos, com alta capacidade de adsorção do contaminante e regeneração dos mesmos. As peneiras moleculares vêm se mostrando como um excelente adsorvente, como é o caso do silicoaluminofosfato (SAPO). Elas apresentam grande área superficial específica, o que implica em uma estrutura altamente porosa. Assim, este trabalho tem como objetivo sintetizar SAPO-5, para obtenção de uma área superficial e diâmetro de poro maior, com adição de um reagente na síntese desse material. Para isso, foi realizada técnicas de caracterização, como DRX, EDX e BET. A área superficial teve um aumento de 19% na área BET, e no diâmetro do poro cerca de 63% com a adição do reagente para a obtenção de maior porosidade. Obteve-se um material altamente cristalino, com suas estruturas bastante ordenadas, com teores dos óxidos dos elementos característicos do SAPO-5.
<p>O aumento da geração de efluentes petrolíferos tóxicos exige cada vez mais tecnologias de tratamento eficientes, entre as quais se destacam os processos de oxidação, como o processo Fenton, devido à sua rápida e eficaz degradação de poluentes derivados do petróleo. Esse tratamento não é tão oneroso para a aplicação em escala industrial, as maiores despesas estão associadas à energia elétrica e aos reagentes. Neste sentido, utilizou-se um planejamento experimental com intuito de investigar a influência das concentrações de íons Fe<sup>2+</sup> e de H<sub>2</sub>O<sub>2</sub> sobre a remoção de óleos e graxas em água produzida. Para tanto se conduziu um planejamento fatorial (2<sup>2</sup>) com repetições no ponto central, totalizando sete ensaios. Os resultados obtidos mostraram que houve, em alguns ensaios, umas reduções significativas na concentração de óleos e graxas presentes no efluente, o que indica que a reação de Fenton pode ser utilizada como tratamento promissor para esse tipo de resíduo. A partir da análise estatística dos dados experimentais verificou-se que as concentrações de Fe<sup>2+</sup> e de H<sub>2</sub>O<sub>2</sub> bem como a interação entre esses dois fatores influenciam significativamente a eficiência de remoção, e que o modelo de 1ª ordem, sem curvatura, descreve bem o processo de tratamento (<em>R<sup>2</sup></em> = 0,9977).</p>
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.