Darlyson Tavares Guimarães, Liana Maria Ramos Mendes, Luiz Bruno de Sousa Sabino, Edy Sousa de Brito, Enrique Vilarrasa-García, Enrique Rodríguez-Castellón, Juan Antonio Cecilia, Ivanildo José da Silva Junior
{"title":"Partial Purification of Anthocyanins (Brassica oleracea var. Rubra) from Purple Cabbage Using Natural and Modified Clays as Adsorbent","authors":"Darlyson Tavares Guimarães, Liana Maria Ramos Mendes, Luiz Bruno de Sousa Sabino, Edy Sousa de Brito, Enrique Vilarrasa-García, Enrique Rodríguez-Castellón, Juan Antonio Cecilia, Ivanildo José da Silva Junior","doi":"10.1155/2023/2724122","DOIUrl":"https://doi.org/10.1155/2023/2724122","url":null,"abstract":"This research is aimed at evaluating strategies for the adsorption and recovery of anthocyanins present in purple cabbage using natural and modified clays as adsorbent. In the batch adsorption experiments, the anthocyanin extracts were put in contact with the adsorbents, and different parameters were evaluated to determine the best conditions for their adsorption and recovery. It was noted that the highest levels of adsorption (28.0 mg g<sup>-1</sup>) occurred using a porous clay heterostructure (PCH) material as adsorbent, with a mass of 25 mg and 120 min of contact. Under the same conditions, the sepiolite only presented an adsorption capacity of 14.0 mg g<sup>-1</sup>. The desorption results showed that the 60% methanolic solution recovered 60% of the anthocyanins adsorbed on PCH, while the 80% ethanolic solution recovered 35% of those adsorbed on sepiolite. The eluted anthocyanin solutions showed a 98% lower sugar concentration than the crude extract, indicating the low affinity of the adsorbents for sugars. Six types of acylated cyanidins were identified via UPLC-QToF-MSE in the extract, and it was confirmed from the FTIR analyses that the highest affinity of the clays occurred with the anthocyanins that presented more organic acid in their structure. The results show that PCH and sepiolite have high selectivity for anthocyanins and low affinity for the sugars present in the plant extract, facilitating the process of partial purification and application of these pigments.","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":"15 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138579578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dual Role of Fe2+ in the Galena Flotation and Influence on Selective Separation","authors":"Bo Yang, Xiao Wang, Xian Xie, Zixuan Yang","doi":"10.1155/2023/1660716","DOIUrl":"https://doi.org/10.1155/2023/1660716","url":null,"abstract":"Fe ions, as one of the unavoidable metal ions, are present in flotation pulp as ferric and ferrous species, and the effect of ferric species on the flotation behavior of sulfide minerals has been widely discussed in the above literatures. However, the effect of ferrous species has rarely been noticed. In this paper, the effect of ferrous species on the flotation behavior and surface characteristics of galena was investigated by using microflotation, zeta potential measurements, X-ray photoelectron spectrometer (XPS) analysis, and density functional theory (DFT) calculations. Microflotation tests indicated that the flotation recovery of galena with potassium butyl xanthate (KBX) as collector was significantly decreased with the addition of Fe<sup>2+</sup> in the pulp, and the recovery was further decreased with increasing dosage of Fe<sup>2+</sup>. In addition, the finer the galena particles, the greater the decrease in flotation recovery. Zeta potential analysis illustrated that the isoelectric point (IEP) was shifted from 4.4 to 5.8 due to the adsorption of ferrous hydroxyl complexes on the galena surface and the zeta potential. XPS surface analysis suggested that the surface oxidation of galena was alleviated by the consumption of O<sub>2</sub> in the pulp, which reduced the adsorption of the collector KBX on and the oxidation of xanthates to dixanthogens. Density functional theory (DFT) calculations confirmed that the ferrous hydroxyl complex FeOH<sup>+</sup> could be adsorbed on the galena surface by interactions between Fe and S atoms.","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":"21 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138510182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Investigation of the Zeta Adsorption Model and Gas-Solid Adsorption Phase Transition Mechanism Using Statistical Mechanics at Gas-Solid Interfaces","authors":"Di Zhang","doi":"10.1155/2023/8899160","DOIUrl":"https://doi.org/10.1155/2023/8899160","url":null,"abstract":"This review examines the significance of the zeta adsorption model in physics and its integration with statistical mechanics within the field of interface adsorption. Through a comprehensive analysis of existing research, this study presents the collective findings and insights derived from the reviewed literature. The zeta adsorption model, proposed by Ward, has gained recognition for its seamless extension into the thermal disequilibrium region without encountering singularities. By incorporating principles from quantum mechanics and statistical thermodynamics, this model offers fresh perspectives on the adsorption of gas molecules on solid surfaces. Notably, it demonstrates enhanced accuracy in describing the adsorption performance of mesoporous materials and nanomaterial surfaces, surpassing the limitations of traditional models such as the BET isotherm. Additionally, this review explores the behavior of cluster formation under varying temperature and pressure conditions. It highlights the correlation between increasing pressure ratios and the decreased availability of empty adsorption sites, resulting in the formation of larger clusters within the adsorbate. Ultimately, this process leads to a transition from adsorption to condensation, where the liquid phase wets the solid surface. Moreover, the zeta adsorption model provides a solid theoretical foundation for understanding crucial aspects of gas-solid interface adsorption. It enables the determination of the distribution of adsorbate clusters on gas-solid interfaces, facilitates the identification of wetting pressure ratios during phase transitions, and allows for the calculation of solid surface tension under conditions of zero adsorption. Noteworthy parameters such as the bonding strength (<i>β</i>) between the solid surface and adsorbed atoms significantly influence the overall strength of the solid-fluid interaction. Furthermore, the phenomenon of surface subcooling, which necessitates sufficient energy for the transformation from adsorbed vapor to condensate liquid, plays a pivotal role in studying interface phase transitions. Additionally, this review investigates the thermodynamic stability of the adsorbate through an analysis of molar latent heat. It reveals that beyond a critical adsorbate coverage, the formation of critical-sized clusters and the ensuing interactions among these components render the adsorbate unstable. This instability prompts a transition from the interface to a liquid phase, followed by subsequent adsorption onto the surface. In summary, this literature review highlights the significant contributions of the zeta adsorption model to the field of physics, particularly in the context of interface adsorption. It serves as a valuable tool for studying various materials and cluster formation, thanks to its seamless extension into the thermal disequilibrium region and its incorporation of principles from quantum mechanics and statistical thermodynamics. By presenting","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":"23 6","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138510121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sulphuric Acid-Modified Coal Fly Ash for the Removal of Rhodamine B Dye from Water Environment: Isotherm, Kinetics, and Thermodynamic Studies","authors":"G. Bharath Balji, P. Senthil Kumar","doi":"10.1155/2023/2808794","DOIUrl":"https://doi.org/10.1155/2023/2808794","url":null,"abstract":"Among the wide variety of dyes present in the environment, cationic dyes are more toxic and have complex structure. The adsorption process of rhodamine B dye was successfully carried out by sulphuric acid-treated inexpensive modified fly ash (MFA) adsorbent via batch experiments. The nature of the adsorbent was characterized by techniques, namely, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The maximum removal efficiency of RhB dye was found to be 99.78% by using 0.5 g of adsorbent dosage in 50 mg/L of dye concentration. The SEM images displayed the porous nature of the adsorbent where the EDS analysis displays the elemental compositions present in the adsorbent. XRD pattern shows the crystallinity nature of the adsorbent. Among the batch study parameters, effect of pH plays an important role in the adsorption process. The pH of 4 was found to be an ideal setting for the efficient removal of the dye RhB. The preferable elimination ability was found by keeping the dosage at 5 g/L, contact time 120 min, and dye concentration at 50 mg/L. Adsorption capacity was found to be 36.36 mg/g. This shows the ability of the MFA for the removal of wastewater contaminants. This adsorption process is well suited for the Freundlich isotherm, which displaces the process as a multilayer adsorption. Studies in kinetics and thermodynamics demonstrate that the process was well suited for its exothermic nature and pseudo-second-order. Thermal regeneration studies were carried out, and the adsorbent was effectively recycled and utilized up to four more times with minimal loses in its effectiveness. Therefore, from these obtained results, it is clear that the MFA is an effective adsorbent for the effective removal of dyes from wastewater.","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":"41 15","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135041969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enhanced Adsorption of Rose Bengal Dye from Aqueous Solution Using NaOH Activated Hydrochar Derived from Corncob Waste","authors":"R. Sivaranjanee, P. Senthil Kumar","doi":"10.1155/2023/6695350","DOIUrl":"https://doi.org/10.1155/2023/6695350","url":null,"abstract":"A potential approach to the preparation of affordable activated hydrochar is the hydrothermal carbonization of biomass wastes. In this study, hydrochar was made by hydrothermally carbonizing corncob wastes and then activating them with sodium hydroxide (NaOH). According to the findings, the adsorption capabilities of hydrochar generated at prolonged retention durations, lesser liquid-to-solid ratios, and elevated temperatures were considerably greater. The hydrochars were then analyzed utilizing a variety of characterization methods, and batch tests involving the sorption of rose bengal dye were carried out under a variety of conditions. According to the findings, activated hydrochar has a specific surface area of 12.794 m2/g. In order to better understand and characterize the process of rose bengal dye adsorption, sorption kinetics, and sorption equilibrium onto the produced hydrochars, sorption kinetics and isotherms were further examined through experimental data fitting. The NaOH-activated hydrochar’s adsorption capacity was 799.9 mg/g, respectively. The objective of this research was to assess the viability of using NaOH-activated hydrochar derived from corncobs as an economical and efficient sorbent for eliminating anionic dyes like rose bengal from aqueous solutions. Additionally, the study sought to investigate how various factors influence its sorption capabilities and to provide insights into the adsorption process through kinetic and isotherm analyses.","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":" 39","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135340806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Retracted: Simple Preparation of the CuO•Fe3O4/Silica Composite from Rice Husk for Enhancing Fenton-Like Catalytic Degradation of Tartrazine in a Wide pH Range","authors":"Adsorption Science and Technology","doi":"10.1155/2023/9810765","DOIUrl":"https://doi.org/10.1155/2023/9810765","url":null,"abstract":"<jats:p />","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135271420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}