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Environment International Feb 2020In recent years, graphene-based materials (GBMs) have been regarded as the core technology in diverse research fields. Consequently, the demand for large-scale synthesis... (Review)
Review
In recent years, graphene-based materials (GBMs) have been regarded as the core technology in diverse research fields. Consequently, the demand for large-scale synthesis of GBMs has been increasing continuously for various fields of industry. These materials have become a competitive adsorbent for the removal of environmental pollutants with improved adsorption capacity and cost effectiveness through hybridization or fabrication of various functionalities on their large surface. In particular, their applicability opens up new avenues for the adsorptive removal of volatile organic compounds (VOCs) (e.g., through the build-up of efficient air purification systems). This review explored the basic knowledge and synthesis approaches for GBMs and their performances as adsorbent for VOC removal. Moreover, the mechanisms associated with the VOC removal were explained in detail. The performance of GBMs has also been evaluated along with their present limitations and future perspectives.
Topics: Adsorption; Environmental Pollutants; Graphite; Nanostructures; Volatile Organic Compounds
PubMed: 31881425
DOI: 10.1016/j.envint.2019.105356 -
Chemistry, An Asian Journal Feb 2022There is an increasing level of various pollutants and their persistence in aquatic environments. The improper use of antibiotics and their inefficient metabolism in... (Review)
Review
There is an increasing level of various pollutants and their persistence in aquatic environments. The improper use of antibiotics and their inefficient metabolism in organisms result in their release into aquatic environments. Antibiotic abuse has led to hazardous effects on human health. Thereby, efficient removal of pharmaceuticals, particularly antibiotics, from wastewater and contaminated water bodies is greatly interested in international research communities. Metal-organic framework (MOF) materials, as a hybrid group of material containing metallic center and organic linkers, offer a porous structure that is highly efficient for removing different pollutants from contaminated water and wastewater streams. This article aims to review the recent advancement in using MOF-based adsorbents and catalysts for the removal of pharmaceuticals, especially antibiotics, from polluted water. Applying MOFs-based structures for removing antibiotics using photocatalytic removal and adsorptive removal techniques will be discussed and evaluated in this review paper. Various MOF-based materials such as functionalized MOFs, MOF-based composites, magnetic MOF-based composites, MOFs templated-metal oxide catalysts for removing pharmaceuticals, personal care products, and antibiotics from contaminated aqueous media are discussed. Furthermore, effective operational parameters on the adsorption, adsorption mechanisms, adsorption isotherms, and thermodynamic parameters are explained and discussed. Finally, in the concluding remarks, the challenges and future outlooks of using MOFs-based adsorbents and catalysts for removing antibiotics are summarized.
Topics: Adsorption; Anti-Bacterial Agents; Humans; Metal-Organic Frameworks; Pharmaceutical Preparations; Water Purification
PubMed: 34941022
DOI: 10.1002/asia.202101105 -
Journal of Environmental Management Aug 2019The synthesis and application of efficient materials for remediation of environmental contaminants from water is an emerging area of research. Graphene has received... (Review)
Review
The synthesis and application of efficient materials for remediation of environmental contaminants from water is an emerging area of research. Graphene has received tremendous attention in various fields due to its exceptional properties. Graphene and its derivatives have also been extensively explored for the adsorptive removal of pollutants from water. The recent trends are inclined toward functionalization of graphene-based materials to get the advantage of their improved properties. The functionalized graphene materials are efficient due to their enhanced properties resulting from synergistic effects. This article reviews the synthesis and application of graphene-based adsorbents for the removal of organic pollutants from water. A critical account is provided on synthesis methods, applications, adsorption mechanisms, the figure of merits, and removal performances. The accomplishments, limitations, challenges, and future research directions are also highlighted.
Topics: Adsorption; Environmental Pollutants; Graphite; Water Pollutants, Chemical
PubMed: 31132618
DOI: 10.1016/j.jenvman.2019.05.047 -
Journal of Hazardous Materials Feb 2022As anthropogenic antibiotics, quinolones, e.g., ofloxacin have adverse impacts on ecological systems and human heaths. The removal of quinolones is of great importance,...
As anthropogenic antibiotics, quinolones, e.g., ofloxacin have adverse impacts on ecological systems and human heaths. The removal of quinolones is of great importance, and adsorption techniques have been widely used to remove this hazardous contaminant. However, a robust and easy-operating adsorbent is still emergently required due to the complex chemical structure of quinolones. In this study, we successfully synthesized the promising metallic carbons (MCs) containing carbon nanotubes and cobalt nanoparticles by carbonizing Zn/Co-ZIF at 900 °C. Three different molar ratios of Co and Zn were applied to optimize the adsorption capacity on ofloxacin (OFL). Results showed MC with molar ratio of Co and Zn at 3:1 (Co-CNT/NPC) achieved the maximal adsorption capacity to 118.3 mg g. Its adsorption performance was satisfied in the pH range from 5 to 9 and ionic strengths at 0.01 M. The main mechanisms for these adsorptions were identified as electrostatic attraction, metal coordination and π-π EDA. Removal efficiencies of quinolones higher than 68 mg g indicated the strong feasibility of this adsorbent for wastewater treatments. The regeneration of Co-CNT/NPC at 600 °C allowed its at least 4-time reusability and its magnetic property enabled external magnets to recycle it from real environments.
Topics: Adsorption; Humans; Nanotubes, Carbon; Quinolones; Water Pollutants, Chemical; Water Purification
PubMed: 34844338
DOI: 10.1016/j.jhazmat.2021.127181 -
Chemosphere May 2022The use of activated carbon is evidenced by the increased scope of carbon-based applications in various industrial applications including pharmaceutical antidotes,... (Review)
Review
The use of activated carbon is evidenced by the increased scope of carbon-based applications in various industrial applications including pharmaceutical antidotes, wastewater remediation, aquaculture and toxin removal. Activated carbon produced from biomass waste by various processing methods and conditions is emerging as a promising adsorbent for remediation of the ecosystem due to extensive discharge of pollutants. Methods of producing activated carbon, nature of lignocellulosic biomass waste, and interaction of adsorbent-adsorbate are some of the crucial factors that need to be scrutinized to produce an effective adsorbent. However, these factors have not been thoroughly discussed in the literature. Activated carbon needs to go through continuous and rigorous research and development through optimization of key parameters such as type of activation (physical/chemical) and processing conditions, especially for large-scale production. It is imperative to have a detailed understanding of the preeminent characteristics of the activated carbon such as pore size distribution, total pore volume, surface area, and yield of activated carbon that control the extents of adsorptions and production of activated carbon. To further clarify the involved mechanism, studies should focus on all the possible variables that influence the system. Therefore, this review provides a better understanding of factors that affect the production of an efficient activated carbon, important properties to be used as an adsorbent, and the involved mechanisms during the adsorption process followed by increasing demand for activated carbon in various fields.
Topics: Adsorption; Biomass; Charcoal; Ecosystem; Wastewater; Water Pollutants, Chemical
PubMed: 35093418
DOI: 10.1016/j.chemosphere.2022.133764 -
Journal of Environmental Management Nov 2023Equipped with hierarchical pores and three-dimensional (3D) center-radial channels, dendritic mesoporous nanoparticles (DMNs) make their pore volumes extremely large,... (Review)
Review
Equipped with hierarchical pores and three-dimensional (3D) center-radial channels, dendritic mesoporous nanoparticles (DMNs) make their pore volumes extremely large, specific surface areas super-high, internal spaces especially accessible, and so on. Other entities (like organic moieties or nanoparticles) can be modified onto the interfaces or skeletons of DMNs, accomplishing their functionalization for desirable applications. This comprehensive review emphasizes on the design and construction of DMNs-based systems which serve as sensors, adsorbents and catalysts for the detection, adsorption, and degradation of hazardous substances, mainly including the construction procedures of brand-new DMNs-based materials and the involved hazardous substances (like industrial chemicals, chemical dyes, heavy metal ions, medicines, pesticides, and harmful gases). The sensitive, adsorptive, or catalytic performances of various DMNs have been compared; correspondingly, the reaction mechanisms have been revealed strictly. It is honestly anticipated that the profound discussion could offer scientists certain enlightenment to design novel DMNs-based systems towards the detection, adsorption, and degradation of hazardous substances, respectively or comprehensively.
Topics: Hazardous Substances; Adsorption; Porosity; Nanoparticles; Metals, Heavy
PubMed: 37499417
DOI: 10.1016/j.jenvman.2023.118629 -
Journal of Molecular Graphics &... Jan 2023CaSiO is highly resistant to sintering and can trap arsenic at high temperatures in the boiler furnace. However, the trapping capacity of CaSiO for arsenic does not meet...
CaSiO is highly resistant to sintering and can trap arsenic at high temperatures in the boiler furnace. However, the trapping capacity of CaSiO for arsenic does not meet the requirements of practical applications, and it is easy to react with acidic gases, which significantly affects the adsorptive property of arsenic. In this paper, the effect of Al modification on the AsO adsorption behaviour on the CaSiO(001) surface was systematically investigated using a density functional theory. By comparing the magnitude of adsorption energy of different sites, the active site of AsO adsorbed on the surface of CaSiO(001) was determined to be Ca, and the adsorption activity of AsO by the silicon oxygen chain composed of [SiO] tetrahedron is deficient. The Si atoms in the [SiO] tetrahedral structure are directly replaced by Al atoms, the difference in bond length and bond energy between Al-O bond and Si-O bond is used to promote the redistribution of surface charge and the increase of local structural bond angle of CaSiO(001), leading to the exposure of new active sites (Si-top and Al-top sites) on the silicon oxygen chain. The new active site can realize the chemical adsorption of AsO, the higher adsorption energy of the Al-top site is attributed to the stronger s-p orbital hybridization between Al and O atoms after doping, which is more conducive to the charge transfer between AsO and the adsorbent surface. In this work, influence of SO and HCl gases on the adsorption of AsO by modified silicon oxygen chains was also discussed. The results show that SO and HCl in the flue gas may occupy the Al-top site on the silicon oxygen chain through chemical adsorption, and reduce the activity of this site, thereby affecting the adsorption of AsO. However, the exposed Si-top sites owing to Al doping show good acidic gas resistance, which in turn help the surface of Al-CaSiO(001) can also maintain stable adsorption of AsO in SO and HCl atmosphere.
Topics: Adsorption; Arsenic; Silicon; Gases; Oxygen
PubMed: 36242863
DOI: 10.1016/j.jmgm.2022.108357 -
Chemical Communications (Cambridge,... Jun 2023Effective separation of highly viscous crude oil/water mixtures remains a worldwide challenge. Employing special wettable materials with adsorptive properties as an... (Review)
Review
Effective separation of highly viscous crude oil/water mixtures remains a worldwide challenge. Employing special wettable materials with adsorptive properties as an emerging separation strategy has attracted extensive attention in the treatment of crude oil spillage. Such a separation technique combines excellent wettability materials and their adsorption performance to achieve energy efficient removal or recovery of high viscosity crude oil. Particularly, special wettable adsorption materials with thermal properties provide novel ideas and directions for the construction of rapid, green, economic and all-weather crude oil/water adsorption separation materials. Negatively, the high viscosity of crude oil makes most special wettable adsorption separation materials and surfaces extremely susceptible to adhesion and contamination in practical applications, leading to rapid functional failure. Moreover, such an adsorption separation strategy towards high-viscosity crude oil/water mixture separation has rarely been summarized. Consequently, there are still some potential challenges in separation selectivity and adsorption capacity of special wettable adsorption separation materials which urgently need to be summarized to guide the future development. In this review, the special wettability theories and construction principles of adsorption separation materials are first introduced. Then, the composition and classification of crude oil/water mixtures, particularly focusing on enhancing the separation selectivity and adsorption capacity of adsorption separation materials, are comprehensively and systematically discussed regulating surface wettability, designing pore structures and reducing crude oil viscosity. Meanwhile, the separation mechanisms, construction ideas, fabrication strategies, separation performances, practical applications, and the advantages and disadvantages of special wettable adsorption separation materials are also analyzed. Finally, the challenges and future prospects for adsorption separation of high-viscosity crude oil/water mixtures are expounded.
Topics: Adsorption; Viscosity; Wettability; Petroleum
PubMed: 37199096
DOI: 10.1039/d3cc00984j -
Ultrasonics Sonochemistry Apr 2022Understanding and manipulating geological pore structures is of paramount importance for geo-energy productions and underground energy storages in porous media....
Understanding and manipulating geological pore structures is of paramount importance for geo-energy productions and underground energy storages in porous media. Nevertheless, research emphases for long time have been focused on understanding the pore configurations, while few work conducted to modify and restructure the porous media. This study deploys ultrasonic treatments on typical geological in-situ core samples, with follow-up processes of high-pressure mercury injections and nitrogen adsorptions and interpretations from nuclear magnetic resonance and x-ray diffraction. The core permeability and porosity are found to increase by 8.3 mD, from 4.1 to 12.4 mD, and by 0.95%, from 14.03% to 14.98%, respectively. Meanwhile, the number and size of the micro- and mesopore are increased with progressing of ultrasonic treatment, while those of the macropore decrease, which finally increase the permeability and porosity. The increase of micro- and mesopore number, from x-ray diffraction results, is attributed to the migration and precipitation of clay minerals caused through ultrasonic wave. The relocation of clay minerals also helps to improve the pore-throat connectivity and modify the micro-scale heterogeneity. Basically, this study reveals the characterizations of geological pore reconfigurations post-ultrasonic treatments and interprets the associated mechanisms, which provides guidance to manipulate the geological pores and be of benefit for further porous media use in science and engineering.
Topics: Adsorption; Clay; Minerals; Porosity; Ultrasonics
PubMed: 35349969
DOI: 10.1016/j.ultsonch.2022.105990 -
Water Research Jul 2022GenX, the ammonium salt of hexafluoropropylene oxide dimer acid, has been used as a replacement for perfluorooctanoic acid. Due to its widespread uses, GenX has been...
GenX, the ammonium salt of hexafluoropropylene oxide dimer acid, has been used as a replacement for perfluorooctanoic acid. Due to its widespread uses, GenX has been detected in waters around the world amid growing concerns about its persistence and adverse health effects. As relevant regulations are rapidly evolving, new technologies are needed to cost-effectively remove and degrade GenX. In this study, we developed an adsorptive photocatalyst by depositing a small amount (3 wt.%) of bismuth (Bi) onto activated-carbon supported titanate nanotubes, Bi/TNTs@AC, and tested the material for adsorption and subsequent solid-phase photodegradation of GenX. Bi/TNTs@AC at 1 g/L was able to adsorb GenX (100 µg/L, pH 7.0) within 1 h, and then degrade 70.0% and mineralize 42.7% of pre-sorbed GenX under UV (254 nm) in 4 h. The efficient degradation also regenerated the material, allowing for repeated uses without chemical regeneration. Material characterizations revealed that the active components of Bi/TNTs@AC included activated carbon, anatase, and Bi nanoparticles with a metallic Bi core and an amorphous BiO shell. Electron paramagnetic resonance spin-trapping, UV-vis diffuse reflectance spectrometry, and photoluminescence analyses indicated the superior photoactivity of Bi/TNTs@AC was attributed to enhanced light harvesting and generation of charge carriers due to the UV-induced surface plasmon resonance effect, which was enabled by the metallic Bi nanoparticles. OH radicals and photogenerated holes (h) were responsible for degradation of GenX. Based on the analysis of degradation byproducts and density functional theory calculations, photocatalytic degradation of GenX started with cleavage of the carboxyl group and/or ether group by OH, h, and/or e, and the resulting intermediates were transformed into shorter-chain fluorochemicals following the stepwise defluorination mechanism. Bi/TNTs@AC holds the potential for more cost-effective degradation of GenX and other per- and polyfluorinated alkyl substances.
Topics: Adsorption; Bismuth; Charcoal; Nanotubes; Photolysis; Water
PubMed: 35640506
DOI: 10.1016/j.watres.2022.118650