Adsorption最新文献

Bathroom, and laundry greywater (GW) components are considered significant urban wastewater and are classified as hazardous substances that contaminate groundwater resources. Thus, achieving permitted levels for GW before discharging into the environment requires the removal or reduction, which has become a challenge. Various techniques have been developed to decontaminate GW from wastewater, comprising biological, chemical, filtration, adsorption, membrane separation, and photocatalytic degradation. Due to the simplicity, cost-effectiveness, abundance of materials, and capacity for facile scaling-up for remediation purposes, adsorption and photocatalysis technologies have been widely utilized in GW wastewater treatment. This review thus first explains the sources of GW and components found within this particular wastewater, which are critical for removal. The second part reviews various adsorbents or photocatalysts, including materials of macro, micro, and nanosize utilized for GW treatment. The review highlights the significance of activated carbon among all adsorbents under adsorption technology reviewed with the highest removal rate of chemical oxygen demand (COD), and biochemical oxygen demand BOD in GW. Moreover, the doped titanium dioxide photocatalyst also presented significant removal of COD, and BOD in GW within a shorter space of time. The impact of surface area and chemical functionalities of the adsorbent, and whilst aspect of nanostructure and absorptivity of photocatalyst in the visible region of the solar spectrum on the expedited removal of GW was also highlighted. Furthermore, this review emphasizes photocatalyst nanomaterial achieving a complete mineralization of different components present in GW, into mineral products.

Herein, the oxidized biochar (OBC) derived from rice straw was prepared and homogeneously embedded into TEMPO-mediated oxidized cellulose nanofiber (TOCNF). The resulting colloidal suspension, when mixed with OBC and crosslinked via ionic interaction using branched polyethyleneimine, forms nanocomposites with promising potential. The characterization of these composites, including SEM, EDX, surface morphology, and spatial elemental composition, reveals their unique properties. The effect of adding OBC to TOCNF at different ratios is estimated by surface area analysis following the BET and BJH methods. The adsorption settings for the as-formed composites were investigated to optimize the adsorption effectiveness of the fabricated sorbents. These conditions included contact time, Cd(II) concentration, pH, and sorbent dosage. With greater adsorption effectiveness of 70% and 90% at 1 h and 2 h, the nanocomposite with an equal ratio of OBC and TOCNF was discovered to be a valuable sorbent for Cd(II) elimination (0.15 g of BCC3 composite in 50 mL of 100 mg/L Cd(II) at pH 7.0). The adsorption process was modeled using kinetic and isotherm models. The correlation coefficients for the pseudo-first and second-order kinetics are similar and closest to 1.0 based on the data. Thus, Cd(II) adsorption may involve both physio-sorption and chime-sorption. Additionally, the linear fitting of the Freundlich isotherm model demonstrated a heterogeneous and multilayer surface interaction with the greatest adsorption capability of 44 mg/g. Suggesting potential applications in environmental engineering and materials science.

An important factor that defines the behavior of Ferric magnetic nanoparticles (FeMNPs) in environmental applications is the particle size. In this work, the researcher sought to utilize Artificial Neural Networks (ANN) and a regression learner, developed on Matlab software, to predict the particle size of FeMNPs. More precisely, the experiments involved the prediction of particle size of FeMNPs during their synthesis using celery extract. The characterization studies using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) analyses showed that the optimal experimental conditions gave the particle size of 18.01 nm. The two models that have been created for the prediction of particle size include Artificial Neural Network and Regression Learner using pH, reaction time, temperature, and celery extract concentration as parameters. From the analysis of the obtained graphs and the value of the mean square error of the ANN model equal to 0.0142, it was evident that the predictive capability of the model was satisfactory and in good agreement with the experimental data. The reliability of the predictions was further verified by the regression learner model, as from a data point, the predicted and actual particle sizes were 18.41 nm and 18 nm at pH 9. Thus, these models are believed to be efficient and precise in particle size prediction; moreover, they appear to be a useful tool for the optimization of the process factors.

Ionic liquids (ILs) are liquids composed of pure ionic components with melting points near room temperature that exhibit unique properties. They are also known as designer solvents. In particular, π-conjugated functional ILs demonstrate photoluminescent properties, making them promising for new applications. In addition, the organic moieties of ILs can function as precursors for carbon materials, facilitating efficient polymerization reactions at high temperatures. In this paper, we present the structural aspects of nanoporous carbon materials derived from π-conjugated ILs, revealing that the domain structure of these ILs plays a crucial role in the carbonization process, as observed from the florescence spectroscopy of the precursor π-conjugated IL. This paper proposes a synthesis process for nanoporous carbon from π-conjugated ILs, demonstrating the thermal stability of ILs with mesoscopic domain structures, thereby promoting carbonization reactions while pore formation occurs simultaneously. This study expands the potential applications of π-conjugated ILs across various fields, and contributes to a deeper understanding of their unique properties from microscopic observations.

Zinc oxide nanotubes (ZnONTs) are a promising option for various drug delivery systems due to their non-cytotoxic and chemically stable properties. This study investigates the drug delivery capabilities and adsorption properties of ZnONTs as a delivery vehicle for the anti-cancer drug chlormethine (CM) using density functional theory (DFT) and considering solvent effects. The results indicate that the Zn atoms on the ZnONT surface are the most favorable sites for CM adsorption. The Cl atom in the chlormethine (CM) drug binds strongly to the pyramidal site of the zinc oxide nanotube (ZnONT), resulting in favorable physical adsorption. In this configuration, the Cl atom of CM interacts with a Zn atom of the ZnONT at a distance of 2.090 Å, with an adsorption energy of -20.45 kcal/mol. To explore attributes of drug-nanotube complex in the excited state, UV-vis data of interaction of CM/ZnONT system has been investigated. The maximum absorption wavelength of the drug shows a significant shift towards the red end of the spectrum when it is adsorbed on the surface of the nanotube. This suggests that the nanotube could also be used as an optical sensor to detect and monitor the presence of the drug molecule. In low pH, mechanism of drug release reveals CM can be released in cancer tissues. This research presents precise mechanism of CM interaction with ZnONT and shows that ZnONT is proper option as delivery vehicle for CM.

Pharmaceutical contamination of wastewater poses a significant threat to aquatic ecosystems and human health. Traditional wastewater treatment methods often struggle to effectively remove these emerging contaminants. This study investigated the potential of MIL-101(Fe)-NH₂-Cyclodextrin nanofibers as a novel adsorbent for removing pharmaceutical contaminants from wastewater. The performance of this material was compared to traditional Electrospun Pineapple Leaf Fiber, an alternative bio-based adsorbent. MIL-101(Fe)-NH₂-Cyclodextrin nanofibers exhibited significantly enhanced adsorption capacity and kinetics compared to Pineapple Leaf Fiber. For example, at an initial concentration of 100 mg/L and pH 7, MIL-101(Fe)-NH₂-Cyclodextrin nanofibers achieved a removal efficiency of 96 ± 2% for Ciprofloxacin, while Pineapple Leaf Fiber only achieved 65 ± 3.5%. This superior performance is attributed to the material’s high BET surface area (1220 m²/g) and broad pore size distribution, providing a vast surface area for contaminant adsorption and an intricate network for trapping contaminants as well as cyclodextrin-functionalized active sites, which enhance host-guest interactions and hydrogen bonding. Furthermore, MIL-101(Fe)-NH₂-Cyclodextrin exhibited faster adsorption kinetics, achieving equilibrium within 60 min for Ciprofloxacin, compared to 120 min for Pineapple Leaf Fiber. These findings suggest that MIL-101(Fe)-NH₂-Cyclodextrin nanofibers offer a promising alternative to traditional adsorbents for removing pharmaceutical contaminants from wastewater. Its high removal efficiency, fast kinetics, and potential for reusability make it a valuable tool for addressing the increasing issue of pharmaceutical pollution in aquatic environments. Further research is needed to optimize its performance and assess its feasibility for real-world applications, but this study offers a compelling roadmap for developing innovative and effective solutions for safeguarding our water resources.

Various types of pollutants, including dyes, pharmaceuticals, heavy metals, and other contaminants, pose significant risks for aquatic species and humans. Photocatalytic hydrogels (PCHs), which synergistically combine adsorption and photocatalysis, offer a promising solution by combining the adsorption and photodegradation of these contaminants under UV or visible light. Photocatalysts such as TiO₂, ZnO, Ag, Bi, and non-metallic catalysts can be incorporated into diverse hydrogel matrices, providing flexibility for designing PCHs tailored to specific applications. This review explores the synthesis, properties, and performance of various PCHs, with a focus on their ability to adsorb and/or degrade contaminants such as dyes (e.g., methylene blue, methyl orange, rhodamine B), pharmaceuticals (e.g., tetracycline, ciprofloxacin, 17 estradiol), biological contaminants (e.g., algal blooms), and heavy metals (e.g., Cr (VI)). Additionally, the recyclability of PCHs is addressed. PCHs represent a versatile and eco-friendly approach to advancing water remediation technologies.

This work aimed to synthesize and characterize activated carbon derived from durian wastes, a substantial agricultural by-product in Thailand, with a focus on its efficacy in aqueous phenol removal. The activated carbon derived from durian seed (AC-DSE) and activated carbon derived from durian shell (AC-DSH) was prepared using phosphoric acid (H₃PO₄) as the activating agent, subsequently, carbonization occurred under a nitrogen atmosphere. The synthesized samples underwent comprehensive characterization. In phenol removal, the adsorption performance of the AC-DSE was notable, achieving a phenol removal efficiency of around 90% within 180 min, employing 0.1 g of AC-DSE for 20 ml of aqueous phenol solution (initial concentration: 10 mg/l). Compared with AC-DSH and a commercial activated carbon, the obtained AC-DSE exhibited the highest phenol removal due to high specific surface area of 2,054 m²/g, with an average pore size of 3.85 nm, micro, and mesopore volumes of 1.43 and 2.27 cm³/g, respectively. Moreover, the adsorption behaviour followed to the Langmuir model, while the experimental data closely aligned with the pseudo-second-order kinetic model. These findings emphasize the potential of activated carbon derived from durian waste as a sustainable adsorbent for organic removal from wastewater.

Ammonia (NH₃), a noxious gas, not merely poses a threat to human beings but also serves as a significant hydrogen carrier. The matter related to its emission is naturally highly deserving of people’s meticulous attention and in-depth research. Taking into account the substantial harm that ammonia inflicts upon the environment and the human body, the storage of ammonia is indisputably an inevitable aspect in the course of green development. Simultaneously, ammonia finds extensive applications and serves as an indispensable raw material for numerous fertilizers, food, explosives, and even medicines. When employed as a fuel, ammonia boasts numerous advantages, rendering it a widely utilized and highly promising gas. Therefore, the storage of ammonia is extremely worthy of profound exploration. Currently, the principal ammonia treatment technologies comprise adsorption, absorption, catalytic conversion, biological treatment, and plasma treatment. The research and development of adsorption materials constitutes the crucial link in ammonia gas adsorption, and the storage materials for ammonia are also highly diverse. This paper integrates a considerable number of various literatures and experiments from multiple perspectives to furnish a comprehensive summary of the current research and achievements in ammonia adsorption and desorption. The materials involved mainly consist of some metal chlorides, metal oxides, zeolites, and MOF materials. Metal chlorides are highly prone to forming amide complexes with ammonia. Metal oxides are a type of compounds composed of metal elements and oxygen elements, which are typically highly stable in nature and have wide-ranging applications in various fields. Research on the utilization of metal oxides as ammonia adsorbents has consistently been a focus for scholars in different countries. The microporous structure of zeolite is extremely well-developed, which results in an exceptionally high specific surface area. This high specific surface area provides a considerable amount of contact space for molecules, thereby significantly enhancing the adsorption efficiency of the adsorbent.

Graphical abstract

Calgary Framework 20 (CALF-20) is a metal-organic framework deployed for industrial post-combustion CO₂ capture. This work explores capturing CO₂ from a humid stream using CALF-20. A four-step vacuum swing adsorption (VSA) cycle incorporating a light product pressurization step was examined. Two columns packed with structured CALF-20 were used to perform VSA experiments over a wide range of relative humidity (RH) values (13%, 25%, 45% and 70% RH). Key process performance indicators, purity, recovery and productivity were measured and compared with the dry case basis. At low to intermediate relative humidity (13-45% RH), the difference between the dry and the wet VSA cycle was minimal. The purity and recovery were approximately 95% and 71% in Case Study 1, and 92% and 81% in Case Study 2, respectively. The temperature and composition histories were similar to the dry. At high relative humidity (70% RH), while CALF-20 could still achieve similar purity, recovery and productivity, reaching low pressure during the evacuation step was difficult due to the water condensation. Each experiment was run for several days (hundreds of cycles) to confirm the long-term stability of the material. CALF-20 also showed good cyclic durability; minimal loss in the CO₂ capacity from the used CALF-20 sample (~ 10,000 cycles) was observed.