Adsorption最新文献

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.

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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.

The discharge of chromium-contaminated wastewater from industries such as ferrochrome plants and leather manufacturing poses a significant environmental challenge due to the toxic and carcinogenic properties of Chromium [Cr(VI)]. Nanoparticles have emerged as one of the most effective solutions for wastewater treatment due to their high surface area, enhanced reactivity, and ability to target specific contaminants. In recent years, their eco-friendly synthesis, scalability, and efficiency in removing heavy metals and other pollutants have made them vital in addressing environmental challenges, particularly in industrial wastewater management. Their unique properties make them indispensable in modern wastewater treatment technologies. This study explores the application of biogenically synthesized titanium dioxide (TiO₂) for removal of Cr(VI) from synthetic wastewater. Lemon grass leaf extracts has been used as potential precursor in synthesis of TiO₂ nanoparticles from readily available micro size particles of TiO₂ powder. The process was further enhanced by ultrasonic assistance, which promoted the formation of uniformly dispersed nanoparticles with high surface area, improving their adsorption. Experimental techniques, such as X-ray Diffraction, have been utilized to confirm the biogenic synthesis of TiO₂ nanoparticles, demonstrating a size reduction from 10 μm to 35.79 nm. The nanoparticles demonstrated excellent Cr(VI) removal efficiency, achieving 84.55% reduction under optimal conditions. Among the various adsorption isotherm models, the Freundlich model proved to be the best fit, with an R² value exceeding 0.997. This method not only leverages sustainable synthesis processes but also offers potential scalability for industrial applications in waste water treatment.

This study efficiently removed aluminum from commercial wastewater by using different doses of the novel chitosan-tannic acid (CT1, CT3, and CT6) bio-materials adsorbent. The Al³⁺ ions were determined using 797 VA anodic linear sweep voltammetry Computrace. The research examined the adsorption kinetics, adsorption isotherms, and the effect of the solution flow rate. The Freundlich isotherms precisely represented the adsorption results, with a maximum adsorption capacity of adsorbent was 684.93 mg/g. The experimental results showed that the adsorption of aluminum was maximum when solution concentrations were up to 200 mg/L. The findings indicated that the chitosan-tannic acid biomaterials primarily followed a complexation-adsorption method, exhibiting maximum adsorption capacity at pH 6.5. The study investigated the BET adsorption–desorption isotherm and evaluated the adsorption efficacy of adsorbents. Consequently, this novel, sustainable chitosan-tannic acid complex might be a successful bio-adsorbent for removing aluminum metal ions from wastewater solutions.

This study investigates the adsorption capacity (q_max) of synthesized ferrocene-modified activated carbon (AC-H₃PO₄/Fe₇S₈) for the removal of phenol in wastewater. The structural and morphological features of the synthesized composite were determined using FTIR, BET, XRD, and SEM. With an average pore size of 59.127 nm, AC-H₃PO₄/Fe₇S₈ composite achieved 98% removal efficiency of phenol at optimal conditions comprising adsorbent dosage of 0.3 g, contact time of 120 min, pH of 4, and concentration of 50 mg/L. The Freundlich isotherm model displayed R² values of 0.9965 and 0.9955, while the evaluated maximum adsorption capacities were 9.15 and 13.32 mg/g for AC-H₃PO₄ and AC-H₃PO₄/Fe₇S₈ respectively. The adsorption kinetics was also fitted into a Pseudo second-order kinetic model with a rate constant of 0.10462 min⁻¹ at optimal conditions. The thermodynamics parameters suggested that the reaction was spontaneous and endothermic with increased randomness. The findings describe the synthesized AC-H₃PO₄/Fe₇S₈ composite as a promising adsorbent for the removal of phenol wastewater treatment.

In response to the growing threat of pollution and its adverse effects on human health, a novel and innovative method for preparing SO₂ adsorbents has been developed. The present study introduces a unique approach that combines activated carbon (AC), chitosan (CS), and polyionic liquids (PILs) to create highly effective composite adsorbents. Incorporating 4%, 7%, and 10% by weight of butyl and octyl PILs into the composite beads led to a significant enhancement in SO₂ adsorption capabilities. The PILs were synthesized through direct polymerization and meticulously characterized using Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), confirming their successful synthesis and high thermal stability. The activated carbon was effectively impregnated with the PILs, and the resulting composite beads were shaped into CS beads. Gas adsorption studies revealed that the AC-CS-PIL beads impregnated with butyl and octyl PILs nearly doubled the adsorption capacity compared to raw activated carbon. Notably, the 10% octyl AC-CS-PIL composite exhibited the highest breakthrough time of 37.08 min and an impressive adsorption capacity of 445 mg/g, which is 2.4 times greater than that of raw AC. These results highlight the promising potential of this innovative adsorbent in effectively combating pollution and improving air quality.

Through a statistical physics modeling approach, a detailed theoretical scrutiny was conducted utilizing four distinct models based on the grand canonical ensemble to fit the Methylene Blue adsorption isotherms onto Sodium StyreneSulfonate-co-Dimethylacrylamide (NaSS-DMA) hydrogel surface. Steriographic along with energetic-thermodynamic metrics have been inspected in response to combined effects of temperature and concentration. The uptake process was best described by a bimodal-energy linking monolayer scenario involving two sites and energies ((varepsilon_{1}) = 15.73 kJ/mol and (varepsilon_{2}) = 17.85 kJ/mol) characterized by a multi-molecule adsorption process (n₁ = 8.383 and n₂ = 2.5967) at T = 295 K. Steriographic discussion revealed that the position of the adsorbate is non-parallel but a larger number of entities can be linked in the same receptor site. The adhesion reaction is exothermic and when the concentration exceeds 95 mg/L, the adsorbed amount decreases significantly in response to incremented heat conditions. More importantly, the investigated linking process is primarily driven by weak van der Waals forces (energies below 45 kJ/mol) while the negative values of Gibbs free energy validated its spontaneity. These outcomes supported the development of a robust mathematical framework that accurately predicts removal efficiencies of Methylene Blue onto NaSS-DMA hydrogel surface providing a deeper understanding of the involved nanoscale surface linking. The findings can be effectively translated into real-world applications for water treatment and environmental detoxification through the use of super-adsorbent hydrogels. By leveraging their optimized steric, energetic and thermodynamic properties, these hydrogels exhibit exceptional adsorption efficiency, enabling the removal of hazardous contaminants like Methylene Blue from polluted water systems. Their high capacity for adsorption, combined with stability and reusability, makes them ideal for large-scale applications in wastewater treatment plants and industrial effluent management. Finally, their compatibility with existing water purification technologies allows seamless integration into current systems, offering a cost-effective, sustainable and scalable solution for addressing water pollution challenges.

This study presents a detailed numerical analysis of perovskite solar cells to optimize their photovoltaic performance through systematic parameter variation. Key parameters, including absorber layer thickness, bandgap tuning, metal back contacts, and interface layer properties, were investigated for their influence on device performance. The optimized device configuration achieved a power conversion efficiency of 29.39%, a fill factor of 85.54%, a short-circuit current density of 28.37 mA/cm², and an open-circuit voltage of 1.21 V. The study highlights the critical role of these parameters in enhancing quantum efficiency, current-voltage characteristics, and overall device stability. These findings provide a scientific framework for material selection and device engineering, paving the way for advancements in the design and fabrication of high-performance perovskite solar cells and contributing to the development of sustainable energy technologies.