Adsorption最新文献

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.

This study investigated the use of functionalized cabuya fibers (FCF) as an effective adsorbent for Hg (II) removal from aqueous solutions. The composition, surface properties, and morphology of the FCF were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), and Fourier transform infrared spectroscopy (FTIR). The effects of the pH, contact time, temperature, adsorbent dosage, and initial Hg (II) concentration on the adsorption process were studied. Under optimized experimental conditions, FCF achieved a removal efficiency exceeding 92%, with a maximum adsorption capacity of 8.29 mg/g. The experimental data for the FCF isotherm were analyzed using the Langmuir, Freundlich, DR, and Temkin adsorption models. Notably, the Langmuir isotherm exhibited the highest R² value of 0.99, indicating the model’s strong applicability. The pseudo-second-order kinetic model k₂ = 0.42 mg/g.min was employed to elucidate the adsorption mechanism. Thermodynamic studies of the adsorbent FCF were conducted, and ΔG° (-6.16 kJ/mol), ΔH° (36.29 kJ/mol), and ΔS° (141.98 kJ/mol·K) were calculated, assessing the feasibility of the process. Additionally, the desorption results of FCF were evaluated, demonstrating that it can be reused for up to three cycles, achieving adsorption rates of 74% and 62% in the third cycle. This indicates its stability and recycling capacity. Finally, the effectiveness of the FCF was demonstrated by eliminating approximately 91% of Hg (II) from real mineral water samples in Ecuador. These results highlight the p of FCF as promising, eco-friendly, and sustainable adsorbents for the remediation of Hg (II) contamination in aquatic systems.

Metal organic frameworks (MOFs) have demonstrated remarkable performance in hydrogen storage due to their unique properties, such as high gravimetric densities, rapid kinetics, and reversibility. This paper models hydrogen storage capacity of MOFs utilizing numerous machine learning approaches, such as the Deep Neural Network (DNN), Convolutional Neural Network (CNN), and Gaussian Process Regression (GPR). Here, Radial Basic Function (RBF) and Rational Quadratic (RQ) kernel functions were employed in GPR. To this end, a comprehensive databank including 1729 experimental data points was compiled from various literature surveys. Temperature, pressure, surface area, and pore volume were utilized as input variables in this databank. The results indicate that the GPR-RQ intelligent model achieved superior performance, delivering highly accurate predictions with a mean absolute error (MAE) of 0.0036, Root Mean Square Error (RMSE) of 0.0247, and a correlation coefficient (R²) of 0.9998. In terms of RMSE values, the models GPR-RQ, GPR-RBF, CNN, and DNN were ranked in order of their performance, respectively. Moreover, by calculating Pearson correlation coefficient, the sensitivity analysis showed that pore volume and surface area emerged as the most influential factors in hydrogen storage, boasting absolute relevancy factors of 0.45 and 0.47, respectively. Lastly, outlier detection assessment employing the leverage approach revealed that almost 98% of the data points utilized in the modeling are reliable and fall within the valid range. This study contributed to understanding how input features collectively influence the estimation of hydrogen storage capacity of MOFs.

The adsorption kinetics of carbon dioxide (CO₂) in three cationic forms of binderless pellets of Y-types zeolites (H-Y, Na-Y, and TMA exchanged Na-Y) are studied using the zero-length column (ZLC) technique. The measurements were carried out at (288.15,textrm{K},298.15,textrm{K}) and ({308.15},textrm{K}) using different flowrates and an initial CO₂ partial pressure of ({0.10} ,textrm{bar})– conditions representative of post-combustion CO₂ capture applications. The mass transport within the adsorbent pellets was described using a 1-D Fickian diffusion model accounting for intra- and inter-crystalline mass transport. For the latter, the parallel pore model formulation was used to explicitly account for the adsorbent’s macropore size distribution in estimating the volume-averaged diffusivity of the gas. Experiments carried out using different carrier gases, namely helium and nitrogen, were used (i) to determine that these systems are macropore diffusion limited and (ii) to simplify the parameter estimation to a single parameter - the macropore tortuosity. The latter ((tau =1.3-2.5)) was in good agreement with independent measurements using MIP ((tau approx 1.7)). The associated diffusion coefficient, (D^textrm{e}_textrm{mac}), was found to vary due to differences in the materials’ macropore size distributions and overall porosity. Upon combining the parallel pore model formulation with the temperature dependencies for the pore diffusivities derived from molecular theories of gases, we predict (D^textrm{e}_textrm{mac}propto {T^b}) with (b=[0.78-0.88]) depending on the macropore size distribution. Notably, for the range of temperature tested in this study, (D^textrm{e}_textrm{mac}) varies approximately linearly with temperature ((bapprox 1))– in contrast to the commonly reported correlation of (b=1.75), which may be more appropriate for systems where molecular diffusion dominates and Knudsen diffusion is negligible. The binderless pellets of Y-type zeolites studied exhibit generally higher values for the effective macropore diffusivity of CO₂ compared to previously reported results on commercial FAU zeolites.

With advances in industrialization, water pollution has become an increasing concern, and research must be directed towards developing solutions to address this growing threat to both human health and ecosystems. This current paper is devoted to investigating the adsorption of a phenolic material, 3-aminophenol (AMP)—a raw material used in dye production—on activated carbon derived from avocado seed adsorbent (ASAC) for the purpose of remediating polluted water. Rooted in a statistical physics approach, five distinct models were applied to fit the empirical data: the single-energy monolayer model (Model 1), dual-energy monolayer model (Model 2), tri-energetic monolayer model (Model 3), single-energy bilayer model (Model 4) and dual-energy bilayer model (Model 5). Additionally, a topographic examination was conducted to assess the pore size distribution (PSD) and the adsorbed energy distribution (AED), contributing significantly to the comprehensiveness of linking reaction. It appears that the model 1 provides the most accurate fit, based on the convergence criteria (R², R²_Adj and RMS). By exploiting the involved variables of Model 1, we have quantified three thermodynamic properties (entropy, Gibbs free energy, and internal energy) as a function of distinct temperature and concentration intervals. Stereographic elucidation has revealed that the number of adsorbed molecules per site (n) is typically below 0.5, indicating that adsorbate entities are trapped through the action of one or more adhesion cavities. Meanwhile, the orientation of linked entities is parallel, interacting with two or more sites. The abundance of receptor sites, N_m, significantly increased from 643.8853 to 812.3822 mg/g when the temperature was raised from 303 to 323 K. The computed adhesion energies confirmed were below 40 kJ/mol, indicating an exothermic physisorption associated with van der Waals forces and hydrogen bonding. The adsorbent/adsorbate system is likely spontaneous, as the analysis of Gibbs free energy yielded negative results. Finally, PSD analysis suggested that the adsorbent surface is predominantly composed of macropores. Additionally, AED inspection confirmed the physisorption mechanism.