Adsorption Breakthrough Research Articles

Three-dimensional covalent organic frameworks with nia nets for efficient separation of benzene/cyclohexane mixtures

The synthesis of three-dimensional covalent organic frameworks with highly connected building blocks presents a significant challenge. In this study, we report two 3D COFs with the nia topology, named JUC-641 and JUC-642, by introducing planar hexagonal and triangular prism nodes. Notably, our adsorption studies and breakthrough experiments reveal that both COFs exhibit exceptional separation capabilities, surpassing previously reported 3D COFs and most porous organic polymers, with a separation factor of up to 2.02 for benzene and cyclohexane. Additionally, dispersion-corrected density functional theory analysis suggests that the good performance of these 3D COFs can be attributed to the incorporation of highly aromatic building blocks and the presence of extensive pore structures. Consequently, this research not only expands the diversity of COFs but also highlights the potential of functional COF materials as promising candidates for environmentally-friendly separation applications.

Dual-alkali treatment of Y-type zeolite synthesized from lithium-silicon powder waste for enhanced adsorption removal of low-concentration toluene

In this study, the dual-alkali treatment of the Y-ZLSP zeolite recycled from lithium-silicon powder (LSP) waste for enhanced adsorption removal of low-concentration toluene was systematically studied. The results revealed that a mild condition dual-alkali treatment of Y-ZLSP significantly improved its toluene adsorption performance, as well the regenerability and robustness. The Y-ZLSP-NT(1/1) that was obtained under the conditions of NaOH and TPAOH molar ratio at 1/1, total concentration of 0.0050 M, and treated at 55 °C for 0.5 h showed the best adsorption property, with a saturated adsorption capacity (qs) of 139.7 mg/g at 1000 mg/m3 inlet concentration. Importantly, it had an up to 112.1 mg/g high of breakthrough adsorption capacity (qb). Toluene adsorption on Y-ZLSP-NT(1/1) was governed by physical adsorption, primarily due to pore filling and hydrogen bonding. The dual-alkali treatment resulted in a controllable pore evolution and greatly enriched the surface acid functional groups of Y-ZLSP. The evolved microporosity provided more adsorption sites, the mesoporosity afforded mass transfer channels. The toluene adsorption on Y-ZLSP-NT(1/1) follows a pseudo-first-order model and is typically an entropy-driven exothermic process with ΔH, ΔG and ΔS of −1.98 kJ/mol, −8.29 kJ/mol and 34.50 J/(mol·K), respectively.

Hydrogen Sulfide Adsorption Mechanism and Breakthrough Curves of Highly Stable Na-, Na-H-, Ca- and K-Mordenites.

Hydrogen sulfide (H2S) is a hazardous gas found in natural gas and biogas, lethal over 100 ppm. When released into the atmosphere, it can turn into sulfur dioxide. One option to remove H2S is using porous materials such as zeolites. Among them, mordenite stands out due to its channel structure, wide availability, and low cost. In this work, we evaluated the H2S adsorption capacity of mordenite using a volumetric static method. The results show the adsorption capacity of H2S in mordenite varies with the exchanged cation. The highest was measured in Na-mordenite (~4.08 mmol H2S/g mordenite). The experimental breakthrough curves for this zeolite confirmed Langmuir-type adsorption and strong affinity between Na+ cations and H2S. Despite this interaction, the XRD diffractograms of Na-mordenite show that the material retained its crystalline structure. More information about the differences in the amount of H2S adsorbed in the zeolites caused by the change in exchanged cation was obtained by H2S adsorption followed by FTIR spectroscopy. The spectra show differences in the position of the peaks related to the different adsorption modes of H2S caused by a change in the polarizing power of the cations due to their charge and position inside the zeolite pores.

Monitoring of sugars adsorption breakthrough curves with online Raman spectroscopy

We introduce a new application for online Raman spectroscopy to monitor adsorption breakthrough curves of a glucose and xylose mixtures. Univariate and multivariate Partial Least Squares (PLS) calibration models are developed for each sugar when they are dissolved in water and in the case of the ethanol addition as a cosolvent. The models are validated by performing actual breakthrough experiments in a liquid phase using a column packed with a zeolite adsorbent. The first statistical moments of predicted curves are compared to the reference curves obtained with offline High-Performance Liquid Chromatography (HPLC). Glucose and xylose univariate predictions in the presence or absence of ethanol in the mixture are accurate and no improvements are found with the PLS models. Spectral subtraction coupled with the first derivative proved to be effective pretreatments to develop robust univariate models.

Effects of mesopore size on ethyl acetate adsorption–desorption behaviors over hierarchical ZSM-5/MCM-41 molecular sieves

A series of micro-mesoporous structure ZSM-5/MCM-41 composites with different mesopore sizes were successfully fabricated through surfactant-mediated recrystallization method using the template agents with different alkyl chain length. Mesopore pore sizes were tuned from 2.11 nm to 5.09 nm. Taking ethyl acetate as the VOC probe molecule, the adsorption and desorption properties were evaluated by the dynamic adsorption breakthrough curves and TPD experiments. Results showed that the adsorption capacity was enhanced under dry and humid condition owing to the introduction of mesopore size structure. Especially for ZSM-5/MCM-41 (C12), its adsorption capacity reached up to 208.92 mg·g−1 and 82.29 mg·g−1 at dry and saturated humidity (4 v/v% H2O). Simultaneously, the hierarchical molecular sieves exhibited an excellent regeneration performance. Even after the fifth cycle, above 86% adsorption capacity remained under humid condition. Moreover, the adsorption kinetics of ethyl acetate on ZSM-5/MCM-41 composites followed the Bangham model. The results indicated that hierarchical composite molecular sieve can be considered as a potential adsorbent for VOCs removal.

Micropore system properties significantly influence the Na-type zeolite adsorption of the carbon disulfide impurity in mimetic coke oven gas

The experiments of the adsorption removal of CS2 impurity from a mimetic coke oven gas were performed by using a series of Na-type zeolites as adsorbents. Combining with the diffusion & simulation calculations and several characterizations, it's found both the development degree and the diffusion ability of microporous systems significantly influence the adsorption performance of these Na-type zeolites on which the physical absorption was predominant for CS2 molecules. Firstly, compared with NaZSM-5 or NaSAPO-34, the NaY with FAU-type framework exhibited a much higher breakthrough adsorption capacity, primarily due to its much higher microporous surface area & volume and larger-size channels, which ensured a broader adsorption space, a high-efficiency molecule-diffusion and a high adsorption utilization of micropores. Secondly, alkali-treatment introduced some mesopores into NaZSM-5 crystals but also resulted in a declined integrity of microporous structure, causing an obvious decline of adsorption performance. Thirdly, the nano-crystal NaZSM-5 or NaY exhibited a much higher breakthrough adsorption capacity than that of the corresponding micron-crystal zeolite, primarily attributed to both the increased microporous surface area & volume and the shortened micropore diffusion-path length of the former. In addition, a breakthrough adsorption capacity of up to 0.251 g/g was obtained in the first adsorption use of a nano-NaY-0.909 sample at 298 K, and it's 0.229 g/g in even the sixteenth time of operation (by then, total adsorption service hours were 80.58 h). Our work may provide an important reference for developing high-performance adsorbents for removing gaseous CS2 impurity in coke oven gas.

Research Investigates and Simulation Behavior of the Failure Characteristics of Red Mud–Loess Type Permeable Reactive Barriers PRB in Fixed‐Bed Column Experiments

Controlling and remediating water and soil pollution while efficiently utilizing solid waste is essential for comprehensive environmental protection and sustainable development, particularly in establishing green, low‐carbon economic systems in China. We evaluate the impact of initial concentration, flow rate, and bed height on breakthrough performance and adsorption capacity using the Tessier method under dynamic water flow conditions. Additionally, we analyze micromorphological changes in the red mud–loess mixture before and after breakthrough by acid mine drainage containing Pb and Cd in mining areas, employing soil column experiments and numerical simulations with COMSOL Multiphysics. Our findings suggest that reducing initial concentration and flow rate while increasing bed height leads to higher breakthrough time, saturation time, and adsorption capacity for Pb and Cd in the red mud–loess mixture (7 : 3). Furthermore, the red mud–loess blend (7 : 3) demonstrates sustained and efficient acid‐buffering capability in the presence of acid mine drainage containing Pb and Cd. Notably, under specific conditions (initial Pb content at 100 mg/L, a height of 7 cm, and flow rate set at 1 mL/min), the adsorption capacity of red mud–loess (7 : 3) reaches 17.30 mg/g. The prescribed minimum length for PRBs is 11.40 cm. Under specified conditions (Cd concentrations at 100 mg/L, a height of 5 cm, and a flow rate of 1 mL/min), the material exhibits a notable adsorption capacity of 29.91 mg/g, with a theoretical minimum length for PRBs at 8.95 cm. Increasing bed heights successfully remove Pb and Cd ions through chemical precipitation. The BDST model accurately describes the breakthrough curves of Pb and Cd and develops a correlation formula for the breakthrough time of red mud–loess PRB medium. As the saturation of Pb increases from 0.05 to 0.85, the maximum volume adsorption capacity of Pb increases from 1.78 to 2.98 mg/L, while for Cd, it increases from 4.15 to 7.87 mg/L. Elevating the bed height first triggers chemical precipitation, hence improving Pb and Cd removal. Consequently, the longevity of red mud–loess PRB in acidic mine effluent containing Pb and Cd surpasses predicted theoretical outcomes. These observations reveal correlations between the breakthrough length for red mud–loess permeable reactive barriers and the bed height. Furthermore, the distribution of Pb speciation within the red mud–loess mixture (7 : 3) is primarily governed by the presence of iron–manganese oxide, while the composition of Cd speciation is chiefly influenced by the carbonate form and iron–manganese oxide. After treating acidic mine wastewater with Pb and Cd, the red mud–loess mixed material (7 : 3) undergoes surface changes, shifting from smooth to rough due to H+ corrosion. Pores between particles enlarge, yet heavy metal ions, adsorbates, and precipitates reoccupy and cover the surface, transforming the particle morphology from dense lamellar to clustered spherical. Our innovative approach to combining waste materials for environmental remediation presents a cost‐effective and impactful solution for heavy metal pollution.

Oil palm waste-derived reduced graphene oxide (rGO) for dynamic adsorption of dye in a fixed-bed system

This study focuses on investigating the dynamic adsorption of Rhodamine B (RhB) from reduced graphene oxide (rGO) derived from oil palm waste. The synthesis of rGO from palm kernel shell (PKS) was achieved through double oxidation and carbonization method, resulting in a yield of 73.5 wt%. The reduction of oxygen-containing functionalities process using PKS was confirmed by FTIR spectroscopy, microscopic evaluation, and X-ray diffraction analyses. Laboratory-scale fixed-bed experiments were conducted with various process parameters. Both PKS and rGO were used as adsorbents, and a comparison was made based on breakthrough curve analysis, adsorption capacity and percentage removal of dye. The adsorption kinetics of RhB on PKS and rGO were best described by the non-linear Yoon-Nelson model, with a high adsorption capacity of 88.32 mg/g and 195.24 mg/g respectively. Using both PKS and rGO, the maximum adsorption capacity was observed when using 10 cm bed depth column, inlet dye concentration of 5 mg/L, flow rate of 12 mL/min and pH of 7. PKS exhibited good dye removal with an efficiency of 66.54%. Meanwhile, the exothermic behavior highlighted the potential of utilizing rGO for maximum dye removal, achieving an efficiency of 90.35%. This study justifies rGO as a cost-effective superior dye removal adsorbent, providing new prospect for large-scale dye removal.

Green synthesis approach using deep eutectic solvents to enhance the surface functional groups on porous carbon for CO2 capture

This study explores the potential of green solvents using amino acids-based deep eutectic solvents to alter surface functionality of activated carbon thus enhancing the carbon dioxide (CO2) adsorption capacity. Green solvent is prepared by mixing an amino acid (L-Arginine) with ethylene glycol to form amino acid-based deep eutectic solvents. Amino acid-based deep eutectic solvents were used to modify the surface functionalities of activated carbon derived from palm shell waste. The change in surface functional groups and surface morphology of the modified activated carbon samples were characterized by Fourier-transform infrared spectroscopy and Scanning electron microscopy-energy dispersive X-ray analysis. Then, CO2 removal performance was performed using a packed-bed CO2 adsorption reactor to evaluate CO2 breakthrough time and adsorption capacity. CO2 adsorption experiments were measured at a certain temperature (25–45°C), at a fixed feed flow rate and CO2 concentration of 200 mL/min and 15%. It was observed that modified activated carbon showed the highest breakthrough time (15.2 min) compared to raw palm shell (5.2 min) at an adsorption temperature of 25°C. CO2 breakthrough times significantly decreased with increasing adsorption temperature because of physical adsorption.

Synthesis of a high-iron fly-ash-based Na-X molecular sieve and its application in the adsorption of low concentration of CO2.

In addressing the environmental challenges posed by the accumulation of fly ash (FA), efforts have been geared towards its high-value utilization. By the use of high-iron FA as a raw material, a high-iron fly-ash-based Na-X molecular sieve was successfully synthesized by hydrothermal method. We combined pretreatment methods such as high-temperature calcination, acid leaching and alkali fusion activation. The as-synthesized product was used for the adsorption of a low concentration of CO2, and the adsorption data were fitted by a physical model. The changes in iron content in pretreatment and molecular sieve synthesis were revealed by SEM-mapping, UV-Raman and UV-Vis. The results showed that the pretreatment process reduces the iron content from 32.3% to 13.3%, and converts the inactive phases to active phases, with n (SiO2/Al2O3) = 4.94. The activated product was transformed further to a Na-X molecular sieve using a hydrothermal method. The product has a single crystal phase and octahedral crystal structure. Its specific surface area was 646.634 m2 g-1, and micropores were distributed between 0.46 nm and 0.71 nm, with a mesoporous phase of 4.6 nm. When used to adsorb a low concentration of CO2, the Na-X molecular sieve has a high adsorption capacity of 3.70 mmol g-1, which reaches 95.11% that of the commercial Na-X molecular sieve. The adsorption breakthrough time and adsorption capacity decreased with an increase in temperature. The adsorption kinetics were consistent with the Bangham model for surface pore adsorption and Weber-Morris model for internal diffusion. During the synthesis process, iron was converted from highly dispersed iron oxide to four-coordinated framework iron. Thus, this paper paves a path for the high-quality transformation and utilization of high-iron fly-ash.

Artificial Neural Network [ANN] modeling for tetracycline adsorption on rice husk using continuous system

In this work, Tetracycline (TC) was dynamically adsorbed from aqueous solution using Raw Rice Husk (RRH). The removal of TC from various aqueous solutions was done continuously using a fixed bed column that was filled with RRH. It was investigated how various flowrates, bed heights, and TC concentrations impact the performance of the adsorption breakthrough. The dynamic TC adsorption process was modeled using an artificial neural network (ANN). Various error analysis techniques, such as the correlation coefficient, mean square error (MSE), and error histogram (R2) for the training, testing, and validation data, were employed to compare the model's predicted data with experimental data. The Artificial Neural Network (ANN) model that was utilized to predict TC adsorption using raw rice husk demonstrated a robust correlation coefficient of 0.999, This shows how well the trained model performed in predicting the TC adsorption process.

Anionic Ni-Based Metal-Organic Framework with Li(I) Cations in the Pores for Efficient C2H2/CO2 Separation.

Acetylene (C2H2) is widely used as a raw material for producing various downstream commodities in the petrochemical and electronic industry. Therefore, the acquisition of high-purity C2H2 from a C2H2/CO2 mixture produced by partial methane combustion or thermal hydrocarbon cracking is of great significance yet highly challenging due to their similar physical and chemical properties. Herein, we report an anionic metal-organic framework (MOF) named LIFM-210, which has Li+ cations in the pores and shows a higher adsorption affinity for C2H2 than CO2. LIFM-210 is constructed by a unique tetranuclear Ni(II) cluster acting as a 10-connected node and an organic ligand acting as a 5-connected node. Single-component adsorption and transient breakthrough experiments demonstrate the good C2H2 selective separation performance of LIFM-210. Theoretical calculations revealed that Li+ ions strongly prefer C2H2 to CO2 and are primary adsorption sites, playing vital roles in the selective separation of C2H2/CO2.

Study on the SO2 adsorption performance of dual-layer activated carbon cloth cathode air filter for high-power fuel cell

The removal of SO2 contaminant from the cathode air is crucial for the improvement of the efficiency of high-power fuel cell. The SO2 adsorption behaviour of dual-layer activated carbon cloth (ACC) was investigated at 5–15 ppm SO2 and filtration velocities of 0.125–0.45 m/s. The adsorption amount increased following a power function with time. The equilibrium breakthrough rate declines from approx. 88% to 56% when the concentration drops from 20 ppm to 5 ppm at 0.26 m/s and reduces from approx. 81% to 59% as the filtration velocity decreases from 0.45 m/s to 0.125 m/s at 10 ppm of SO2. In comparison to the packed bed filter, the pressure drop per thickness of the ACC media was considerably lower, measuring less than 9 Pa/mm, which can effectively decrease the parasitic power of the air supply unit. To determine filter’s breakthrough time and adsorption amount for the real application condition, a prediction method coupling the Yoon-Nelson model and the adsorption amount prediction model has been developed. The model can predict the breakthrough time and the adsorption amount of the full-scale filter using low-cost performance test data from the ACC materials with less than 10% error.

Uncharacteristic Adsorption Breakthrough Behavior of a Core–Shell Copper Hydroxysulfate Metal–Organic Framework Against Gaseous Formaldehyde

AbstractCore–Shell structured microspheres with a packed nano‐platelet copper hydroxysulfate (CHS) core and an octahedral crystalized metal–organic framework‐199 (CHS@M199) shell are synthesized and tested as adsorbent for gaseous formaldehyde (FA). CHS@M199 outperforms reference materials (e.g., activated carbon (AC), CHS, and M199) with adsorption capacity (Q) of 8.13 mg g−1 and partition coefficient (PC) of 0.263 mol kg−1 Pa−1 against 10 Pa FA at 10% breakthrough (BT) level with the aid of large surface area and copper sites for coordinating with carbonyl group. Contrary to general expectations, CHS@M199 exhibits a unique adsorption behavior in that BT volume increases systematically with the rise in FA inlet partial pressure (e.g., 5–10 Pa). The 10% BT capacity of CHS@M199 decreases noticeably (8.13 to 2.08 mg g−1) with increasing relative humidity (0.016 to 10%), reflecting water‐FA competition for hydrophilic adsorption sites. Although FA adsorption on CHS@M199 diminishes with elevated RH levels, such reduction intensifies when simulating ambient conditions (through stepwise addition of competing components: O2, CO2, and H2O). The FA adsorption on CHS@M199 is well described by both pseudo‐first‐order (PFO) and pseudo‐second‐order (PSO) kinetics. Polymerization may play a pivotal role in the adsorption of FA on CHS@M199, as Qi‐LeVan isotherm best fits the experimental data.

Assessment of the new kinetically limited linear driving force model for predicting diffusion limited adsorption breakthrough curves

Assessment of the new kinetically limited linear driving force model for predicting diffusion limited adsorption breakthrough curves

Combustion derived carbon with ultrahigh-mesoporosity and moderate surface affinity towards reversible low-volatile gas capture

Capturing naphthalene as a valuable chemical from waste gases via adsorption on porous sorbent materials is a promising approach to tackle such an environmental health issue with additional economic benefits. However, very few sorbents have simultaneously high adsorption capacity and good regenerability for the large-molecular and low-volatile naphthalene. Here we attempt to address this challenge by integrating key fabrication elements of a layer-by-layer network, rational mesoporosity, and highly reversible sites into a carbonaceous adsorbent (ECSC) using a facile and fast eruptive solution combustion synthesis method. Adsorption breakthrough and temperature-programmed desorption experiments show that the ECSC achieves all-round superior naphthalene capture performance with unprecedented high capacity, fast kinetics, and low desorption energy. The combination of in situ DRIFTS, XPS, and DFT calculations reveals the moderate adsorption affinity of mitigated π–π stacking bonding between tilted naphthalene molecule and surface pyridinic N. This work affords new insights for designing next-generation adsorbents for naphthalene removal and presents a way of overcoming the adsorption–desorption dilemma for gas purification.

Cu-Zn interaction regulating via heat treatment and the ultra-deep desulfurization for thiophene over Cu/ZnO sorbent

The ultra-deep removal of thiophene is a necessary process for the coke oven gas (COG) to methane technology via methanation. It is usually carried out using copper-zinc (Cu-Zn) based sorbent, which was reported to has excellent desulfurization performance, however the effect of Cu-Zn interaction on the desulfurization activity of the sorbent is still need to be further understood. Here, the sorbent precursor was prepared via co-precipitation method, and it was treated at different temperatures to obtain a series of sorbents with different Cu-Zn interaction. The fixed bed reactor was used to evaluate the desulfurization performance, the XPS and H2-TPR was carried out to determine the Cu-Zn interaction in sorbents, and the N2 adsorption, XRD, N2O adsorption, FT-IR were used to characterize the physical and chemical properties of samples. The results show that the Cu-Zn interaction could be effectively controlled by heat treatment temperature. At 300 °C, the sorbent precursor would be easily transformed into Cu-Zn solid solution, where the Cu-Zn interaction is strong, and the dispersion of Cu on the sorbent surface is maximized (16.0 %). Those greatly increase the desulfurization activity, and the breakthrough adsorption capacity for thiophene could reach up to 25.1 mg/g. At 250 °C, the temperature is not enough for the transforming of sorbent precursor into Cu-Zn solid solution, so that the breakthrough adsorption capacity for thiophene is only 12.4 mg/g. Whereas, when the temperature is higher than 350 °C, the Cu-Zn solid solution would be further transformed into CuO and ZnO, which significantly decreases the desulfurization activity. In addition, the density functional theory (DFT) calculation results provide further evidence that strong Cu-Zn interaction is beneficial to the desulfurization behavior of sorbent. This work provides both theoretical guidance for promoting the desulfurization performance of copper-based sorbents.

Adsorption behavior and mechanism of ethyl mercaptan in natural gas on Cu-modified hexaniobate nanotubes

The presence of sulfur compounds in natural gas seriously affects the yield of hydrogen production from natural gas reforming and the lifespan of catalysts. This study aims to clarify the characteristics and mechanism of the removal of ethyl mercaptan (EM) in equilibrium CH4 by Cu-modified hexaniobate nanotubes (Cu-HNT-450), which was synthesized through a method of copper ions exchange-flocculation-calculation. The EM breakthrough adsorption experiments and the valence state of copper and the types of sulfur on Cu-HNT-450 during dynamic tests were investigated. The removal of EM is mainly achieved through the chemical adsorption of CuO, Cu2O and oxygen on Cu-HNT-450. In the process of EM removal, catalytic oxidation, sulfonate formation and reactive adsorption lead to the formation of sulfide, copper sulfonate and copper thiolate, respectively. Cu-HNT-450 has the highest breakthrough adsorption capacity for EM, reaching 103.6 mg/g at 50 °C. The exhausted Cu-HNT-450 can also be regenerated by thermal treatment at different temperatures under nitrogen atmosphere. However, due to the strong chemical adsorption of sulfur containing compounds, the recovery of nitrogen thermal regeneration removal efficiency is limited. This research work provides guidance for the design of mercaptans removal catalysts and deepens the understanding of the reaction mechanism of mercaptans removal.

Modulation of pore structure in a microporous carbon for enhanced adsorption of perfluorinated electron specialty gases with efficient separation

Physical adsorption-based separation and recovery of perfluorinated electron specialty gases from N2 contribute to reducing the greenhouse effect and increasing economic value in the electronics industry. Commercial activated carbon materials are promising adsorbents for the practical application due to the industrial-scale production, while they usually characterize an unsatisfactory micropore structures, and the rational modulation to meet the requirement of fluorinated gas adsorption is in demand. In this work, a series of KOH-treated commercial activated carbon (ACK) with KOH/carbon mass ratios of 1 ∼ 4 were systematically characterized and evaluated for adsorptive separation of SF6, NF3, and CF4. Characterization results reveal that KOH treatment largely promotes the modulation of pore structure and results in the extremely narrow pore size distribution at 0.5 ∼ 0.9 nm, highest microporosity of 97.6 % in the optimal ACK1, which are ascribed to etching effect of KOH on carbon framework. Static adsorption results indicate that a simultaneous enhancement in gas uptake and separation selectivity is found in ACK1 compared to the parent AC for all the studied fluorinated gases. Importantly, ACK1 performs a high SF6 uptake of 3.10 mmol·g−1 and the record SF6/N2 selectivity of 683.9 (298 K, 100 kPa) among the reported carbon adsorbents, which is comparable to the top-performing MOFs material. The kinetic adsorption and dynamic breakthrough experiments further verify the fast adsorption rate, excellent separation performance of SF6/N2, and recyclability of ACK1 adsorbent. These findings expand the promising application of commercial AC in the adsorption-based separation of perfluorinated electron specialty gases including SF6, NF3, and CF4.

Breakthrough curve modeling for lysozyme by ion-exchange nanofiber membrane: Linear and nonlinear analysis

BackgroundNanofibers prepared by electrospinning technology are widely used as an adsorber in protein purification processes. However, the evaluation of dynamic adsorption performance has not been reported yet. MethodsLysozyme was subjected to assess dynamic adsorption of weak ion exchange nanofiber membranes by applying a continuous flow system. Different operating conditions were selected to study the lysozyme adsorption breakthrough curve, which included four factors: pH, feedstock lysozyme concentration, feed flow rate, and stacked membrane layers. The breakthrough curve was applied to analyze the performance for dynamic binding with lysozyme as a model protein. In addition, the adsorption models (Bohart-Adams, Thomas, Yoon-Nelson, and BDST) were fitted to the breakthrough curves using linear and nonlinear regression analysis. Significant findingsIt was found that the four operating parameters had considerable influences on the dynamic adsorption performance. Among these models, the breakthrough curve was well-fitted by using linear regression analysis of the Yoon-Nelson model. The breakthrough curve characteristics could be used to describe the dynamic binding performance of interested membranes to lysozyme molecules.