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Ethylene dimerization is an efficient industrial chemical process to produce 1‐butene, with demanding selectivity and activity requirements on new catalytic systems. Herein, a series of monodentate phosphinoamine‐nickel complexes immobilized on UiO‐66 are described for ethylene dimerization. These catalysts display extensive molecular tunability of the ligand similar to organometallic catalysis, while maintaining the high stability attributed to the metal–organic framework (MOF) scaffold. The highly flexible postsynthetic modification method enables this study to prepare MOFs functionalized with five different substituted phosphines and 3 N‐containing ligands and identify the optimal catalyst UiO‐66‐L5‐NiCl2 with isopropyl substituted nickel mono‐phosphinoamine complex. This catalyst shows a remarkable activity and selectivity with a TOF of 29 000 (molethyl/molNi/h) and 99% selectivity for 1‐butene under ethylene pressure of 15 bar. The catalyst is also applicable for continuous production in the packed column micro‐reactor with a TON of 72 000 (molethyl/molNi). The mechanistic insight for the ethylene oligomerization has been examined by density functional theory (DFT) calculations. The calculated energy profiles for homogeneous complexes and truncated MOF models reveal varying rate‐determining step as β‐hydrogen elimination and migratory insertion, respectively. The activation barrier of UiO‐66‐L5‐NiCl2 is lower than other systems, possibly due to the restriction effect caused by clusters and ligands. A comprehensive analysis of the structural parameters of catalysts shows that the cone angle as steric descriptor and butene desorption energy as thermodynamic descriptor can be applied to estimate the reactivity turnover frequency (TOF) with the optimum for UiO‐66‐L5‐NiCl2. This work represents the systematic optimization of ligand effect through combination of experimental and theoretical data and presents a proof‐of‐concept for ethylene dimerization catalyst through simple heterogenization of organometallic catalyst on MOF. [ABSTRACT FROM AUTHOR]

Polar stationary phases were prepared by grafting hydrophilic acrylamide (Am) polymer brushes with post modification of carbon dots (CDs) and silicon dots (SiDs) onto SiO2 particles. The prepared stationary phases, SiO2-PAm-CDs, SiO2-PAm-CDs/SiDs, and SiO2-PAm-SiDs, were packed as chromatographic columns, respectively. Using nucleic bases, organic acids, and β-agonists as target substances to investigate the influence of chromatographic conditions on retention and separation, the packed columns showed the partitioning and adsorption of mixed retention behavior in hydrophilic interaction liquid chromatography mode and successfully separated the polar compounds. Most importantly, under per aqueous liquid chromatography mode (using 100% water as mobile phase), those columns still had good separation ability toward nucleic bases, β-agonist, and organic acids. Because AM is a temperature-sensitive monomer, the resulting van't Hoff curves exhibited a nonlinear relationship, having temperature-responsive chromatographic characteristic under pure water separation. Hence, building on temperature-sensitive characteristics and pure water of separation conditions, the separation selectivity toward hydrophilic compounds greatly improved. Compared with the commercial hydrophilic columns, the efficiency of our developed column had the superior ability in separation and detection of betaine in Goji berry with the enhanced resolution achieved in the proposed green separation method (just using pure water as mobile phase). [ABSTRACT FROM AUTHOR]

Gelatin-based aerogel (G-Aerogel) from untanned proteinaceous solid wastes was applied as an adsorbent in batch and fixed-bed column systems to remove acid red 97 (AR97) from water. Adsorption was evaluated as a function of pH, adsorbent mass, contact time, temperature, and initial dye concentration. Maximum removal of AR97 was achieved at pH 3 after about 4 h. The pseudo-second-order equation provided the best adsorption kinetic model. The adsorption of AR97 onto G-Aerogel was best described with the Langmuir model, and the maximum adsorption capacity was about 196 mg·g−1. A thermodynamic study showed an exothermic and spontaneous adsorption process. It was also demonstrated that G-Aerogel can be reused several times. The column study showed that breakthrough and saturation times decreased with increasing initial AR97 concentration. Thomas and Yoon-Nelson kinetic models were applied to the experimental data to predict the breakthrough curves and determine the characteristic parameters of column adsorption. Practical Applications: Tannery solid wastes composed mainly of collagen are very abundant and constitute a material that should be valorized. In this study, we examined the transformation of untanned proteinaceous wastes into a biomaterial [Gelatin-based aerogel (G-Aerogel)] of environmental interest. The results demonstrated the promise of this material for dye adsorption because of its advantages in terms of its ease of preparation, its containing functional groups that are able to attract dye, its ability to be reused several cycles, and its high adsorption capacity. In addition to studying adsorption in static mode, we also studied dynamic adsorption, because the common industrial practice is to pass water to be treated through a column packed with an adsorbent, allowing the transport of the pollutant from the liquid to the solid. In summary, G-Aerogel can be applied as an environmentally friendly and efficient adsorbent for the removal of dyes from contaminated water. [ABSTRACT FROM AUTHOR]

The effluents from pulp and paper manufacturing industries contain high concentrations of phenol, which when discharged directly into surface water streams, increases the biological oxygen demand (BOD) and chemical oxygen demand (COD). In this study, two dominant bacteria SP-4 and SP-8 were isolated from the effluent emanating with a pulp and paper industry. The selected phenol-degrading isolates were identified as Staphylococcus sp. and Staphylococcus sciuri respectively by using nucleotide sequence alignment and phylogenetic analysis of 16 S rRNA regions of the genome. The two isolates used for the biodegradation process effectively degraded phenol concentration of pulp and paper industry effluent upto 1600 and 1800 mg/L resepctively. The individual isolates and consortium were immobilized using activated carbon, wood dust, and coal ash. Additionally, the effluent was treated using a bio-filter tower packed column immobilized with bacterial cells at a constant flow rate of 5 mL/min. The present study showed that the developed immobilized microbial consortium can effectively degrade 99% of the phenol present in pulp and paper industry effluents, resulting in a significant reduction in BOD and COD of the system. This study can be well implemented on real-scale systems as the bio-filter towers packed with immobilized bacterial consortium can effectively treat phenol concentrations up to 1800 mg/L. The study can be implemented for bioremediation processes in phenolic wastewater-contaminated sites. [ABSTRACT FROM AUTHOR]

Extensive experimental research and hydrodynamic models have been proposed to guide the design of superior packings. However, most research has concentrated on the effective void (ε − H) of packing while ignoring the ineffective void (ε − H − HL), which causes discrepancies in hydrodynamic performance compared to actual observations. This study evaluated the hydrodynamic performance under diverse conditions considering the liquid holdup (H), pressure drop (ΔP), and gas flooding velocity (uf). A novel approach to hydrodynamic model construction is introduced by incorporating an ineffective void. The results indicate that at a constant hold‐up area, liquid flow (L) and viscosity (μ) significantly influence liquid hold up, moderated by the gas velocity in the flooding area. The pressure drop rises as the viscosity, gas flow rate, and liquid flow rate increase. Notably, a considerable pressure drop initiates flooding at the bottom of the absorber. Elevated liquid flow rates and viscosities correlate with higher ineffective void values (HL) in the packing column. At low gas flow rates, the gas flow rate marginally affects HL values. However, after the flooding point was achieved, the values of HL rapidly increased as the gas flow rate increased. Moreover, a linear relationship emerges between the liquid holdup and HL, as evidenced by the consistent variation in the liquid holdup and the F‐factor. Utilizing the ineffective void yields a more accurate fit for the experimental data, reducing the average absolute relative deviation to 10.2%, 7.4%, and 10.8%, respectively. [ABSTRACT FROM AUTHOR]

Fiber-reinforced polymer (FRP) wraps of reinforced concrete columns might be vulnerable to accidental damage or vandalism. This study aims to develop a simple empirical tool that is based on experimental results to aid in the condition assessment and establish the reduced axial strength ratio (P/Po) of short columns that are loaded at small eccentricities. A total of 47 cylinders, 152 mm in diameter (D), were wrapped with carbon–FRP sheets of 1–3 layers [i.e., producing confinement effectiveness (fcc′/fc′) of 2.3–4.0] and were then subjected to a vertical cut of length (x) that varied from 0.20D to 0.61D at midheight. The loading eccentricity (e) varied from zero to 0.1D. The cut location around the perimeter, for the angle (θ) that was measured from the point of extreme compression, was varied from 0° to 180°. The jacket cuts affect eccentrically loaded cylinders more severely than concentrically loaded ones. As e increased from zero to 0.1D, P/Po reduced from 1.0 to 0.81 for intact samples and from 0.56 to 0.40 for samples with jacket cut. As the cut location traveled around the circumference starting from extreme compression (θ = 0°), less strength reduction was observed where P/Po increased, and at θ = 180° it even exceeded P/Po at zero eccentricity. This suggests a reduction in eccentricity due to a shift in the cross-sectional centroid due to the disturbed confinement on one side. Design models that account for e/D, θ, x/D, and inclined cuts have been developed and calibrated for cylinders of up to 22 slenderness ratio. In addition, a design example is presented. [ABSTRACT FROM AUTHOR]

Molecularly imprinted polymer (MIP)-based chromatographic separation materials, owing to their advantages of unique selectivity, low cost, suitable reproducibility, and acceptable stability, have attracted a great deal of research in different fields. In this investigation, a new type of MIP-coated silica (MIP/SiO2) separation material was developed using sulfamethoxazole as a template; the specific recognition ability of MIP and appropriate physicochemical properties (abundant Si-OH, suitable pore structure, good stability, etc.) of SiO2 microbeads were combined. The MIP/SiO2 separation materials were characterized carefully. Then, various compounds (such as sulfonamides, ginsenosides, nucleosides, and several pesticides) were used to comprehensively evaluate the chromatographic performances of the MIP/SiO2 column. Furthermore, the chromatographic performances of the MIP/SiO2 column were compared with those of other separation materials (such as non-imprinted polymer-coated silica, C18/SiO2, and bare silica) packed columns. The resolution value of all measured compounds was more than 1.51. The column efficiencies of 13 510 plates per meter (N m−1) for sulfamethoxazole, 11 600 N m−1 for ginsenoside Rd, and 10 510 N m−1 for 2′-deoxyadenosine were obtained. The acceptable results verified that the MIP/SiO2 column can be applied to separate highly polar drugs such as sulfonamides, ginsenosides, nucleosides, and pesticides. [ABSTRACT FROM AUTHOR]

The hydraulic calculation of column internals is crucial for their design. The various fouling effects (due to crystallization, particles, chemical reaction) influence the hydraulics of columns in different ways (capacity, separation efficiency). However, current hydraulic models are based on clean systems and do not consider fouling. By properly taking into account the geometrical parameters affected by fouling, the classical models can be used to calculate the state of internals as they evolve over time. [ABSTRACT FROM AUTHOR]

Liquid-solid fluidized bed (LSFB) sorting has been widely used in coarse coal slurry sorting in coal preparation plants in China. In this paper, the vertical distribution of high-ash fine sludge in the LSFB column was studied in depth, and the results showed that in the vertical direction of the column, the gradient of ash change of the + 0.25 mm particles was obviously larger than that of the −0.25 mm particles. For + 0.25 mm particles, the low-density fine coal particles accumulate in the middle and upper parts, while the high-density particles accumulate in the middle and lower parts, and the overflow −0.25 mm particles are basically uniformly distributed in each density class. In the overflow port and the upper part of the column, the ash content of −0.25 mm particle size is obviously higher than that of + 0.25 mm particle size, and the −0.125 mm high ash and fine sludge basically accumulate in the upper part of the LSFB, and eventually enter the overflow to seriously pollute the fine coal. This study is of great significance for the development and application of LSFB sorting machine and the optimization of coarse coal slurry sorting and recovery process. [ABSTRACT FROM AUTHOR]

This study explored the adsorption of acetaminophen and caffeine using CO2-activated biochar (BT-CO2) and hydrochar (HT-CO2) derived from Tingui shell biomass. The experimental data from kinetic and equilibrium adsorption tests were employed in batch and fixed-bed systems. In the batch system, a specific amount of the adsorbent was added to a known volume of the solution, and the mixture was agitated for a set period to allow adsorption to occur. In the fixed-bed system, the solution was passed through a column packed with the adsorbent, allowing for continuous adsorption. These systems pave the way for future research. The findings revealed that HT-CO2 exhibited a greater surface area and a higher presence of oxygen-containing functional groups than BT-CO2. These functional oxygen groups had a notable impact on the adsorption capacity of the adsorbents for pharmaceutical substances. In the batch systems, BT-CO2 demonstrated a maximum adsorption capacity of 221.4 mg g−1 for acetaminophen and 162.7 mg g−1 for caffeine, while HT-CO2 exhibited higher capacities of 383.2 mg g−1 for acetaminophen and 189.7 mg g−1 for caffeine. In the fixed bed configuration, HT-CO2 displayed a maximum adsorption capacity of 82.2 mg g−1 for acetaminophen and 45.60 mg g−1 for caffeine. The predominant mechanisms involved in the removal of acetaminophen and caffeine were identified as H-bonding and π-π bonds. These results underscore the promising potential of these carbons as effective adsorbents for treating water contaminated with pharmaceutical residues, inspiring further exploration in this field and offering hope for the future of water treatment by providing a solid foundation for future research and development. [ABSTRACT FROM AUTHOR]

Wetted wires are a unique column internal with several advantages compared to spray and packed columns. These include near-perfect liquid distribution, extremely low pressure drops, and better heat or mass transfer due to droplet circulation. Currently, wetted-wire columns remain within the laboratory prototyping stage. The primary goal of this review is to present the current research on wetted-wire columns and to highlight the gaps that impede scale-up and commercialization. Initially, wetted-wire columns were proposed as an alternative to spray towers. However, wetted-wire columns occupy a space in between spray towers and packed columns. Therefore, wetted-wire columns should also be analyzed more like packed columns to increase the speed of technological translation. Wetted-wire column literature is presented by defining features (wire diameter, nozzle diameter, pitch, and material) and by performance indicators (operating range, pressure drop, hold-up, and separation efficiency). In addition, adjacent literature on wire-like structures is discussed. [ABSTRACT FROM AUTHOR]

This mobility study aimed to determine the transport of TiO2 NPs from topsoil to deeper zones. The saturated soil column method imitated TiO2 NPs transport in real-world conditions and possible leaching scenarios. Three soils were studied: City soil (SCity), Agricultural (SAgri), and Sand. This investigation used ICP-OES, EDX, SEM and DLS to determine TiO2 NPs sizes, track the mobility patterns and quantify them in soil layers. The results have revealed that the mobility and retention of TiO2 NPs were highly influenced by Clay, organic matter (OM), and CEC. The concentration of TiO2 NPs in the deepest soil layers and the breakthrough water was low in SCity, in which Clay and OM were high. In contrast, TiO2 NPs were relatively high in the lowest layers of SAgri, where the Clay and OM content was insignificant. The columns packed with Sand showed the highest transported of TiO2 NPs where Clay and OM were absent. The breakthrough water obtained from Sand columns showed the highest TiO2 NPs concentration, followed by SAgri and SCity. The columns packed with SCity had more TiO2 NPs retention due to the presence of CEC in Clay and OM. This investigation showed that the transport of TiO2 NPs in the soil at low concentrations is a fact. It depends on soil properties such as texture, OM content, pH, and CEC. [ABSTRACT FROM AUTHOR]

The use of natural zeolite clinoptilolite to reduce the leaching rate of potentially toxic elements such as Cd, Pb, and Mn in soil from mine tailings was studied. Soil from the surroundings of the mine El Bote in Zacatecas, Mexico, was analyzed, and the zeolite was characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, and nitrogen physisorption. An ammonium-exchange method for the zeolite was employed. Leaching experiments using packed columns with polluted soil and zeolite mixtures were carried out and the effect of the pH of the carrier solutions was studied. Incorporation of zeolite in the soil achieved a beneficial increase in pH, from 5.03 to 6.95. The concentration of Cd and Mn was reduced when zeolite was present in the column and the ammonium-modified zeolite with ammonia also enhanced the concentration reduction of metallic species in leachates in a range of 28 to 68%. The first-order model best fits the experimental data, suggesting that the leaching rate is controlled by concentration difference between the liquid and the soil matrix. These results demonstrate the potential for using natural zeolite clinoptilolite to reduce the leaching rate of potentially toxic elements in soil from mine tailings. [ABSTRACT FROM AUTHOR]

In this work, a chiral core-shell microspheres composite, L-his-MIL-53-NH2@SiO2, was prepared through in situ growth and chiral post-modification strategies. The core-shell microspheres were applied as a novel chiral stationary phase for HPLC enantiomeric separation. Various racemates were separated on the L-his-MIL-53-NH2@SiO2 packed column using n-hexane/isopropanol as the mobile phase. The chiral column showed excellent separation efficiency for fourteen chiral compounds, including alcohols, alkanes, esters, phenols, ketones, and organic acids. The influence of injection mass and temperature on the separation performance of the chiral column were investigated. The relative standard deviations (n = 5) of the retention time and peak area by repeated separation of benzoin are 0.28% and 0.63%, respectively. The results show that the L-his-MIL-53-NH2@SiO2 packed column exhibited good reproducibility and stability. In addition, the chiral resolution ability of the L-his-MIL-53-NH2@SiO2 packed column was compared with that of a commercial chiral column (Chiralpak AD-H). The L-his-MIL-53-NH2@SiO2 packed column exhibits unique advantages in chiral separations that can be complementary to the commercial chiral column. It was demonstrated that the chiral core-shell microspheres composite L-his-MIL-53-NH2@SiO2 prepared based on in situ growth and chiral postmodification strategies has great potential for enantiomeric separation by HPLC. [ABSTRACT FROM AUTHOR]

The decontamination of wastewater is an important issue for the nuclear industry. The removal of Sr2+, one of the most problematic radioelements, requires hierarchical materials suitable for fixed-bed processes. This article describes a patented emulsion-templating route for the synthesis of Linde Type A (LTA) zeolite-geopolymer composites with a multiscale porosity. By dispersing zeolite particles in an emulsion oil-in-water containing precursors of geopolymer, LTA zeolite–geopolymer composites can be obtained after curing and eliminating the oil phase. The zeolite particles alter the macroporous structure of the materials (replicating the oil droplets) as well as the size of the mesopores of the geopolymer binder. Moreover, zeolite contents higher than 30 wt% induce a crumbling of the material structure. The presence of LTA zeolite particles increases the selectivity of the composites for Sr2+ in very saline media, while the porous network of the material ensures rapid adsorption. The optimal composite prepared here outperformed a commercial sorbent for the Sr2+ decontamination of a saline wastewater through a packed column. • Geopolymer-zeolite composites were synthesized through an emulsion-templating route. • The zeolite weight percentage in the composite strongly influences its microstructure. • Increasing the amount of zeolite in the material increases its selectivity for Sr2+. • Geopolymer-zeolite composites are well adapted to be used in fixed bed process. [ABSTRACT FROM AUTHOR]

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The Elastic Catalytic Foam-bed Reactor (EcFR) technology was used to enhance a model catalytic hydrogenation reaction by improving gas–liquid mass transfer. This advanced technology is based on a column packed with a commercial elastomeric polyurethane open-cell foam, which also acts as a catalyst support. A simple and efficient crankshaft-inspired system applied in situ compression/relaxation movements to the foam bed. For the first time, the catalytic support parameters (i.e., porosity, tortuosity, characteristic length, etc.) underwent cyclic and controlled changes over time. These dynamic cycles have made it possible to intensify the transfer of gas to liquid at a constant energy level. The application chosen was the selective hydrogenation of phenylacetylene to styrene in an alcoholic solution using a palladium-based catalyst under hydrogen bubble conditions. The conversion observed with this EcFR at 1 Hz as cycle frequency was compared with that observed with a conventional Fixed Catalytic Foam-bed Reactor (FcFR). [ABSTRACT FROM AUTHOR]

There is growing demand for separation of 90Y carrier free from 90Sr coexisting to produce high purity 90Y essential for radiopharmaceutical uses. Thus, in this context the sorption profiles of Y3+ and Sr2+ from aqueous solutions containing diethylenetriaminepenta acetic acid (DTPA), ethylenediaminetetra-acetic acid (EDTA), acetic acid, citric acid, or NaCl onto Chelex-100 (anion ion exchange) solid sorbent were critically studied for developing an efficient and low-cost methodology for selective separation of Y3+ from Sr2+ ions (1.0 × 10−5 M). Batch experiments displayed relative chemical extraction percentage (98 ± 5.4%) of Y3+ from aqueous acetic acid solution onto Chelex-100 (anion ion exchanger), whereas Sr2+ species showed no sorption. Hence, a selective separation of Y3+ from its parent 90Sr2+ has been established based upon percolation of the aqueous solution of Y3+ and Sr2+ ions containing acetic acid at pH 1-2 through Chelex-100 sorbent packed column at a 2 mL min−1 flow rate. Y3+ species were retained quantitatively while Sr2+ ions were not sorbed and passed through the sorbent packed column without extraction. The sorbed Y3+ species were then recovered from the sorbent packed column with HNO3 (1.0 M) at a 1.0 mL min−1 flow rate. A dual extraction mechanism comprising absorption associated to "weak-base anion exchanger" and "solvent extraction" of Y3+ as (YCl6)3− and an extra part for "surface adsorption" of Y3+ by the sorbent is proposed. The established method was validated by measuring the radiochemical (99.2 ± 2 1%), radionuclide purity and retardation factor ( R f = 10.0 ± 0.1 cm) of 90Y3+ recovered in the eluate. Ultimately, the sorbent packed column also presented high stability for reusing 2-3 cycles without drop in its efficiency (±5%) towards Y3+ uptake and relative chemical recovery. A proposed flow sheet describing the analytical procedures for the separation of 90Y3+ from 90Sr2+ using chelating Chelex 100 (anion exchange) packed column is also included. [ABSTRACT FROM AUTHOR]

It is imperative to minimize radioiodine release to the environment through gaseous emissions of spent fuel reprocessing facilities, thereby mitigating its potential impact on the general public. One effective and widely adopted strategy for achieving this objective is caustic scrubbing, a method that involves the absorption of molecular iodine from gaseous streams using caustic soda ( NaOH ) solution in a packed column. In-depth laboratory-scale experiments were conducted to ascertain the overall volumetric mass transfer coefficient K G a for the absorption of dilute iodine vapor from air into a caustic soda solution in a packed column and to establish optimum performance parameters for this process. The investigation yielded noteworthy findings: K G a increased proportionately to (Gas phase Reynolds number)1.0 at constant liquid flow rates across all types of packing tested. K G a displayed relative independence from liquid velocities for high and moderate NaOH concentrations. However, this coefficient varied proportionately to (Liquid phase velocity)0.26 to 0.42 at lower NaOH concentrations under conditions of high gas flow rates NaOH . As the height of the column increased, K G a was found to decrease slightly. The presence of NOx at an inlet concentration of 9000 ppm in the gaseous stream led to a reduction in the mass transfer coefficient of iodine, particularly at low NaOH concentrations. In summary, the study underscores the importance of caustic scrubbing as an effective means to minimize the release of radioiodine. The investigation's results provide valuable insights into optimizing performance parameters for this process, contributing to enhanced environmental protection. [ABSTRACT FROM AUTHOR]

Background: The level of bacteremia in patients with sepsis and septic shock is a predictor of complications and mortality, regardless of the type of bacteria. Devices for bacteria, endotoxin and cytokines removal by adsorption have been recently developed. Thus, extracorporeal blood purification therapies have been proposed as adjunctive therapy in sepsis in combination with drugs. Some potentially useful drugs, however, are precluded due to their organ or metabolic toxicity. The present study represents a preliminary report on the in vitro effect of a sorbent device (minimodule with HA380 beads, Jafron medical, Zhuhai, China) in which the particles have been functionalized with vancomycin on the surface. The impact of the surface‐modified beads on circulating bacteria (Staphylococcus aureus) has been tested in a simulated in vitro circulation. Methods: In vitro experiments were carried out with 800 mL of blood enriched with S. aureus species. Blood was circulated in the vancomycin‐functionalized and non‐functionalized mini‐module cartridges in hemoadsorption setup (300 mL each) and the bactericidal effect was assessed. Also, 200 mL of blood was used as a control. Results: A significant increase in the time to positivity of blood cultures was observed after 60 min and also after 120 min of therapy with the mini‐module functionalized with vancomycin as opposed to the non‐functionalized cartridge. Conclusions: These results suggest a possible way of treating sepsis by using drug‐ or antibiotic‐functionalized cartridges without worrying about pharmacological toxicity. The prolongation of the time to bacterial culture positivity to S. aureus after a passage through a column packed with beads functionalized with vancomycin represents a proof of concept. [ABSTRACT FROM AUTHOR]

The arsenic adsorption performance of silicon (Si), iron (Fe), and magnesium (Mg) mixed hydrous oxide containing a Si: Fe: Mg metal composition ratio of 0.05:0.9:0.05 (SFM05905) was investigated. SFM05905 was synthesized by the co-precipitation method. Batch experiments on arsenic adsorption were conducted at various temperatures and concentrations. Adsorption isotherms models were represented by a linearized equations and were insensitive to temperature change. The anion selectivity of SFM05905 at single component was high for arsenite (III), arsenate (V), and phosphate (PO4), indicating that PO4 inhibits arsenic adsorption. The adsorption amount of As (III), As (V), and PO4 were compared using a column packed with granular SFM05905, and an aqueous solution was passed by a combination of several anions that are single, binary, and ternary adsorbate systems. As (III) had the highest adsorption amount; however, As (III) and PO4 were affected by each other under the ternary mixing condition. Although the adsorption amount of As (V) was smaller than that of As (III), it was not affected by other adsorbates in the column experiments. Finally, although the adsorption of both arsenic continued, the adsorbed PO4 gradually desorbed. [ABSTRACT FROM AUTHOR]

Solution to the high pressure drop in the dry gas desulfurization tower of a certain company' s liquid phase diesel hydrogenation unit was introduced. The main measures to control the pressure drop of dry gas desulfurization tower are determined through the combination of Storks law theory analysis and experiments, including reducing the flow rate of sulfur-containing dry gas and solving the problem of packing layer blockage. The results show that if the sulfur-containing dry gas flow rate was reduced from 7,600 m³/h to 6,500 m³/h, the pressure drop of the dry gas desulfurization tower was decreased by 6. 5 kPa, and the effect was poor. The blockage of the filling layer is mainly due to the large amount of high carbon solid particles in the upstream lean amine solution, which suspend and settle in the lean amine solution. According to Storks law and utilizing this drag force characteristic, the settling speed of solid black particles is 0. 012 m/s. Therefore, through the full tower operation, the lean amine solution inside the packing tower was quickly sent out, and the high-speed flow generated drag force opposite to settlement, which was enough to suspend it and remove a large number of high carbon solid particles from the packing. The pressure drop of the dry gas desulfurization tower was quickly decreased from 53 kPa to 1 kPa. The problem of high pressure drop caused by blockage of high carbon solid particles in the packing layer was solved, with strong operability and significant effects. [ABSTRACT FROM AUTHOR]

The paper presents the estimate of hydrodynamic parameters of the gas phase motion at low-temperature fractionation of boron trifluoride in a packed column. The following parameters are detected: density and viscosity for reacting phases in the operational temperature range, gas velocity at the phase inversion point, Reynolds number, and retention capacity for the investigated types of packed beds. Using the Logos software, numerical simulation of gas velocity and pressure distribution in the packed bed is performed for fractionation of boron trifluoride. [ABSTRACT FROM AUTHOR]

The current study aims to assess the performance and industrial feasibility of using three-phase fluidized bed absorption columns for post-combustion carbon dioxide (CO 2) capture. The analysis is based on a mathematical model of a scaled-up fluidized bed absorption column that has been validated using pilot plant experimental data. The focus is on evaluating the energy efficiency of the fluidized bed column in comparison to packed bed technologies, which are currently widely used. The results of the analysis are evaluated in terms of three performance indicators (i.e., absorption efficiency, carbon capture rate, and energy performance index) and compared to packed bed columns. Simulation results indicate that the best column configuration is represented by a three-stage absorber and that the system performs optimally when particle diameter and density decrease with each section. Consequently, this leads to an increase in the total fluidized bed height and carbon capture rate by up to 25%. The energy performance index is maintained below 3.6, indicating an energy-efficient operation of the system. As such, the findings of this study suggest that the use of gas-solid-liquid three-phase fluidized bed absorption columns for post-combustion CO 2 capture is a promising technology for the implementation of CCUS and for achieving of climate neutrality targets. [Display omitted] • Mathematical modeling through experimental assessment. • Consideration of a three phase, gas-solid-liquid, fluidized bed absorber for carbon capture. • Integration of gas-solid-liquid fluidized bed absorber in a full-scale carbon capture plant. • Performance analysis of three phase absorption in terms of energy and carbon capture efficiency. • Comparison of the obtained performance with the one obtained using regular packed bed absorbers. [ABSTRACT FROM AUTHOR]

Continuous flow chemistry has become the method of choice for the synthesis of toxic and explosive intermediates such as diazo reagents because they can be generated on demand and readily used, eliminating the need to handle hazardous materials. This inherent increase in safety makes it more feasible to use these reagents in day-to-day synthesis. Herein, we describe a continuous flow, metal-free, easy-to-use method for the preparation of semi-stabilized and unstabilized diazo reagents. The scope of the described continuous flow oxidation of hydrazones using a packed bed column with iodosylbenzene includes 13 semi-stabilized and 13 unstabilized diazo reagents in solution in dichloromethane while producing only 1 equivalent of water and iodobenzene as by-products. These otherwise difficult to access compounds are further reacted either in situ or at the reactor outlet to yield esters and ethers in good to excellent yields (47–96%). [ABSTRACT FROM AUTHOR]

This work investigates the incorporation of sodium dodecyl sulfate (SDS) onto activated carbon made from coconut shells to improve the removal of Pb (II) or Cu (II) from synthetic wastewater in a packed column. The activated carbons were characterized using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy-energy dispersive x-ray (SEM-EDX). The column dynamics were studied to calculate its performance. The adsorption data were fitted into the Thomas, Yoon-Nelson, and Adams-Bohart models. The activated carbon has a pore volume of 0.453 cm3/g and a BET-specific surface area of 513 m2/g. The incorporation of SDS surfactant onto the surface of the activated carbon (AC) significantly enhances the removal of Pb (II) and Cu (II) from synthetic wastewater in a packed column. An increase in flow rate or initial metal concentration decreases break-through and exhaustion time, while an increase in bed height increases break-through and exhaustion time. When the bed height increased from 5 to 20 cm, the Yoon-Nelson adsorption constant (KYN) increased from 0.0324 to 0.0372 (1/min) for the Pb (II)-AC-SDS system, while KYN increased from 0.0293 to 0.0353 (1/min) for the Cu (II)-AC-SDS system. The adsorption data only fit well into the Thomas and Yoon-Nelson models. [ABSTRACT FROM AUTHOR]

Fugitive methane emissions from the mining industry, particularly so-called ventilation air methane (VAM) emissions, are considered among the largest sources of greenhouse gas (GHG) emissions. VAM emissions not only contribute to the global warming but also pose a significant hazard to mining safety due to the risk of accidental fires and explosions. This research presents a novel approach that investigates the capture of CH4 in a controlled environment using 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide [BMIM][TF2N] ionic liquid (IL), which is an environmentally friendly solvent. The experimental and modelling results confirm that CH4 absorption in [BMIM][TF2N], in a packed column, can be a promising technique for capturing CH4 from point sources, particularly the outlet streams of ventilation shafts in underground coal mines, which typically accounts for <1% v/v of the flow. This study assessed the effectiveness of CH4 removal in a packed bed column by testing various factors such as absorption temperature, liquid and gas flow rates, flow pattern, packing size, desorption temperature, and desorption pressure. According to the optimisation results, the following parameters can be used to achieve a CH4 removal efficiency of 23.8%: a gas flow rate of 0.1 L/min, a liquid flow rate of 0.5 L/min, a packing diameter of 6 mm, and absorption and desorption temperatures of 303 K and 403.15 K, respectively. Additionally, the experimental results indicated that ILs could concentrate CH4 in the simulated VAM stream by approximately 4 fold. It is important to note that the efficiency of CH4 removal was determined to be 3.5-fold higher compared to that of N2. Consequently, even though the VAM stream primarily contains N2, the IL used in the same stream shows a notably superior capacity for removing CH4 compared to N2. Furthermore, CH4 absorption with [BMIM][TF2N] is based on physical interactions, leading to reduced energy requirements for regeneration. These findings validate the method's effectiveness in mitigating CH4 emissions within the mining sector and enabling the concentration of VAM through a secure and energy-efficient procedure. [ABSTRACT FROM AUTHOR]

The rapid development and widespread use of ZnO nanoparticles (nZnO) in various industries have raised concerns about their potential environmental impact. Therefore, understanding the fate and role of nZnO in the natural environment is crucial for mitigating their hazardous effects on the environment and human safety. The purpose of the present study was to provide scientific support for understanding and eliminating the joint risk of nanoparticle and heavy metal pollution in the soil environment by revealing the co-transport characteristics of Cd(II) and ZnO nanoparticles (nZnO) in soil under different ionic strength (IS) and pH. The impacts of different IS and pH on the co-transport of Cd(II) and nZnO in a 20 cm long with an inner diameter of 2.5 cm acrylic column packed with 10 cm high soil samples were investigated in the present study. In the above system, a 500 μg L−1 Cd(II) loaded nZnO suspension pulse with varying IS or pH was introduced into the soil column for leaching over 5 PVs, followed up by 5 PVs background solutions without nZnO. The IS was 1, 10, or 50 mM NaCl, with pH6, or the pH was 6, 7 or 8 with 1 mM NaCl. Meanwhile, Sedimentation experiments for nZnO, adsorption of Cd(II) on soil, and nZnO, DLVO theory calculation for the same background condition were conducted. The presence of nZnO significantly increased the mobility of Cd(II) as a result of its strong adsorption capacity for nZnO-associated Cd(II). However, with the increase of IS, the co-transport of nZnO and Cd(II) was decreased and the retention of nZnO in the soil column due to more nZnO attended to aggregate and sediment during the transport and the decrease in the adsorption capacity of nZnO for Cd(II) by competition of Na+. When pH was 6, 7, and 8, the co-transport of nZnO and Cd(II) increased with higher pH due to the lower electrostatic attraction between nZnO and soil under higher pH. Meanwhile, the DLVO theory was fitted to describe the above co-transport process of nZnO and Cd(II). More attention should be paid to the presence of nZnO on the migration of Cd(II) in the natural soil to control the potential risk of nanoparticles and heavy metals to the environment. The risk of co-transport of nZnO and Cd(II) might be controlled by adjusting IS and pH in the soil solution. [ABSTRACT FROM AUTHOR]

Reducing the environmental issues brought on by nutrients especially nitrogen pollution and loss is important. Owing to its unique composition and physico-chemical characteristics, biomass-derived biochar exhibits varying degrees of adsorption and interception for all types of soil nutrients. Thus, a novel way to improve nutrient absorption in the soil is to include biomass derived biochar into it. Various biomass-derived biochar from locally available biobased substances was synthesized through low-cost portable charring kiln. It has been quantified the influence of four biobased substances and three pyrolysis temperature on different morphomineralogical characteristics of biochar for utilizing as low-cost sorbent to manage nutrient adsorption and retention capacity. The morphomineralogical characteristics were principally manipulated by feedstocks rather than pyrolysis temperature. Higher porosity and surface area of biomass-derived biochar illustrated its soil structural modification and nutrient retention capacity along with their utilization for adsorbents. With increase in pyrolysis temperature, the adsorption capacity of biochar for NH4+-N and NO3−-N was gradually weakened and gradually enhanced respectively. The adsorption process of ammonia nitrogen and nitrate nitrogen conformed to the Langmuir model and the fitted KL value was less than 1 indicating that the adsorption process was uniform monolayer adsorption and the adsorption of biochar was favorable adsorption. With increase in biochar application rate the leaching of NO3−-N decreased having higher at 2.5 t ha−1 application rate followed by 5 t ha−1 and lower at 7.5 t ha−1. In packed soil column, the NH4+-N in leachate was maximum in T7 (18.6), followed by T4 (17.9), T13 (17.3) and minimum in T10 (17.2) at same application rate of manures and biochar. Finally, results also revealed that packed soil column performed better as compared with intact soil column to retain soil nutrient and hence, leaching potential of nutrient was less in packed column than intact soil column. In conclusion, biomass-derived biochar can enhance the amount of nutrient that is absorbed into the soil while decreasing the loss of nutrient from the soil in the form of ammonia and nitrate. To sum up, biomass-derived biochar can increase the adsorption amount of the nitrogen and reduce the loss of ammonia nitrogen and nitrate nitrogen in the soil, thus retaining the nitrogen. [ABSTRACT FROM AUTHOR]

This document provides information on innovations in pilot-plant distillation process design, with a focus on small-scale distillation processes. It covers topics such as column internals, flexible distillation column concept, column-sizing software, decanters, and free-radical polymer formation. The document emphasizes the importance of equipment versatility and ease of assembly for laboratory and pilot-scale projects. It also discusses the use of glass trays and random packing as alternatives to trays, as well as structured packing for distillation effectiveness. The document provides information on various aspects of distillation columns and equipment used in laboratory and small-scale distillation processes, including the design and features of flexible distillation columns, the use of decanters for separating liquid phases, and the design of condensers for distillation columns involving polymerizable chemicals. It also addresses the challenges posed by polymerizable chemicals and provides examples of polymerization inhibitors. [Extracted from the article]

NOxare harmful pollutants emitted by many industries and must be removed before the gases are released into the atmosphere. Among the various techniques used for NOxremoval, reactive absorption by hydrogen peroxide in a packed column has the advantage of being able to transform NOxinto nitric acid which can be recycled and reused in the plants. This work aimed at modeling the NOx absorption by means of aqueous solutions of hydrogen peroxide and nitric acid, applied in a packed column operating under different representative conditions. The model established using the Aspen software considers the equilibrium and the kinetics of the reactions taking place both in the gas phase and in the liquid phase as well as the thermodynamic properties of the chemical (molecular and ionic) components estimated using the Electrolyte NRTL model. It allows predicting NOxabsorption performances in terms of efficiency and selectivity. The model was validated by comparing simulation results with experimental ones obtained in a pilot-scale absorption column and published previously. The predicted values are in satisfactory agreement with the experimental data showing a deviation between 5 and 8%. Therefore, the model developed in this work could be advantageously used to design industrial-scale reactive NOxabsorption columns. [ABSTRACT FROM AUTHOR]

Carbitol acetate (CA) could be a remarkable for CO2 absorption due to its high boiling point, low viscosity, and high CO2 solubility. Using a laboratory-scale Raschig ring packed-column, mass transfer studies of CO2 in carbitol acetate have been performed at ambient temperature and pressure. Liquid and gas side physical individual mass transfer coefficients (kL0a, kc0a) were determined by oxygen desorption method and by sulfur dioxide absorption into sodium hydroxide solution (NaOH), respectively. Also, gas side overall chemical and physical mass transfer coefficients (Kca, Kc0a) were experimentally determined by the CO2 absorption into NaOH solution and CA. Results show that Kca and Kc0a increase with increasing gas and liquid velocities. The results also showed that (Kc0a)CA and (Kca)NaOH were 2.2 and 2.5 times greater than that of water, respectively. It is known that the chemical absorption mechanism is more effective than the physical absorption mechanism. According to the (Kc0a)water comparison, (Kc0a)CA and (Kca)NaOH have almost shown close results. Carbitol acetate has been shown to be a potential absorbent for CO2 absorption process and could be a viable alternative with further research and development. Also, nonlinear regression analyses were performed, and correlations were developed for mass transfer coefficients. [ABSTRACT FROM AUTHOR]

Background Zinc helps with cell division, growth, wound healing, and carbohydrate breakdown. Humanbeings have to obtain zinc from food or supplements because our bodies do not produce it naturally. In view of the greater advantages (such as low cost, time of analysis, and stability-indicating) compared to other quantification methods (titration, ion chromatography, Atomic absorption spectroscopy) proposed in the literature, a refractive index detector coupled with HPLC has been used in quantification of zinc. Objective The goal of this research is to develop and validate a sensitive, low-cost, high-resolution, and stability- indicating method for detecting and quantifying zinc levels in zinc supplement pharmaceutical products (injectables, tablets, and capsules). Methods A novel isocratic reverse-phase HPLC method with a refractive index detector (with sensitivity 64, detector temperature 35°C, and positive polarity) was developed using a carboxyl functional group packed column and 0.8% (v/v) formic acid as the mobile phase to detect and quantify zinc content. Results The reported method has a good optimal sensitivity (LOQ: 0.006 mg/mL and LOD: 0.002 mg/mL). The correlation coefficient (r) obtained from the zinc calibration plot was greater than 0.998, indicating that the method was linear and that there was a strong correlation between zinc concentration (0.006 mg/mL to 0.375 mg/mL) and peak response. The accuracy at LOQ level was found to be 95–105% and 97–103% at the remaining levels (50, 100, and 150%). Conclusion The proposed method was successfully developed and validated as per International council for harmonisation (ICH) guidelines. Therefore, this method can be used for the quantitative testing of zinc in the QC laboratory. Highlights A novel method was developed for zinc levels determination in pharmaceutical products using HPLC with a refractive index detector. The present approach has a quick run time of 10 min and is inexpensive. [ABSTRACT FROM AUTHOR]

This study aimed to assess the dynamic simulation models provided by Aspen adsorption (ASPAD) and artificial neural network (ANN) in understanding the adsorption behavior of atenolol (ATN) on gasified Glyricidia sepium woodchips activated carbon (GGSWAC) within fixed bed columns for wastewater treatment. The findings demonstrated that increasing the bed height from 1 to 3 cm extended breakthrough and exhaustion times while enhancing adsorption capacity. Conversely, higher initial ATN concentrations resulted in shorter breakthrough and exhaustion times but increased adsorption capacity. Elevated influent flow rates reduced breakthrough and exhaustion times while maintaining constant adsorption capacity. The ASPAD software demonstrated competence in accurately modeling the crucial exhaustion points. However, there is room for enhancement in forecasting breakthrough times, as it exhibited deviations ranging from 6.52 to 239.53% when compared to the actual experimental data. ANN models in both MATLAB and Python demonstrated precise predictive abilities, with the Python model (R2 = 0.985) outperforming the MATLAB model (R2 = 0.9691). The Python ANN also exhibited superior fitting performance with lower MSE and MAE. The most influential factor was the initial ATN concentration (28.96%), followed by bed height (26.39%), influent flow rate (22.43%), and total effluent time (22.22%). The findings of this study offer an extensive comprehension of breakthrough patterns and enable accurate forecasts of column performance. [ABSTRACT FROM AUTHOR]

In this work, we discuss the development of a compact analytical instrument for monitoring ethylene in compact greenhouses utilized by NASA to grow fresh vegetables in space. Traditionally, ethylene measurements are conducted by GC-MS systems. However, in space, they are not applicable due to their bulky size, heavy weight, special carrier gas requirement and high maintenance. Our group developed a compact and robust battery-powered ethylene monitor based on the principles of analytical gas chromatography. The device utilizes purified ambient air as a carrier gas and a metal oxide sensor as a GC detector. Implementation of a CarboWax 20 M packed column from Restek together with a Tenax TA pre-concentrator allowed us to achieve a 20 ppb limit of detection for ethylene. Full automation of measurements and reporting of concentrations was accomplished via the implementation of a Raspberry Pi 4 computer and a 7″ 720P LED capacitive touchscreen utilized for data output. Based on a feasibility study, a fully automated, industrial-grade ethylene monitoring and removal system for greenhouses was developed. [ABSTRACT FROM AUTHOR]

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The default choice of mobile phase acidifier for bottom-up LC-MS proteomic analyses is 0.10% formic acid because of its decent acidity, decent ion pairing ability, and low suppression of electrospray ionization. In recent years, state-of-the-art columns have been designed specifically to provide efficient separation even when using an MS-friendly mobile phase of low ionic strength. Despite this, no attempts have been made to improve the sensitivity of the MS-based analytical methods by reducing the amount of formic acid in the mobile phase. In this study, we evaluated the effect of reduced formic acid concentration in the mobile phase on the chromatographic behavior and MS response of peptides when separated using columns packed with a C18 stationary phase with a positively charged surface. Using 0.01% formic acid in the mobile phase maintained excellent chromatographic performance and increased MS signal response compared to the standard of 0.10%. The enhanced MS response translated to about 50% improved peptide identifications depending on the complexity and amount of sample injected. The increased retention of peptides at a reduced formic acid concentration was directly proportional to the number of acidic residues in the peptide sequence. The study was carried out by covering a spectrum of protein samples with varied complexity using analytical flow, micro-, and nanoflow regimes to expand the applicability in routine practice. [ABSTRACT FROM AUTHOR]

Triclosan (TCS) has been regarded as an emerging contaminant in aquatic systems, making its efficient removal of great significance. In this study, NPVMo@iPAF-1, with a specific surface area of 665 m2/g, was prepared by incorporating (NH4)5H6PV8Mo4O40 into porous aromatic frameworks (PAF). The maximum adsorption capacity of TCS on NPVMo@iPAF-1 reached 917.1 mg/g, as calculated from the Langmuir model. Fixed-bed columns packed with NPVMo@iPAF-1 were employed for TCS removal; the experiment data strongly correlated with the Thomas and Yoon-Nelson models under different operational conditions. Pore preservation, electrostatic effects, and the synergistic effect of π-π interactions contributed to the effective adsorption of TCS onto NPVMo@iPAF-1. The NPVMo@iPAF-1 fixed-bed column could be effectively regenerated through in-situ ozonation for more than 10 regeneration cycles. NPVMo@iPAF-1 turned out to be a promising adsorbent for removing TCS not only from pure water but also from reclaimed water and surface water samples. [ABSTRACT FROM AUTHOR]

Succinic acid (SA) is one of the most demanded and widely used constituents for producing various healthcare and skincare products, biodegradable polymers, and food and feed additives. The present study was undertaken to establish the protocol for selective recovery of SA from a complex matrix of Japanese quince (JQ) (Chaenomeles japonica) fruit using ion-exchange fractionation resin DIAION™ UBK550 with negatively charged functional groups cross-linked with a styrene-divinylbenzene matrix. A second SA purification method was used for data comparison using either Supel™-Select HLB or Strata-X columns packed with a hydrophilic modified sty-rene-based polymer. The analysis of SA accomplished by multiple reaction monitoring (MRM) using triple quadrupole mass selective detection (HPLC-ESI-TQ-MS/MS) revealed the presence of SA in the JQ juice without pretreatment, in the amount of 0.202 mg·100 ml–1. The use of sty-rene-based polymer Strata-X sorbent for purification of JQ juice led to an increase of 11.0% in the concentration of SA compared with the initial concentration of SA in JQ juice. On the other hand, after purification of JQ juice with Supel™-Select HLB, the concentration of desorbed SA in the eluate fraction was 7.8% lower compared to the initial concentration. The use of ion-exchange fractionation resin DIAION™ UBK550 for purification and concentration of JQ juice ensured up to 152.3 mg of SA in 100 ml–1 of syrup-like brown substance, which was much (754.4-fold) higher than that observed in JQ juice itself. All three sorbents ensured the complete removal of monoand disaccharides from the juice, as no signs of mono- and disaccharides were detected in the eluate fractions. [ABSTRACT FROM AUTHOR]

A model system is established using Aspen Plus process simulation software for a 166 752 m³/h (dry basis) raw gas decarbonization process using methyldiethanolamine(MDEA) and piperazine(PZ) as composite absorption solvents. The simulation results indicate that the theoretical number of plates, packing height and tower diameter in the MDEA-PZ solvent decarbonization process should be optimized while ensuring absorption and regeneration effects and avoiding tower flooding. The height of the absorption tower packing has a large design margin, and when the number of effective plates exceeds 16, which can meet the mass transfer requirements. As the number of trays in the lower section of the regeneration tower increases, the amount of carbon dioxide regeneration also increases, indicating that the longer the contact gas extraction time, the more conducive it is to the regeneration of carbon dioxide. When the number of plates in the lower section of the regeneration tower is 25, which can meet the requirements. If the number of plates in the upper section of the regeneration tower is greater than 15, which can meet the requirements. [ABSTRACT FROM AUTHOR]

The use of an ozonized bubble column reactor (OBCR) in wastewater treatment is advantageous due to its efficient mixing and mass transfer characteristics. Among all high-performance features, the ozonation reaction in a BCR undergoes a low dissolution of O3 in the reactor with a limited reaction rate. In this study, the ozonation reaction of phenol in an OBCR was tested using a ZnO nanocatalyst and alumina balls as packing material. Three concentrations of O3 were evaluated (i.e., 10, 15, and 20 ppm), and 20 ppm was found to be the optimum concentration for phenol degradation. Also, two doses (i.e., 0.05 and 0.1 g/L) of ZnO nanocatalysts were applied in the reaction mixture, with the optimal dose found to be 0.1 g/L. Accordingly, three phenol concentrations were investigated in the OBCR (i.e., 15, 20, and 25 ppm) using four treatment methods (i.e., O3 alone, O3/Al2O3, O3/ZnO nanocatalyst, and O3/Al2O3/ZnO nanocatalyst). At a contact time of 60 min and phenol concentration of 15 ppm, the removal rate was 66.2, 73.1, 74.5, and 86.8% for each treatment method, respectively. The treatment experiment that applied the O3/Al2O3/ZnO nanocatalyst produced the highest phenol conversion into CO2 and H2O in the shortest contact time for all phenol concentrations. Thus, the OBCR employed with a ZnO nanocatalyst plus packing material is a promising technology for the rapid and active removal of phenol because it enhances the number of hydroxyl radicals (•OH) generated, which ultimately increases the oxidation activity in the OBCR. Also, the results showed efficient flow characteristics in the OBCR, with channeling problems averted due to appropriate gas movement resulting from the use of packing materials. Finally, it was found that the ozonation process in an OBCR is an efficient method for phenol conversion with good economic feasibility. [ABSTRACT FROM AUTHOR]

We investigated the interfaces of the epiphyseal plate with over‐ and underlying bone segments using an integrated approach of histochemistry, microtomography and scanning electron microscopy (SEM) to overcome the inherent limitations of sections‐based techniques. Microtomography was able to provide an unobstructed, frontal view of large expanses of the two bone surfaces facing the growth plate, while SEM observation after removal of the soft matrix granted an equally unhindered access with a higher resolution. The two interfaces appeared widely dissimilar. On the diaphyseal side the hypertrophic chondrocytes were arranged in tall columns packed in a sort of compact palisade; the interposed extracellular matrix was actively calcifying into a thick mineralized crust growing towards the epiphysis. Behind the mineralization front, histochemical data revealed a number of surviving cartilage islets which were being slowly remodelled into bone. In contrast, the epiphyseal side of the cartilage consisted of a relatively quiescent reserve zone whose mineralization was marginal in amount and discontinuous in extension; the epiphyseal bone consisted of a loose trabecular meshwork, with ample vascular spaces opening directly into the non‐mineralized cartilage. On both sides the calcification process took place through the formation of spheroidal bodies 1–2 μm wide which gradually grew by apposition and coalesced into a solid mass, in a way distinctly different from that of bone and other calcified tissues. [ABSTRACT FROM AUTHOR]

In this study, for the first time, we investigate cobalt-mediated radical block copolymerization of vinyl acetate (VAc) and methyl acrylate (MA) in a packed column system in the presence of cobalt(II) acetylacetonate (Co (acac)2) as a controlling agent. This copolymerization system has the capability to remove the residual catalyst and separate copolymers with different molecular weights, simultaneous to polymerization. Synthesis of high-purity poly (vinyl acetate)-b-poly(methyl acrylate-co-vinyl acctate) (PVAc-b-P(MA-co-VAc)) copolymers were successfully performed by initiating the radical copolymerization of MA and VAc from PVAc-Co (acac)2 macroinitiator in the packed column with silica gel particles. Copolymerization reaction proceeds via a controlled characteristic with first-order kinetics with respect to monomers, predetermined molecular weight, and relatively narrow molecular weight distribution. GPC, 1HNMR, and DSC analyses demonstrated that the PVAc-b-P(MA-co-VAc) was formed with a blocky structure. Based on the analyses, it was found that the VAc content in the block copolymer progressively increased with increasing conversion in the constant VAc initial ratio, indicating that the second block copolymer had a gradient sequence distribution. Moreover, the VAc and MA reactivity ratios in the packed column with silica gel particles were calculated using the extended Kelen–Tudos method to be rMA = 4.98 and rVAc = 0.62, respectively. [ABSTRACT FROM AUTHOR]

A novel simple sensitive and effective on-line flow injection column preconcentration platform using poly-tetrafluoroethylene turnings as sorbent was developed prior to flame atomic absorption spectrometric (FAAS) determination of palladium in vehicle exhaust catalysts, hydrogenation catalysts and environmental water samples. The method is based on the sorption of palladium(II)-diethyldithiophosphate, which was found to be more effective than dithiocarbamate ones. Methyl isobutyl ketone (MIBK) was used as eluent prior atomisation and quantification. All parameters like pH, DDPA concentration, flow rates, preconcentration time that affect the sensitivity of the method as well as interferences of other metals were investigated in detail. The enhancement factor calculated as 114 for 60 s preconcentration time while the sampling frequency as 40 h−1. The detection limit was 0.9 μg L−1 and the relative standard deviation (RSD) was 2.8% at 20.0 μg L−1 concentration level. The accuracy of the proposed method was estimated by analysing certified reference material and spiked environmental samples. The analytical features of the method were compared with other on-line column preconcentration methods reported in the literature. [ABSTRACT FROM AUTHOR]

This research describes a hybrid solar desalination system that includes a humidification-dehumidification unit as well as a solar still unit. The current system is being studied numerically. A one-dimensional model of the important heat and mass exchanges, as well as the flow field, was built using the finite difference method. Freshwater productivity is calculated under various operating and weather conditions. The model has been modified to investigate the steady-state behavior of the system components. Four major parameters that have a significant impact on system water production are investigated: the feed flow rate of cooling water through the dehumidifier unit, the airflow rate, and the number and height of packing columns. According to the results, the proposed hybrid desalination system provides appropriate operational compatibility between HDH technology and solar energy. The system can provide a daily production of up to 35 liters per day. Increasing the number of packing columns results in a higher increase in fresh water productivity than increasing the height of the packing columns. The optimal air flow rate at a constant saline-water flow rate is obtained. For high airflow rates, the packing column height doesn't significantly affect the daily water production. System performance is investigated by four main parameters: gained output ratio (GOR), humidifier efficiency, exergy efficiency, and system efficiency. The system efficiency reached about 65% and the GOR reached 3.1. The humidifier's efficiency varied between 50% and 75%. The maximum exergy efficiency reached about 5.2%. [ABSTRACT FROM AUTHOR]

The recovery of enriched Zn-68 is extremely important in the production of short-lived isotope (Ga-67) in the Cyclotron because of its high price. A high amount of Zn-68 is produced during the production of Ga-67 from its target (Zn-target) by a solvent extraction technique. In this investigation, we successfully prepared poly(vinyl alcohol-t-acrylamide), P(VA-t-AM) resin using the gamma radiolysis technique. The characterization of pristine PVA and synthesized P(VA-t-AM) was performed to confirm their structures. The produced polymer was tested for the elimination of Zn2+ ions from simulated liquid waste as produced during the production of the Ga-67. To get the highest uptake of Zn2+ ions on the polymer, various parameters such as solution pH, polymer weight, and contact time were applied. The loading Zn2+ ions were studied at optimum conditions of the Batch approach. Then, the retrieval of Zn2+ ions from the packed chromatographic column was tested using different parameters such as flow rates, bed depths, and initial concentration of Zn2+. The results indicated that the percentages of loaded Zn2+ ions on the packed column were 96.94% at the best operational conditions. Moreover, different eluents were applied to the retrieval of Zn2+ ions from the P(VA-t-AM) column, and the data confirmed that the retrieval percentage of Zn2+ ions from P(VA-t-AM) was 98.43% at the optimum. The reusability of the working polymer was examined for eight cycles. This paper recommended that the synthesized P(VA-t-AM) can be utilized for the retrieval of Zn2+ ions from the spent Zn-68 target in the Cyclotron. [ABSTRACT FROM AUTHOR]