Increasing Adsorption Temperature Research Articles

A study on the performance of a recyclable adsorbent La@Fe for phosphate adsorption in wastewater

Phosphorus(P) is the key element of the growth of phytoplankton, and is also significant cause of water eutrophication. In this work, the magnetic Fe3O4 (FE) microspheres were employed as the core material, the La compound was coated on the surface of the FE microspheres and the adsorbent obtained was denoted as La@Fe. The effects of preparation conditions including the dosage of NaOH, the preparation time, the ratio of FE and LaCl3 (LC), and the stirring time were discussed. The optimized La@Fe has a good adsorption capacity (130–160 mg·g−1) and strong magnetic recovery capacity (43.4 emu/g). In the low concentration (1 mg·L−1), the optimized La@Fe still had an excellent performance. It can keep a good adsorption in a wide pH range (3−8). Except Na2CO3, common anions (NaHCO3, NaCl, NaNO3, Na2SO4, KF, KNO2) in the wastewater could not affect the adsorption capacity of La@Fe. After 7 regeneration, the adsorption capacity of La@Fe reduced by 25% indicating the excellent regeneration property of La@Fe. The La@Fe was analyzed by SEM, TEM, XRD, XPS, BET, and LPS, and the obtained results showed that the particles of La@Fe were spherical, the particle sizes were between 0.1 and 100μm. The main components at the surface of La@Fe was La-(OH), which adsorbed phosphate to form La-PO4. The specific surface area of La@Fe was small and the mesopores were main pore structure. In addition, the adsorption kinetics analysis indicated that the Elovich model worked well on modeling La@Fe adsorbing phosphate, so the adsorption was chemical adsorption with heterogeneous adsorbing surfaces. Adsorption isotherms experiments revealed that the increasing adsorption temperature would enhance the adsorption capacity of La@Fe. It could be obtained from the thermodynamic experiments that the adsorption process was endothermic and chemical adsorption. Therefore, La@Fe is an excellent phosphate adsorbent and has a good application prospect in the field of phosphorus recovery and adsorbent reuse.

Diclofenac sodium adsorption in aqueous media by activated carbon obtained from einkorn (Triticum monococcum L.) husk

AbstractThe uncontrolled release of waste diclofenac with low biodegradability is considered to be a potential threat for the environment and creatures. To find effective solution for this issue, this study reports the adsorption performance of diclofenac sodium salt (DCF) by using activated carbon (EHAC) obtained from einkorn (Triticum monococcum L.) husk in aqueous solution under various circumstances. It was found that DCF adsorption on EHAC was highly solution pH dependent, and DCF adsorption by EHAC decreased with increasing adsorption temperature. Equilibrium data showed that fitted isotherm model with the experiment results of DCF adsorption on EHAC followed the order of Langmuir > Temkin > Freundlich > Dubinin-Radushkevich. Adsorption capacity of EHAC for DCF adsorption in aqueous solution was calculated to be 147.06 mg/g at 25 °C. The adsorption kinetic of DCF adsorption on EHAC was determined to obey the pseudo-second-order kinetic model. By utilizing FTIR and pH data obtained from DCF adsorption on EHAC, DCF adsorption mechanisms with some interactions such as π-π stacking, electrostatic interactions, and hydrogen bonding were suggested at diverse pH values. Additionally, intraparticle diffusion model was applied to kinetic results to further recognize the kinetic mechanism of DCF adsorption on EHAC. Furthermore, thermodynamic parameters for DCF adsorption on EHAC were calculated and evaluated, in which DCF adsorption process by EHAC was determined to be exothermic, spontaneous, and feasible.

Magnetic and PEG-crosslinked poly(methyl acrylate) functionalized with triethylenetetramine for removal of lead ions from contaminated water

A new magnetic polymer adsorbent with high swellability was prepared based on a PEG-crosslinked poly(methyl acrylate) via ATRP technique. FT-IR, TGA, CHN, FE-SEM, EDX, XRD, VSM, BET, and DLS measurements were used for the characterization of the prepared adsorbent. After replacing terminal bromines with triethylenetetramine chelating agent, the adsorption process of lead ions led to the removal of these ions from aqueous solutions. The removal of lead ions was investigated using ICP-OES technique. At pH = 7, the equilibrium adsorption capacity increased significantly and reached 37 mg/g at a contact time of 60 min. The adsorption capacity increased with increasing adsorption temperature (up to 40 °C) and initial concentration of lead ions (up to 70 mg/L), while it decreased with increasing adsorbent dose. The Freundlich isotherm better described the process of adsorption of lead ions by the prepared adsorbent. The adsorption kinetic was in greater agreement with pseudo-second-order model. The prepared adsorbent performed much better in adsorbing lead ions compared to cobalt and mercury ions. By performing the adsorption–desorption process three times, it was found that the adsorbent has high reusability. Overall, high swelling behavior and ease of magnetizability are two prominent features of the newly prepared adsorbent.

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.

A Study on the Influence and Mechanism of Temperature and Dosage on PCDD/Fs Adsorption via Coal-Based Activated Carbon

Using a trace polychlorinated-ρ-dibenzodioxins and dibenzofurans (PCDD/Fs) stabilizing generator, an experimental study related to the influence of temperature (150, 165, and 180 °C) and activated carbon (AC) dosage (0.10, 0.15, and 0.20 g) on the adsorption effect of gas-phase PCDD/Fs via coal-based AC was conducted. Increasing the AC dosage is the most efficient method to improve the PCDD/Fs adsorption efficiency from 65.8% (0.10 g) to 93.0% (0.20 g) at 150 °C in an exponential trend. Both the polychlorinated-ρ-dibenzodioxins (PCDD)/polychlorinated dibenzofurans (PCDF) ratio and the Cl-PCDD/Fs value showed positive correlations, with the AC dosage under the same temperature. Increasing adsorption temperature declined the adsorption capacity of AC, resulting in the exponentially decreased average I-TEQ value adsorbed per gram of AC, from 131.3 ng TEQ/Nm3 (150 °C) to 55.9 ng TEQ/Nm3 (180 °C). The coal-based AC used in this study preferred to adsorb lower chlorinated PCDD/Fs, tetrachlorianted dibenzo-p-dioxin and dibenzofurans (TCDD/Fs), and pentachlorianted dibenzo-p-dioxin and dibenzofurans (PeCDD/Fs) than highly chlorinated PCDD/Fs, heptachlorianted dibenzo-p-dioxin and dibenzofurans (HpCDD/Fs), hexachlorinated dibenzo-p-dioxin and dibenzofurans (HxCDD/Fs), and octachlorianted dibenzo-p-dioxin and dibenzofurans (OCDD/Fs), which was aggravated by the increasing temperature. The characterization of the surface properties of AC revealed that slight oxidation occurred on the AC surface during the adsorption process, introducing oxygen to the competitive adsorption. In addition, it was found in this study that an increased temperature led to a higher content of hydrophilic carboxyl and anhydride groups and weakened π-π interactions, which were also partly responsible for the negative impact of the increasing temperature on the AC adsorption capacity. The results of this study can contribute to the operation optimization for controlling PCDD/F emissions from municipal solid waste incineration (MSWI).

Effect of hydrothermal pH values on the morphology of special microspheres of lignin-based porous carbon and the mechanism of carbon dioxide adsorption

The study reports the economic and sustainable syntheses of a lignin-based porous carbon (LPC) for CO2 capture application. The pH values of hydrothermal solution affected the polymerization and aromatization of spheroidization, with morphological changes from blocky to microsphere. In addition, the reliable mechanisms of CO2 adsorption were proposed by combining experiments with Gaussian16 simulations based on DFT. The electrostatic attraction of oxygen-containing functional groups and the diffusivity resistance of CO2 in the pores are the key factors for the CO2 adsorption. ​The carboxyl groups have the strongest electrostatic attraction to CO2. LPC-pH 1 has the highest carboxyl group content, possessing a CO2 adsorption capacity of up to 5.10 mmol/g at 0℃, 1 bar. Furthermore, CO2 diffusion resistance became a main factor as the adsorption temperature increases. The innovative combination of quantum chemical calculations and microscopic properties provides a viable pathway for an insight into the future control of lignin-based carbon formation.

Defective UiO-66 metal–organic gels for optimizing gaseous toluene capture

Developing high-performance sorbents for volatile organic compounds (VOCs) is urgently required for environmental cleaning and personnel protection. Zirconium-based metal–organic frameworks (Zr-MOFs) have been deemed attractive candidates for gaseous toluene capture due to their superior stability and high adsorption capacity. However, the practical application of powdered Zr-MOFs is hindered by inherent limitations. Here, we report a series of defective UiO-66 metal–organic gels (G66-X) with variable missing linker deficiency by altering the modulator concentration. The defect concentration of the adsorbents has a significant impact on the porosity and gaseous toluene adsorption capacity. Dynamic breakthrough results reveal that G66-9 demonstrates optimal breakthrough time of 336 min/g and uptake amount of 334 mg/g, outperforming those of many other typical toluene adsorbents. The breakthrough times and the uptake capacities dramatically decrease with the increase of adsorption temperature. An outstanding regeneration performance of adsorbents can almost maintain even after five adsorption–desorption cycles.

Thermodynamics Study of Adsorption of Oil Hydrocarbons from aqueous solutions onto the Porcelanite Surface

This work describes removal of hydrocarbons from aqueous solution using porcelanite as an adsorbent surface with investigation of some factors that affect on adsorption process of the hydrocarbons such as contact time, primary hydrocarbons concentration in the solution, adsorbent particle size and temperature of the solution. Removal of hydrocarbons was conducted using the batch method. From the obtained results, it was found that, the quantity of adsorbed hydrocarbons was increased with increase in adsorption temperature .Equilibrium time was attained at 30min for efficient removal of hydrocarbons. Removal percentage of hydrocarbons over porcelanite powder was found to be 41.61% and the amount of adsorbed hydrocarbons over porcelanite was 83.22(mg/g). The results of adsorption processes were more fitted with Friendlich model rather than Langmuir adsorption model. Thermodynamic study showed that, ΔH was endothermic, ΔG at the values were negative at lower concentrations and then turned positive when concentrations increased and ΔS was found to be positive.

Enhanced SO2 adsorption performance on nitrogen-doped biochar: Insights from generalized two-dimensional correlation infrared spectroscopy

Nitrogen-doped biochar is considered as a renewable, cost-effective, and promising SO2 adsorbent. However, it is difficult to improve the physicochemical properties of biochar synergistically and clarify the adsorption mechanism. Therefore, in this study, a one-step high-temperature CO2-NH3 modification method was proposed for biochar to improve its SO2 adsorption, and the in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (in situ DRIFTS) was used to reveal the interface reaction mechanism between SO2 and nitrogen-doped biochar. The results showed that when the modification temperature exceeded 700 °C, CO2 and NH3 exhibited significant thermal activation and nitrogen doping on biochar simultaneously. Under a modification temperature of 800 °C (BCAN-800), the microporous surface area and nitrogen content of modified biochar reached the highest value of 563.83 m2/g and 6.63 wt%. The SO2 adsorption capacities of BCAN-800 were up to 201.89 mg/g and 145.68 mg/g at 30 °C and 120 °C, respectively. The results of in situ DRIFTS showed that dimeric and bridge hydrogen bonds were the main SO2 adsorption sites on nitrogen-doped biochar at 30 °C. With the increase of adsorption temperature, nitrogen-containing groups as the main adsorption site could combine with SO2 to form sulfamide (60 °C), which eventually existed in a more stable form of SO42−/R-O-SO2-OR′ (120 °C).

Preparation of Activated Boron Nitride and Its Adsorption Characteristics for Zn, Cu, and Cd in Flue Gas.

Developing non-carbon-based adsorbents is essential for removing heavy metals from post-incineration flue gas. In this study, a new high-temperature-resistant adsorbent-activated boron nitride (BN) was prepared using precursors combined with a high-temperature activation method. The adsorption characteristics of BN for Zn, Cu, and Cd in simulated flue gas and sludge incineration flue gas were investigated using gas-phase heavy metal adsorption experiments. The results showed that BN prepared at 1350 °C for 4 h had defect structures, abundant pores, functional groups, and a high specific surface area of 658 m2/g. The adsorption capacity of BN in simulated flue gases decreases with increasing adsorption temperature, whereas it is always higher than that of activated carbon (AC). The total adsorption capacities for Zn, Cu, and Cd were the highest at 50 °C with 48.3 mg/g. BN had strong adsorption selectivity for Zn, with a maximum adsorption capacity of 54.45 mg/g, and its adsorption process occurred mainly on the surface. Cu and Cd inhibited Zn adsorption, leading to a decrease in the Zn adsorption capacity. In sludge incineration flue gas, BN can quickly reach adsorption equilibrium. The BN had a synergistic disposal capacity for heavy metals and fine particulate matter. The maximum adsorption capacity was reduced compared to the simulated flue gas adsorption capacity, which was 5.1 mg/g. However, BN still exhibited a strong adsorption selectivity for Zn, and its adsorption capacity was always greater than that of AC. The rich functional groups and high specific surface area enable BN to physically and chemically double-adsorb heavy metals.

Thermodynamic analysis of a novel trans-critical compressed carbon dioxide energy storage system based on 13X zeolite temperature swing adsorption

As a promising large-scale physical energy storage technology, the main challenge of compressed CO2 energy storage currently is the issue of low-pressure CO2 high-density storage. To address that issue, a novel trans-critical compressed CO2 energy storage system based on 13X zeolite variable temperature adsorption (TSA-TC-CCES) is proposed in this paper. Based on the principle of 13X zeolite adsorption gas storage, combined with the temperature swing adsorption (TSA) method and contact heat exchange scheme, it realizes low-pressure CO2 high-density storage and real-time internal circulation of heat. Under the design conditions, the adsorption tower volume, system round-trip efficiency, energy storage density, energy efficiency, and energy cycle efficiency are 360.55 m3, 89.19%, 6.29 kW ⋅ h/m3, 70.8%, and 93.53%, respectively. The sensitivity analysis results indicate that energy storage density and round-trip efficiency decrease with increasing adsorption temperature while growing with increasing desorption temperature. The increase in storage pressure positively affects energy storage density, while the increasing storage temperature harms energy storage density. The release pressure at the critical point causes abrupt changes in system performance.

Co-capture of PbCl2 and CdCl2 vapors in a high-temperature furnace by green-produced calcium carbonate/montmorillonite composite sorbent

Injecting sorbent into the furnace is a promising technology for heavy metal emission control, and the development of high-performance in-furnace sorbents is of great importance. In this work, the thermal interaction behavior of calcium carbonate/montmorillonite (CM) composite sorbents at high temperatures and the adsorption of heavy metal chloride vapors were investigated. The adsorption performance of the green-produced calcium carbonate/montmorillonite composite sorbent for PbCl2 and CdCl2 vapors was investigated in a self-designed gas-solid two-phase rapid adsorption experimental system. The composite sorbent exhibited better adsorption performance for heavy metal chloride vapors than the single mineral sorbent. When the doping mass ratio of calcium carbonate was 30%, it exhibited superior heavy metal chloride vapor adsorption capacity at 700 ℃ and 800 ℃. The increase of adsorption temperature was beneficial to improved stability of heavy metal elements in the adsorption products. The addition of O2 promoted the adsorption of Pb and Cd by the sorbent, while the presence of CO2, SO2 and NO inhibited the adsorption of Pb and Cd. The characterization results indicated that the calcia-silica-alumina component of the CM composite sorbent underwent a series of thermal interactions at high temperatures. The presence of calcium changed the mineral evolution of the silica-alumina component, produced more active components, and promoted the high-temperature melting of the sorbent. In addition, the excellent pore properties of the CM composite at high temperatures facilitated the rapid diffusion of heavy metal chloride vapor, which also promoted the adsorption of heavy metals.

An efficient biochar adsorbent for CO2 capture: Combined experimental and theoretical study on the promotion mechanism of N-doping

The N-doped carbon material is one of the most efficient adsorption materials in the field of carbon capture. Although many N-doped carbon materials have been prepared for CO2 adsorption in recent years, the promotion mechanism of N-doping has not been clearly proposed. In this study, a series of N-doped biochars were successfully prepared by a facile solvent-free method. Among them, the biochar prepared with corncob powder, K2CO3 and urea at 800 °C showed the highest adsorption capacity (5.69 mmol/g at 0 °C and 1 bar) and selectivity (38.24 at CO2/N2 = 10/90). The biochar also exhibited excellent thermal stability and cycle performance. Notable, correlation analysis showed that ultra-micropores were the decisive factor for CO2 adsorption at low temperatures; nevertheless, the effect of N-doping would gradually appear with the increase of adsorption temperature. By fitting the kinetics of CO2 adsorption, it was found experimentally that N-doping could increase the activation energy between biochar and CO2. Next, through constructing biochar models with different nitrogen contents and different N-doping forms, it was found from theoretical calculation that N-doping could increase the adsorption energy between CO2 and biochar. Further theoretical analysis found that N-doping mainly enhanced the dispersion interaction between the biochar surface and CO2 to improve the adsorption performance, and the higher the nitrogen content, the more obvious the improvement. This work not only prepared a N-doped biochar with excellent CO2 adsorption performance from waste biomass, but also revealed the promotion mechanism of N-doping in detail by combining theoretical calculations with experiments.

Potential of waste mangosteen shell in the removal of cadmium ions: Effects of pH, contact time, and temperature

In this study, waste biomass adsorbents produced from mangosteen shells (MGS) were prepared (denoted as MGS500 and MGS1000). The physical and chemical characteristics, such as scanning electron microscopy, thermogravimetric-differential thermal analysis, specific surface area, pore volumes, surface functional groups, and point of zero charge of the prepared MGS samples were determined, and the adsorption capacity of cadmium ions from aqueous media was assessed. The effects of pH, adsorption time, temperature, and coexistence on adsorption were carefully assessed using an inductively coupled plasma optical emission spectrometer under several experimental conditions. The adsorption capacity decreased in the order, MGS < MGS500 < MGS1000. The optimal pH for cadmium ion removal was 5.0. The amount of cadmium ions adsorbed gradually increased with time, and adsorption equilibrium was achieved within 24 h after adsorption. Additionally, the amount of adsorbed cadmium ions increased with increasing adsorption temperature. To elucidate the adsorption mechanism in detail, the elemental distribution and X-ray photoelectron spectra of the prepared adsorbents were analyzed. Finally, desorption solutions such as HNO3, H2O, and NaOH were used to desorb the absorbed cadmium ions from MGS1000. Under our experimental conditions, the desorption percentage of cadmium ions was approximately 98.8% using HNO3. In conclusion, MGS1000 exhibited a good adsorption capacity of 12.0 mg/g for adsorbing cadmium ions from aqueous media and desorption capacity with HNO3 at 1000 mmol/L.

A study on and adsorption mechanism of ammonium nitrogen by modified corn straw biochar.

Using corn stover as raw material, the adsorption mechanism of ammonium nitrogen by biochar prepared by different modification methods was studied. The biochar was characterized by Fourier transform infrared spectroscopy, surface-area analysis and scanning electron microscopy. The results showed that the adsorption of by different modified biochars confirmed the quasi-second-order kinetic equation (R 2 > 0.95, p ≤ 0.05), the adsorption isotherms of the Langmuir equation (R 2 ≥ 0.96, p ≤ 0.05). ΔG θ < 0, ΔH θ > 0 indicated that the adsorption of by different modified biochars was a spontaneous endothermic reaction. With the increase in adsorption temperature, the adsorption capacity of biochar to ammonium nitrogen increased gradually. The adsorption was monolayer adsorption and was controlled by a fast reaction. Both KOH and FeCl3 modified biochars significantly improved the adsorption capacity of , and the adsorption mechanism was different. The adsorption capacity of by FeCl3 modified biochars mainly increased the specific surface area and micropore volume. The adsorption of ammonium nitrogen after KOH modification primarily depended on the wealthy oxygen-containing functional groups. The adsorption effect of ammonium nitrogen modified by KOH was better than that of biochar modified by FeCl3.

Study on the transformation of gaseous selenium during the cooling process of coal-fired flue gas.

Understanding the transformation of Se during the flue-gas cooling process is important for controlling Se emissions. By analyzing the thermal stability of Se in ash collected from power plant dust collectors, physical migration was found to be the main pathway by which gaseous Se transformed into ash during the flue-gas cooling process. The dynamic curves were obtained for SeO2 adsorption by ash at 200-900℃. The adsorbed Se amount first decreased, increased, and then decreased with increasing adsorption temperature (400℃ and 600℃ were the two turning points). By comparing the adsorption characteristics of different ash and minerals and performing a speciation analysis of Se and an elemental distribution characterization after adsorption, the adsorption mechanism of gaseous Se was proposed. In the medium-high temperature range (above 500℃), SeO2 was chemically adsorbed by ash through CaO and CaSO4, generating CaSeO3 and CaSeO4, respectively; the thermal stability of CaSeO4 was weaker than that of CaSeO3. In the low temperature range (below 500℃), SeO2 was adsorbed by ash mainly through physical adsorption of unburned carbon, accompanied by a small amount of chemical adsorption of CaO.

Modification of the Textural Properties of Chitosan to Obtain Biochars for CO2-Capture Processes.

Three chitosans with different morphologies have been used (commercial chitosan powder, chitosan in film form and chitosan in globular form synthesized by the freeze-dried method) for the synthesis of biochars. The pyrolytic treatment has revealed that the biochar synthesized from the chitosan formed by the freeze-dried method reaches the highest CO2-adsorption capacity (4.11 mmol/g at 0 °C and a pressure of 1 bar) due to this adsorbent is highly microporous. Moreover, this biochar is more resistant to the pyrolytic treatment in comparison to the biochars obtained from the commercial chitosan and chitosan in the form of film. CO2-adsorption studies at different temperatures have also shown that the adsorption capacity diminishes as the adsorption temperature increases, thus suggesting that the adsorption takes place by a physical process.

Removal of As2O3 in coal-fired flue gas by metal oxides: Effects of adsorption temperature and flue gas components

Arsenic emitted from coal-fired power plants has attracted widespread attention. Metal oxides are promising adsorbents for arsenic removal, but the influence laws and mechanisms of temperature and flue gas components on their arsenic removal performance are unclear. In this work, systematic research on the effects of adsorption temperature and flue gas components on As2O3 removal by Fe2O3, CaO, and γ-Al2O3 was conducted. The results show that As2O3 removal ability satisfies Fe2O3 > CaO > γ-Al2O3 at 300–900 °C, which is mainly related to their basic site strength. At 500 °C, Fe2O3 has the largest As2O3 removal capacity (adsorption capacity: 158.4 μg/g; removal efficiency: 84.68%). Increasing adsorption temperature is beneficial to the transformation of arsenic to high-valent arsenic (As(V)) on the surface of Fe2O3, CaO, and γ-Al2O3. Low-concentration SO2 will compete with As2O3 for adsorption on the three metal oxides surface, which thereby inhibits their As2O3 removal ability. The presence of NO has an obvious inhibitory effect on the As2O3 removal of Fe2O3, CaO, and γ-Al2O3, which is little affected by the change of NO concentration. Fe2O3 is a metal oxide adsorbent with strong arsenic removal potential. Compared with basic simulated flue gas (BSFG) components, the presence of SO2, NO, and SO2+NO in the simulated flue gas all inhibits the adsorption of As2O3 by Fe2O3. Finally, future work on arsenic removal from coal-fired flue gas adsorbents is presented. This work has important engineering applications and theoretical research guiding significance for the development of high-performance arsenic removal adsorbents.

Low-temperature hydrothermal modification of waste paper fiber adsorbent to enhance removal benzothiophene sulfide efficiency from oil: kinetics and equilibrium study

Thiophene sulfide is difficult to be removed by hydrodesulfurization. In this study, ZnCl2-waste paper fiber activated carbon was used as adsorbent to remove thiophene sulfide from simulated oil by hydrothermal modification. Under the optimum condition of ammonia modification, the adsorption capacity of modified adsorbent to BT is 14.8 mg S/g, 2.98 times that of unmodified. BET, FTIR and Boehm analysis showed that the mesopore volume of ammonia modified adsorbent increased by 96.62% and the mesopore ratio increased from 12.58% to 43.40%, which was conducive to improving the adsorption rate. After modification, the basic groups on the surface of the adsorbent increased by 44.3 times, and –NH3+, –OH and –NH2 enhanced the electron attraction and hydrogen bonding force between the adsorbent and BT molecule. Adsorption isotherms, adsorption kinetics and adsorption thermodynamics show that the adsorption process is spontaneous, entropic and exothermic. The pseudo-second-order kinetic rate constant increases with the increase of adsorption temperature, indicating that the increase of temperature is beneficial to accelerate the adsorption rate. The adsorption desulfurization process follows the mechanism of single and multilayer adsorption mixing. The results of this study can help to reveal more clearly that biobased activated carbon can be modified to adsorb thiophene sulfide.

Electrochemical Application of Structured Color Nanotextile Materials in Garment Design

In order to improve the color saturation of textile structured chromogenic photonic crystals, this paper proposes that the dye adsorbed PSt structural elements (reactive dyes/PSt microspheres) on the outer surface can be used to construct electrochemically structured chromogenic photonic crystals on mulberry fabrics by digital printing. In this method, the adsorption conditions and adsorption model of dyes on the surface of PSt colloidal microspheres were studied. The structure and morphology of reactive dyes/PSt microspheres, the arrangement of the obtained photonic crystals, and the structural chromogenic effect were characterized. The results showed that the amount of dye adsorbed on the surface of microspheres increased significantly with the increase of adsorption temperature from 25°C to 65°C. When the adsorption temperature continued to rise to 75°C, the dye adsorption capacity on the surface of PSt microspheres did not increase significantly. The adsorption model accords with the Langmuir model; reactive dye/PSt microspheres have a typical core-shell structure, and the particle size of the microspheres is slightly larger than that before adsorption. Conclusion. The reactive dye/PSt photonic crystal chromogenic electrochemical structure constructed on the surface of white silk fabric has a regular and orderly arrangement of microspheres, showing bright structural color.