Regeneration Performance Research Articles

Analysis of Rheological Properties and Regeneration Mechanism of Recycled Styrene-Butadiene-Styrene Block Copolymer (SBS) Modified Asphalt Binder Using Different Rejuvenators.

The regeneration performance of an aged styrene-butadiene-styrene block copolymer (SBS) will be significantly influenced by different rejuvenators. The objective of this study was to comparatively investigate the regeneration effect of different SBS-modified asphalt regenerators on aged SBS-modified asphalt. Four types of different regenerant formulations were selected. The optimal rejuvenator content was determined firstly using conventional performance tests. The rheological properties of the aged SBS-modified asphalt binder were evaluated by multiple stress creep recovery (MSCR) experiments. Subsequently, the regeneration mechanism of the SBS-modified asphalt binder was investigated using thin-layer chromatography-flame ionization detection (TLC-FID) and Fourier transform infrared spectroscopy (FTIR). The results showed that the rejuvenator had a certain recovery effect on the penetration, softening point, and ductility of the SBS-modified asphalt binder after aging. The SBS-modified rejuvenating agent was the most favorable among the four types of rejuvenators, where a rejuvenator dosage of 12% showed the optimal rejuvenation effect. The addition of regenerators could appropriately improve the elastic deformation capacity of the aged asphalt binder. The epoxy soybean oil in the regenerant reacted with the aging SBS-modified asphalt binder, supplementing the lost oil in the aged SBS-modified asphalt binder, dispersing the excessive accumulation of asphaltene, and making the residual SBS swell again. The viscoelastic properties of the aging asphalt binder were improved by adjusting the content of components and functional groups to achieve the purpose of regeneration.

Exploring the influence of different precursor materials on the catalytic performance and deactivation characteristics of iron-loaded biochar catalysts for the catalytic cracking of toluene

This study employed rice husks (RH), corn stalks (CS), and camphor leaves (CL) as biomass sources to prepare iron-loaded biochar catalysts, elucidating the key relationships between these biomass materials, their catalytic performance, and their resistance to deactivation in toluene. Experimental results indicated that the carbon deposits in the three spent catalysts are primarily composed of inert carbon (Cγ). The carbon peaks in these deposits primarily consisted of CO, CC, and CO structures, with varying proportions across the different types of spent catalysts. Specifically, the RH spent catalyst exhibited the highest relative content of the CO structure at 13.49 %, the CS spent catalyst showed the highest relative content of the CC structure at 89.19 %, and the CL spent catalyst displayed the highest relative content of the CO structure at 5.57 %. Fe2+ was the predominant species on the surfaces of all three spent catalysts, accounting for over 50 % in each case. Fe3C was detected on the surfaces of the CS and CL spent catalysts but was absent on the RH spent catalyst. After 80 min of reaction, the carbon deposition rate of the CL catalyst was 8.15 %, with a catalytic cracking efficiency of 28.04 %, making it the most effective overall. This effectiveness was attributed to the CL catalyst's highest oxygen vacancy intensity, where the abundant oxygen source effectively promoted the catalytic reaction of toluene and inhibited carbon deposition. After three consecutive regeneration cycles, the catalytic cracking efficiency of the CL catalyst remained above 70 %, demonstrating strong cyclic regeneration performance. This study provides theoretical insights into the effective utilization of agricultural and forestry waste, contributing to environmental protection.

Antioxidative implant coating with anti-infection and osteogenesis time-dependent bifunction for synergistic promotion of osteointegration

Infection and poor osteogenesis are two major causes of implant failure. Surface modification strategy provides solutions to the above problems. However, the functional requirements at different biological stages during infectious bone repair and the oxidative stimulation caused by reactive oxygen species (ROS) in an inflammatory environment pose challenges to the existing approaches. Layer-by-layer (LbL) self-assembly realizes layer by layer superposition and time-dependent acting of different bioactive components, but is demanding to functional groups. Tannic acid (TA) owns abundant phenolic hydroxyl groups, endowing various firm chemical bindings and excellent antioxidant property. To this end, we developed a time-dependent and antioxidant multifunctional coating via TA mediated LbL self-assembly. This layer exhibited higher ROS removal capacity and stronger binding ability. Furthermore, it showed rapid and excellent antibacterial ability of over 85 % against Staphylococcus aureus and Escherichia coli at 24 h, which additionally promoted osteogenic differentiation in vitro in long term. Moreover, the coating exhibited outstanding antibacterial and bone regeneration performance in vivo as well. Thus, this study is expected to provide an antioxidant and time-dependent multifunctional platform for surface modification engineering of dental and orthopedic implantation, as well as other potential biological material designs.

In-situ co-growth of ZIF-8-derived bio-carbon spheres with meso-macroporous hierarchy for stable and rapid carbon dioxide capture

Efficient carbon dioxide (CO2) capture from post-combustion flue gases is crucial for industrial applications. Adsorbents with high adsorption capacity, exceptional stability, high selectivity, and low cost are essential to meet these requirements. In this study, we present the synthesis of bio‑carbon spheres derived from zeolitic imidazolate framework-8 (ZIF-8) using a macro-fluidic technique. The bio‑carbon spheres integrate ZIF-8 for structural orientation and chitosan for the directional assembly of ZIF-8, thereby addressing the limitations of low strength in chitosan-derived carbon spheres and the challenge of macroscopic shaping of ZIF-8 particles. Additionally, the incorporation of ZIF-8 and the enhancement of the carbon skeleton increased the meso-macroporosity, improving CO2 transport and adsorption performance. The bio‑carbon spheres demonstrated a 46.9% higher CO2 adsorption capacity (101 kPa, 1.40 mmol·g−1) compared to pure chitosan carbon granules (101 kPa, 0.96 mmol·g−1) and a 17.8% faster mass transport rate compared to ZIF-8 carbon particles. Moreover, the bio‑carbon spheres exhibit a low wear rate in a simulated fluidized bed, good thermal stability, and stable cyclic regeneration performance. This study offers a novel strategy for developing industrially applicable adsorbents with hierarchical pore structures to enhance CO2 capture.

Eco-friendly thiol-functionalized magnetic oxygenous carbon nitride nanocomposites for effective elimination of heavy metals

The increased pollution of water resources by toxic heavy metals poses a huge threat to the aqueous ecosystem. Since the low concentrations of heavy metals are often highly toxic but difficult to remove, novel efficient adsorbents still need to be explored. Herein, the superparamagnetic thiol-functionalized oxygenous carbon nitride nanocomposite (CNO/Fe3O4-SH) with multifunctional groups such as –NH2, –OH, –SH, and –COOH was fabricated by a simple and eco-friendly method. The maximum adsorption capacities of Pb2+, As3+, and Cd2+ ions on CNO/Fe3O4-SH at pH = 6 were 80.79, 71.78 and 66.19 mg/g, respectively, when their equilibrium concentrations were 20 mg/L. Under the equilibrium concentration below 0.01 mg/L, the adsorption capacities of these heavy metals over CNO/Fe3O4-SH were much higher than those of other adsorbents. The competitive adsorption investigations showed that the adsorption order in polymetallic solutions was Pb2+ > As3+ > Cd2+. Adsorption kinetics and isotherms studies indicated that the adsorption of Pb2+, As3+ and Cd2+ by CNO/Fe3O4-SH was attributed to monolayer adsorption and the adsorption process was controlled by chemical adsorption. The thermodynamic experiments showed that the adsorption processes were spontaneous and endothermic. After six adsorption/desorption cycles, CNO/Fe3O4-SH maintained its original morphology and adsorption ability, indicating its excellent regeneration performance, which had significant potential application in the decontamination of trace heavy metal ions in water.

In Situ Growth of Nitrogen-Doped Fluorescent Carbon Dots on Sisal Fibers: Investigating Their Selective and Enhanced Adsorption Capabilities for Methyl Blue Dye.

Preparing a biomass adsorbent material with high-absorption performance but low cost plays a vital role in wastewater treatment. In this study, a novel nitrogen-doped sisal fiber-based carbon dots (SF-N-CDs) composite was prepared by directly growing carbon dots (CDs) on sisal fiber (SF) using a microwave method with polyethyleneimine (PEI) as a raw material. The prepared SF-N-CDs were characterized using FTIR, XRD, Contact angle(CA), TGA, XPS, and SEM. The results revealed that the CDs were successfully grown on SF. The adsorption properties of SF-N-CDs were significantly enhanced when they adsorbed methyl blue (MeB) dye. Specifically, the adsorption of MeB by SF-N-CDs was up to 619.7mg/g, which was about 2.6 times higher than that of raw SF. This implied that the introduction of CDs increases the adsorption site, thus enhancing the adsorption capacity. Analysis on kinetics and thermodynamics of MeB adsorption by SF-N-CDs revealed that the adsorption process followed the Langmuir isotherm model and were consistent with both kinetic models. It signifies that the adsorption involves both physical and chemical adsorption processes. Further, the SF-N-CDs maintained a removal rate of 70.9% after six adsorption-regeneration cycles, demonstrating good regeneration performance. Moreover, the SF-N-CDs could selectively separate MeB from a mixture of rhodamine B and saffron T. Consequently, the findings of this study suggest that SF-N-CDs are promising adsorbents for anionic dyes.

Interpreting the removal behaviours of aniline and 3,4-diaminotoluene on aromatic carbon-rich magnetic polymer: Statistical modelling, DFT quantitative calculations and new perspectives

The widespread presence of harmful and stubborn amine organic contaminants in aquatic environments motivated the exploration of efficient technologies for alleviating their serious environmental crisis. Herein, the recyclable magnetic Schiff base polymer (Fe3O4-TENE) with satisfactory and promising capacity in treating aniline and 3,4-diaminotoluene as representative amine organic contaminants was fabricated via a simple in-situ polymerization method, which combined the magnetic separability advantage of magnetic oxides with the abundant aromatic carbon content properties of Schiff base polymer. Multiple characterization methods verified the effectiveness of the in-situ polycondensation coating reaction and analyzed the physicochemical properties of Fe3O4-TENE. The Fe3O4-TENE possessed abundant homogeneous reaction sites and excellent regeneration performance, multiple diffusion driving forces and micro-mechanisms co-participated in the removal reaction. The adsorption pathway, underlying reaction mechanism and the most probable bonding system were identified based on the statistical modelling and DFT quantitative calculations. Especially, the visible electrostatic potential molecular and molecular orbitals verified the π-π interaction and electrostatic forces greatly contributed to the removal reaction. The Driving forces – Challenges – Breakthrough – Application framework was proposed for comprehensively assessing the possible environmental application of Fe3O4-TENE. Overall, this work not only provides important insights into the utilization of magnetic polymer composite to alleviate ecological and environmental risks caused by amine organic pollutants, but also contributes to an in-depth excavation of the bonding types and removal mechanisms from both micro and macro perspectives.

MOF-5 anchored polymer@carbon core–shell nanofibers for efficient removal of chlortetracycline from aqueous solution

Antibiotics excreted by human or animal may contain un-degradable residues, which form high concentration accumulation in water, leading to seriously harmful effects on the environment. Herein, MOF-5 anchored polymer@carbon core–shell nanofibers (MAPC) are fabricated via the electrospinning-hydrothermal synthesis and used for high efficiency removing chlortetracycline (CTC) from water. The anchored MOF-5 enhances the adsorption ability of hydrothermal carbon core–shell nanofibers. The MAPC nanofibers exhibit 395.87 mg/g of adsorption capacity for CTC removal process, which well fitted with Freundlich isotherm model and pseudo-second-order kinetic model. After nanofiber membrane filtering, the removal efficiency of CTC is nearly 100 % at the concentration of 5 mg/L. And the chemical oxygen demand (COD) concentration of CTC is reduced from 156.72 mg/L to 50.39 mg/L, that is below the pharmaceutical wastewater discharge standard. In addition, MAPC exhibits high flux and good regeneration performance. This work gives a typical strategy of feasible preparation of high efficiency MOFs anchored carbon-based nanofiber adsorbent towards the pharmaceutical wastewater treatment.

Deicing performance analysis of the solution regenerator unit using freeze concentration

During the process of regeneration, freeze concentration exhibits high energy efficiency. The performance of regeneration is directly affected by the separation effect and salinity level of ice under different regeneration conditions. In order to evaluate the energy efficiency of deicing under different conditions, a freeze concentration solution regenerator unit was constructed and equipped with a heat pump system. Based on experimental data, the theoretical model of average distribution coefficient and deicing energy consumption is established to study the influence of ice separation efficiency and solute residue on the deicing energy consumption. Results show the ice salinity reduces the effect of ice amount on regeneration concentration. The increase of icing difficulty and ice salinity are the two main reasons that affect the decrease of deicing operation efficiency of high concentration solution. As the amount of ice separating decreases, the deicing energy efficiency is more sensitivity to the solute residue. The reduction rate of energy consumption is equal to the proportion of influence of solute residue in deicing energy efficiency. From 6%, 8%, 10% and 13% concentration, solute residue increases the deicing energy efficiency by an average of 2.4%, 3.4%, 4.6%, and 6.6%, respectively. The influence of solute residue on deicing operation efficiency can be reduced by increasing separation efficiency. The deicing energy consumption diagram of anti-frost solution freeze concentration system is proposed. The investigations will be helpful to improving the energy efficiency and steadiness of the heat pump with freeze concentration.

Study on Methylene Blue Adsorption Properties of Biochar/Montmorillonite Composites

The textile printing and dyeing industry, as one of the important pillars of the global economy, has become an environmental problem that needs to be solved because of the increasingly serious pollution of dye wastewater generated during its production process. Dye wastewater not only contains high concentrations of organic dyes, but also often accompanied by heavy metal ions, additives and salts and other pollutants, if discharged directly without effective treatment, will seriously pollute the water body, destroying the ecological balance, and affecting the survival and health of human beings and aquatic organisms. In order to deal with the problems of serious pollution, large discharge and high cost of dye wastewater, it is necessary to develop an efficient, economic and environmentally friendly wastewater treatment system. It is particularly important to develop efficient, economical and environmentally friendly wastewater treatment technologies. Adsorption is considered as a promising method for wastewater treatment. In this study, we focused on the development of new and efficient adsorbent materials. Taking methylene blue, a typical dye, as an example, we skillfully composited modified biochar with montmorillonite, a natural mineral material, through pyrolysis and intercalation strategies, and conducted in-depth investigations on the effects of the composites on the adsorption of methylene blue in water, the factors affecting the regeneration performance of the adsorbents, and the thermodynamic characteristics of the adsorption. The effect of the composite material on the adsorption of methylene blue in water, the factors affecting the regeneration performance of the adsorbent and the adsorption thermodynamic characteristics were investigated in depth, with a view to providing certain theoretical and practical references for the effective treatment of dye wastewater.

Facile and scalable synthesis of long-life porous MgO-nanofiber functionalized biochar adsorbent from magnesite for phosphate recycling

The recycling of phosphate from wastewater using regenerable and highly efficient MgO-modified biochar for Mg-P fertilizer application is of great interest. However, the practical application of MgO-modified biochar for the removal and recycling of phosphate is hindered by its short-recycled service-life. Herein, a facile yet scalable method is proposed to fabricate porous MgO nanofiber-functionalized biochar (PMgNF-BC) with enhanced phosphate adsorption and regeneration performances from wastewater using waste biomass and magnesite. The as-prepared PMgNF-BC exhibited the maximum phosphate adsorption capacities of 594.53, 661.57, and 725.43 mg/g at 298.15 K, 308.15 K and 318.15 K, respectively. More importantly, PMgNF-BC demonstrated excellent regeneration performance with the removal efficiency of 84.2 % after eight regeneration cycles. Furthermore, the regenerated PMgNF-BC exhibited the well-preserved fiber shape of MgO on BC, enabling splendid regeneration performance. This work validates PMgNF-BC as a sustainable adsorbent for recycling phosphorus from wastewater, addressing the urgent need for synthesizing biochar with high regeneration performance.

A design kinetic and hydrodynamic study of a coupled dual fluidized bed MTO reactor-regenerator system

The methanol-to-olefin (MTO) process, employing a dual-fluidized bed system, has introduced a new and reliable route for producing light olefins. This study intends to employ a comprehensive approach to simultaneously design and evaluate the reactor and regenerator performance. Namely, an inclusive design for a pilot-scale MTO system, encompassing the reactor, regenerator, interconnected catalyst transfer pipelines, and other critical operational aspects, is presented. The computational fluid dynamics (CFD) method using the Eulerian-Eulerian model was used to evaluate hydrodynamics, while the coupled reactor-regenerator kinetic model was developed by combining reaction kinetics with the two-phase model. The models were validated against experimental data and demonstrated a promising agreement. More importantly, an innovative procedure was devised to apply these modelling techniques to design this dual-fluidized bed system—the final design for the 10 kg catalyst inventory in the reactor at the pilot scale. The system achieves methanol conversion of 98.87 %, with ethylene and propylene product mass fractions of 45.51 % and 37.79 %, respectively.

Coadsorption mechanisms of copper and sulfamethoxazole by functionalized cellulose: A kinetic and DFT study

In order to address the issue of compound pollution from heavy metals and antibiotics in aquatic environments, multibranched functionalized cellulose materials (DACS) with abundant adsorption affinity groups (such as amino, carboxyl and imine groups) were prepared by oxidation, etherification and grafting. The maximum adsorption capacities of DACS for copper (Cu) and sulfamethoxazole (SMZ) were 42.27 and 117.92 mg/g, respectively. In addition, its excellent pH buffering capacity, resistance to coexisting interfering substances and great regeneration performance of up to 91 % after 5 cycles. In the coadsorption experiment, the multibranched structure strengthened the bridge effect during the coadsorption process, and weakened the inhibition of SMZ adsorption caused by competition. Kinetic models and error functions analysis showed that PNO model and F&S model were the most consistent with the adsorption process, and the limiting step of adsorption was the external diffusion of Cu and SMZ around the surface of DACS. Moreover, the density functional theory (DFT) was used to quantitatively calculate the adsorption binding energy of multiple sites on DACS, and clarified the adsorption tendency of DACS as electron donors for Cu and as acceptor for SMZ. In addition, the binding energy of sequential adsorption was greater than that of single and binary adsorption, and the binding stability of SMZ was significantly increased in sequential adsorption for the increasing of binding energy. The electron exchange process in the adsorption showed that SMZ played a bridging role in the binary adsorption, while Cu was the main reaction part of the complex adsorption.

The Faradaic-Induced hybrid capacitive engine enables high-performance selective defluorination via capacitive deionization

Fluoride (F-) contamination has become a pressing environmental concern owing to its extensive origins and severe toxicity. Capacitive deionization (CDI) emerges as a promising technique for efficient defluorination, with the development of electrode materials being pivotal to its efficiency. Herein, we present a novel design of Sb-decorated N-rich carbon composites (SNTPCs) for the formation of a hybrid capacitive engine that integrates Faradaic-induced pseudocapacitance and electrical double layer capacitance, enabling efficient F- electrosorption. This approach features a distinctive N-rich carbonaceous laminar framework that not only guarantees rapid ion diffusion and electron transfer but also provides a dense electrical double layer for F- storage. The Sb sites are electrically stimulated to release the intrinsic affinity with F-, forming the Faradaic Sb-F bonds. The SNTPC2 electrode exhibits the exceptional saturation removal capability and dynamic electrosorption capacity for defluorination, reaching 178.58 and 34.77 mg F/g at 1.2 V respectively, which exceeds most reported F- capture electrodes. It also demonstrates excellent selectivity towards F- in complex conditions and exhibits effectiveness across a wide range of pH values. Additionally, the utilized electrode performs outstanding regeneration performance after 20 consecutive cycles. This study provides innovative perspectives for the effective elimination of fluoride pollution in aquatic environments.

Adsorption of Sudan II dye onto fly ash/polyacrylic acid/melamine composite: Factorial design optimization, reusability performance and removal mechanism

This study aims to develop fly ash (FA) modified with melamine (M) and polyacrylic acid (PAA) for strong adsorption of Sudan II dye from aquatic media. Surface functionality and morphological characteristics of the prepared FA/PAA/M composite were characterized using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) techniques. A factorial design model was applied to estimate the influence of adsorption and interactions of adsorption parameters such as contact time, pH, adsorbent dose, and initial dye solution. The significant interactions among these factors were investigated by analysis of variance (ANOVA). The isotherm modeling data indicated the Langmuir adsorption capacity for raw FA and FA/PAA/M composite as 57.4 and 142.3 mg/ g, respectively. This means that the Sudan II dye adsorption capacity of FA was boosted more than one time after modification with PAA/M polymer due to increased affinity towards the dye molecules by amide and hydroxyl groups onto the surface of the composite adsorbent. The adsorption kinetic evaluation revealed that the Sudan II dye adsorption by the composite was well-defined by the pseudo-second-order model. The produced FA/PAA/M showed a reasonable regeneration performance of 72/66 % after the adsorption/desorption processes were repeated four times. The adsorption mechanism between dye molecules and surface functional groups of the composite was described by hydrogen bonding interactions, π- π interactions, metal-π interaction and electrostatic attractions. The results indicated that the composite could be a promising adsorbent for dye removal from industrial wastewater due to its strong adsorption capacity, easy preparation, and good reusability performance.

Efficient removal of direct dyes by SA-Er biopolymer gel spheres: Equilibrium isotherms, kinetics and regeneration performance study

Biomass-based adsorbent materials are characterized by their low cost, environmental friendliness, and ease of design and operation. In this study, biomass-based hydrogel microspheres erbium alginate (SA/Er) with high stability and adsorption properties were prepared by a one-step synthesis method. The prepared materials were characterized and analyzed by SEM-EDS, XRD, TGA, FT-IR, UV–Vis, BET-BJH and XPS, and the adsorption performance of SA/Er was investigated for high concentrations of azo dyes in water. The results showed that the adsorption performance of SA/Er on the azo dyes of direct violet N (DV 1) and direct dark green NB (DG 6) with concentrations of 850 mg/L and 1100 mg/L under the optimal conditions was very high, and the adsorption amount could be up to 692 mg/g and 864 mg/g, respectively. The adsorption process was in accordance with the quasi-secondary kinetic model, which was accomplished by physical and chemical adsorption; the Langmuir isothermal model was able to better respond to the adsorption equilibrium, and the adsorption was dominated by the adsorption of surface monolayers; after seven desorption cycles, the removal of both azo dyes by the adsorbent material could reach >79.7 %. Combined with the results of FT-IR, UV–vis and XPS analysis before and after the adsorption, it was revealed that the adsorption of SA/Er with the dye molecules mainly consisted of hydrogen bonding, electrostatic adsorption and surface complexation, which resulted in the significant adsorption effect on the two azo dyes, and the above results can provide a reference for the treatment of dye wastewater.

Adsorption of titanium-aluminum layered hydroxides for removal of fluorine at low concentrations in water

Layered double hydroxides have good application prospects in the fields of water treatment and defluoridation. In this study, Ti-Al layered hydroxides (Ti-Al LDHs) were synthesized by the co-precipitation method at a Ti/Al molar ratio of 2/8 and a medium solution pH of 6.0. The SEM, XRD, and BET results showed that the Ti-Al LDHs showed a uniform stacking of lamellar structure and existed mainly in dispersed amorphous form, with a wide pore size and a larger specific surface area (108.34 m2/g). The results of adsorption experiments showed that the highest capacity could reach 116.2 mg/g, and the adsorption adsorption of Ti-Al LDHs on fluoride was more in line with the proposed second-order model, and the adsorption isotherm was more in line with the Langmuir model.In addition, Ti-Al LDHs can be applied in a wide pH range (4−10), have strong resistance to anionic competition, and have good regeneration performance after five adsorption-desorption cycles where the adsorption capacity is still equivalent to 73 % of the initial capacity. From the FTIR and XPS results, the adsorption process was mainly attributed to ion exchange, electrostatic attraction and surface complexation. Therefore, Ti-Al LDHs is a layered hydroxide fluoride removal adsorbent with good application prospects.

Combined experimental and theoretical studies on adsorption characteristics of graphitic carbon nitride for flue gas molecules

Graphitic carbon nitride (g-C3N4) is a novel selective adsorbent for separation of Hg0 and Hg2+, which plays a pivotal role in mercury continuous emission monitoring systems (Hg-CEMS). However, some of the flue gas components may interfere with their binding characteristics with g-C3N4. This study employs the density functional theory (DFT) and experimental method to investigate the adsorption behavior of gas components on g-C3N4 and elucidates the intrinsic driving forces behind these interactions and assesses their impact on separation of Hg0 and HgCl2. The binding energies of H2O, SO2, CO2, NO, and O2 molecules on g-C3N4 are −0.575 eV, −0.530 eV, −0.309 eV, −0.246 eV, and −0.238 eV, respectively. The electronic structure and weak interaction analyses indicate that these interactions are primarily van der Waals forces caused by multi-atomic interactions. In contrast, the binding energy between HCl and g-C3N4 is −0.557 eV, primarily controlled by weak H-N covalent bonds. The co-adsorption results indicate that flue gas molecules exert negligible effects on the binding of HgCl2 to g-C3N4 because the changes in binding energy are within 0.15 eV. The experimental results verify that under practical operating conditions, the adsorption of H2O, HCl, SO2, CO2, NO, and O2 on g-C3N4 is below 0.1 %, demonstrating those components do not interfere with the separation of Hg0 and HgCl2 by g-C3N4, nor do they affect the regeneration performance of g-C3N4. This study provides new insights into the development and practical application of separation and conversion modules in Hg-CEMS technologies.

Examining collaborative planning processes and outcomes in urban regeneration: A deliberative turn in China?

Collaborative planning practices have recently emerged in China to deal with the complexity and conflicts of interest in urban regeneration. Building on the concept of authoritarian deliberation, this study develops a conceptual framework to examine the reasons for initiating collaborative planning, and its processes and outcomes. Through the case study of Guangzhou’s Enning Road micro-regeneration project, this research deepens understanding of collaborative planning in an authoritarian context. It reveals that deliberative methods were used by the local government to mitigate conflicts and improve governance performance in urban regeneration. While deliberations in an authoritarian context met many process criteria of collaborative planning, the collaborative processes had limited influence on planning outcomes. In addition, this study marks the increased level of participation in Chinese urban regeneration and discusses the limitation of deliberative practices in an authoritarian context. Lastly, this study reflects on the adoption of collaborative planning approaches as a state strategy to balance various interests and reinforce its dominance in market-driven urban regeneration, ultimately to achieve goals beyond economic benefits.

Preparation and Selective Adsorption Performance of the Carboxymethyl Salix psammophila Wood Powder-Imprinted Membrane for Tetracycline.

Carboxymethyl Salix psammophila wood powder-imprinted membranes (CMSM-MIPs) were prepared by using wet spinning technology and molecular-imprinting technology for the selective removal of tetracycline from wastewater. Scanning electron microscopy, X-ray diffraction, thermogravimetry, and X-ray photoelectron spectroscopy characterizations demonstrate that CMSM-MIPs retain the membranous structure of Carboxymethyl Salix psammophila wood powder membranes, successfully encapsulate thin layers of imprinted polymers on the membrane surface, and exhibit excellent thermal stability. The adsorption results showed that CMSM-MIPs had the highest selective adsorption capacity for tetracycline, which was 253.8 mg/g. In addition, the adsorption capacities for oxytetracycline and chlortetracycline were 208.8 and 188 mg/g, respectively. It can be observed that CMSM-MIPs not only exhibit a high adsorption capacity for tetracycline but also demonstrate good adsorption capacities for oxytetracycline and chlortetracycline. The experimental results showed that CMSM-MIPs were best fitted with pseudo-second-order kinetics and most consistent with Freundlich fitting. The regeneration experiment showed that CMSM-MIPs still had good regeneration performance after 5 regeneration cycles. In conclusion, the CMSM-MIPs can not only have the natural adsorption performance of Salix psammophila wood powder but also give it higher selectivity through molecular imprinting, so as to achieve efficient removal of target organic pollutants in water.