The development of functional porous crystalline materials driven by physical adsorption for deep removal of CO₂ impurities from crude syngas is an important way to produce high quality syngas. Although well-known metal organic framework (MOFs) has made many breakthroughs in CO₂ capture, it often suffers from the key problems of decreasing adsorption capacity and low product purity in μL/L CO₂ capture and non-room temperature CO₂/CO purification. Based on this, the classical Mg-MOF-74 (1a) was taken as the research object and aminopyrazine motif (apz) could be successfully confined to the 1a channel (1a-apz) by a facile steam-coordination strategy. The results showed that 1a-apz had outstanding separation performance for 1/99 CO₂/CO mixture, and the purity and yield of CO were 99.99% and 70.5L/kg, respectively, at the operating temperature of 348K. Crude syngas containing the mixtures of H₂/N₂/CH₄/CO/CO₂ (46/18.3/2.4/32.3/1, volume fraction) confirmed that 1a-apz remained prominent trace CO₂ capture performance. In situ gas-loaded crystal diffraction, temperature-dependent spectroscopy tests, high-resolution synchrotron radiation X-ray diffraction and theoretical calculations revealed that the apz motif in 1a-apz structure not only had "adaptive adsorption" behavior at the appropriate threshold temperature, but also could effectively regulate the local electrostatic potential of pore surface and confine the functionalized multiple adsorption sites. Thus, yielded "induction-fit" behavior between CO₂ and pore surface would form, which was similar to the "enzyme-substrate" identification process in the biological world.

Research on nitrogen-based substances, including elemental nitrogen and compounds containing a nitrogen atom, has attracted much attention, particularly for ammonia synthesis, hydrogen generation and denitration. These studies hold immense potential for applications in advancing new energy sources, mitigating environmental pollution and achieving carbon neutrality. This article introduced the concept of "N1 chemistry", highlighted several notable examples in this field, discussed significant advancements in ammonia synthesis, hydrogen generation and denitration, and presented an outlook on the future development of "N1 chemistry".

It is a thorny problem for micro-particle deposition based on gas-solid flow. Particle deposition is a common physical phenomenon but with more negative impact, such as the wear of turbine blades caused by sand particles, scale corrosion caused by fly ash particles on boiler heat exchange surface and so on. Although the continuous optimization of soot blowing scheme has greatly reduced the negative impact of fly ash deposition, there are still some uncontrollable problems. Therefore, it is of great significance to summarize and analyze the law of particle adhesion behavior to suppress particle deposition in engineering. Based on the main background of boiler fly ash deposition, this paper expounded the mechanism and characteristics of particle adhesion dominated by inertial impact, reviewed the research work on critical deposition criteria in recent years, focused on the analysis of the influence of deposition factors on the criteria of particle adhesion/rebound, and summarized the main criteria of particle detachment. By comparing the problems and connections of relevant criteria horizontally, the research status and existing problems of particle adhesion criteria was explained, which provided technical and theoretical support for the effective suppression of boiler deposition and the promotion of particle detachment theory.

To investigate the effect of the above phase separation structure on the boiling pressure drop of the flow within the microchannels, an experimental section of the microchannels with the phase separation structure was machined using CNC technology. The pressure drop of two (porous/low-porous) phase separation structures and a normal microchannels without venting holes were analyzed at an inlet temperature of 70℃, a mass flow rate of 121.25kg/(m²·s) and a heat flow density of 76.61—150.70kW/m² using an aqueous glycerol solution with a mass fraction of 30% as the experimental working medium. To examine how different phase separation structures of microchannels affect the length-to-diameter ratio (l/w) of confined bubbles, the bubble dynamics in the channels were visualized and a gas phase separation coefficient was employed to quantify the growth behavior of confined bubbles in the channels. The experimental results showed that the phase separation structure could improve the total pressure drop of the two phases in the channels. In the porous, less porous, and ordinary microchannels, the larger the gas phase transfer area of the microchannels, the larger the gas phase separation coefficient, the smaller the length-diameter ratio of the confined bubbles in the channels, the smaller the total pressure drop loss of the two phases, and could improve the system reliability. In addition, by increasing the pressure difference between adjacent channels and adjusting the appropriate pressure switching period, the gas phase transfer rate of the phase separation membrane could be further improved and the total pressure drop of the two phases in the channels could be slowed down. This study could provide a new design idea for the improvement of flow boiling pressure drop in microchannels.

The heat transfer enhancement of phase change by composite porous structure is an important topic in the fields of energy and chemical industry. Based on the concept of vapor-liquid synergetic transport, two-layer hierarchical structure nested with two-dimensional nano-porous chain on the silicon substrate was processed by femtosecond laser orthogonal scanning method. The subcooled pool boiling heat transfer performance of the porous structure was experimentally investigated. The experimental medium was HFE-7100. Compared with a smooth surface, the wall superheat of the two-layer porous structure at the onset of nucleate boiling was reduced from 16.7K to 12.3K at liquid subcooling of 35K, and the ratio is 26.3%. The maximum critical heat flux was increased by 128.7%. At the same time, the enhancement mechanism of boiling heat transfer was studied by observing bubble behaviors with a high-speed camera. It was found that a large number of interconnected cavities formed on the surface and inside the porous structure increase the effective nucleation site density. And nano-pores and two-layer structure provided vertical and horizontal liquid replenishment. The bubble size was smaller, and the departure frequency was faster under high heat flux. The increased nucleation site density and the vapor-liquid synergetic transport enhanced the micro convection and the thin liquid film evaporation, which effectively enhanced the boiling heat transfer coefficient and critical heat flux.

The bubble dispersion characteristics were investigated by computational fluid dynamics (CFD) coupled with population balance model (PBM) in the Lightnin static mixer (LSM). Different breakup and coalescence kernels were used to study the effect of Reynolds number (Re), gas volume fraction (α_d) and the element numbers on the bubble dispersion behavior and mixing efficiency. Bubble breakup capacity and mass transfer rate were quantized via gas-liquid interfacial area and volumetric mass transfer coefficient (k_La) in LSM and Kenics static mixer (KSM). The distributive mixing performance and dispersive mixing performance of LSM and KSM were analyzed based on CoV and fluid microelement stretching rate. The results showed that Luo coalescence model and Prince model overestimated the bubbles coalescence efficiency in LSM, and the bubble size calculated by the Luo-Turbulent model was in good agreement with the experimental data. With the increase of Re and α_d, the dispersion behavior of bubbles in LSM was further strengthened. Increasing the number of elements could significantly improve the gas-liquid mass transfer efficiency at higher Re condition. CoV curve showed that LSM had better distributive mixing performance than KSM, and three LSM elements could make the mixedness more than 95%. The dispersive mixing efficiency of LSM was 1.06 to 1.16 times that of KSM. The critical superficial velocities of flow pattern transition from pseudo-homogeneous to heterogeneous were identified based on pressure fluctuation signal time series in the LSM.

Microchemical technology is becoming an important method to strengthen the flow chemistry. In view of the limitations of the preesterification process of free fatty acids, such as low mass transfer efficiency, bulk volume, and high energy consumption. A twist plug-in microchannel was proposed to solve the above mentioned problems in the conventional esterification reactor. Methanol and oleic acid were employed as experimental systems to investigate the influence of parameters such as flow rate, reaction temperature and channel length on the preesterification reaction, and compared with other esterification reactors. The results showed that the conversion rate in the twist plug-in microchannel could reach 94.3% with only 3.26s at 40℃. With the increase of flow rate in the twist plug-in microchannel, the conversion first decreased and then increased, and the yield of fatty acid methyl ester gradually increased. The increase of catalyst dosage and alkyd molar ratio could promote the preesterification reaction. Increasing the reaction temperature and increasing the length of the twist plug-in microchannel could promote the conversion rate and the yield of fatty acid methyl ester. The correlation equations of reaction conversion rate and yield of fatty acid methyl ester were established, respectively. The calculated data were in good agreement with the experimental values with the relative error within 15%.

Existing hydraulic transmission media of water, oil and other anhydrously synthesized materials have problems such as poor stability at high temperature and large temperature-dependent viscosity change. In contrast, In-Bi-Sn alloy has low melting point, good fluidity, and stable high-temperature properties, making it an ideal base fluid for hydraulic transmission media at extreme high temperature. In this work, In-Bi-Sn-based Si₃N₄/GNFs hybrid nano-fluids with volume fractions of 0, 5%, 10%, 20% and 30% were prepared by a two-step method. The morphology, dispersion, and thermal stability of the samples were characterized by TEM, SEM+EDS and TGA. The rheological properties and lubricity of the samples were studied by high-temperature rotary rheometer and friction wear testing machine. The differences in thermal stability, rheology, and lubricity between samples and existing high-temperature hydraulic media were compared. The results showed that Si₃N₄ was embedded in GNFs plates and dispersed in In-Bi-Sn matrix in the form of aggregates, and the aggregate size of 10% sample was smaller than that of 20% sample. The viscosity of the samples increased with the increase of the volume fraction of the hybrid nanoparticles, and the effects of the static time of the liquid and the number of phase transformation on the viscosity of the sample <30% were not obvious. Under the influence of Brownian motion of nanoparticles, the higher the volume fraction of nanoparticles was, the more significant its temperature-dependent viscosity change was. The 20% sample showed obvious thinning characteristics, due to the change of particle size. Adding Si₃N₄/GNFs hybrid nanoparticles could significantly improve the lubrication characteristics. Compared with the existing high-temperature hydraulic medium, the In-Bi-Sn-based Si₃N₄/GNFs hybrid nanofluid had excellent thermal stability, less temperature dependence in viscosity and good high-temperature lubrication.

To improve the heat exchange effect of the semicircular spiral channel outside the tubular reactor, a jet inlet was set on the wall of the traditional spiral channel. Three kinds of nanofluids (CuO-H₂O, Al₂O₃-H₂O and TiO₂-H₂O) were used as heat transfer fluids, respectively. Based on Mixture mixing model, the influence of different nanofluids on the heat exchange and flow characteristics of the semi-circular spiral channel at different Re(10000—36000) and jet velocity ratios was investigated. The heat transfer enhancement factors PEC_j0 and PEC_j were used to evaluate the comprehensive heat transfer enhancement before and after increasing the jet flow in the semi-circular spiral channel. The results showed that at the jet speed ratio ε=0—5, the pressure drop of Al₂O₃-H₂O nanofluids was highest, while that of CuO-H₂O nanofluids was lowest. Al₂O₃-H₂O nanofluids exhibited the best heat transfer performance at ε=0, with the average Nu number 1.31 times that of H₂O. Compared to ε=0, the average Nu_m of the spiral channel increased by 52.01% at ε=1—5. With the increased jet velocity ratio, the higher the turbulent kinetic energy, the better the mixing effect between jet fluid and main stream fluid. The influence range of jet fluid at each velocity ratio was 0°≤θ_j≤50°. When ε=3, the spiral channel generates three vortex structures. PEC_j0 increased first and then decreased with the rising Re, reaching its maximum value at Re=20173, while PEC_j increased with the rising jet velocity ratio. Overall, the heat transfer enhancement effect of jet impinging on Al₂O₃-H₂O nanofluids in spiral channels was the best in this study.

To address the problems of intensive water consumption and high production of ammonia-containing wastewater in the defluorination washing process of niobium hydroxide powders, a ceramic membrane-based technology and process for niobium hydroxide powder washing was developed. The effects of membrane pore size, washing sequence and washing liquid usage on the removal of F^- impurities from niobium hydroxide slurry were investigated. The final product purity and economic efficiency were compared between the ceramic membrane-based and the traditional pressure filter-based methods. The results showed that constant volume diafiltration washing was the best way for removing F^- in niobium hydroxide slurry. When the ratio of material to washing liquid was 1∶60kg/L, the F^- content in normal niobium hydroxide slurry reached the standard by using the α-Al₂O₃ ceramic membrane with a pore size of 200nm. The α-Al₂O₃ ceramic membrane with a pore size of 50nm could efficiently wash the ultra-fine niobium hydroxide powder. Both ceramic membranes indicated good stability in the application of niobium hydroxide powder washing. The ceramic membrane-based washing method showed excellent purification effect on niobium hydroxide as well as the final product Nb₂O₅. The method was obviously better than the pressure filter-based method in terms of removal impurities and saving operation cost. Therefore, the ceramic membrane-based washing process offered high technical and economic feasibility for promoting the green development of tantalum-niobium hydrometallurgy.

Ammonia has a better future market as a carrier of hydrogen energy and renewable energy for its high energy density and carbon-free characteristic. Ammonia is easier to store and transport than hydrogen and is intrinsically safe. It is expected to become one of the carbon-free energy development routes to promote industrial reform, social progress and national development. From the perspective of the whole industrial chain of ammonia energy, the development trend of synthetic ammonia industry, and the latest progress and cost economy of various synthetic ammonia technologies are introduced; the main storage and transportation methods, efficiency, cost and safety characteristics of ammonia are listed; the new energy fuel applications of ammonia, including ammonia fuel cell, ammonia internal combustion engine and ammonia gas turbine, the development status of the technologies and the fuel cost economy, as well as the hydrogen production efficiency and production cost advantages of ammonia decomposition are reviewed. Through the above technical and economic analysis, the importance of ammonia energy in the energy system is discussed, the development direction of ammonia energy technology is further sorted out.

Under the goal of "peak carbon dioxide emissions, carbon neutral", green hydrogen has become a promising clean energy source. The technology of producing green hydrogen by alkaline electrolysis of water has the highest degree of commercialization, but because of the slow kinetic process of oxygen evolution reaction (OER) and the high overpotential, it has become the main bottleneck restricting the efficiency of electrolytic water electrode. There is still much room to improve the OER performance of nickel mesh or nickel foam electrode widely used in commercial electrolytic cells. It is beneficial to improve the electrode efficiency and reduce the cost of hydrogen production by compounding nickel-based catalytic functional layer on it and developing new high-activity oxygen evolution electrode. Electrodeposition technology has the advantages of simple process and mild conditions, which is beneficial to scale up the production of self-supporting electrodes, and has become one of the ideal processes for industrial production of OER electrodes. In this paper, the research progress of nickel-based oxygen evolution electrode prepared by electrodeposition technology and used in alkaline electrolysis of water in recent years is reviewed. Nickel-based (hydrogen) oxides, bimetals, multi-metals and nonmetal-doped nickel-based catalysts are prepared on nickel mesh or nickel foam substrate by electrodeposition technology as catalytic functional layers. The OER performance of nickel-based self-supporting electrodes is improved by enhancing the conductivity of catalytic functional layers and the synergistic effect between metals, increasing the number of active sites, reducing the diffusion path and changing the surface atomic configuration. In addition, the application of nickel-based self-supporting electrode in water electrolysis field is clarified, and the challenges of electrodeposition method are pointed out.

With the development of gas hydrate exploitation in the deep sea, there is an urgent need to solve basic problems, such as the reformation of hydrate and sand production in the wellbore. At present, there are few research reports on the reformation of hydrate in a stirred system containing fine-grain sands. By selecting fine-grain sand with size of 3.7—10.3μm, changing the sand concentration (0.6%, 1.6% and 5.0%), salt concentration (0.1%, 0.6% and 1.0%) and sand salt ratio, the influence of sand and salt on the secondary formation kinetics of methane clathrate under high pressure (8MPa) was studied. The results show that: ① compared to the primary induction period, the shortened time of the secondary induction period increased with the decrease of sand particle size within the range of 3.7—10.3μm; ② The fine-grain sand at concentrations of 0.6% and 1.6% promoted the secondary nucleation of hydrates; ③ In the range of 0.1% to 1.0% salt concentration, the higher the salt concentration, the closer the final gas consumption and maximum gas consumption rate of the primary and secondary generation of hydrates were, and the more significant the inhibitory effect of salt on the "memory effect" of hydrates was; ④ Under the conditions of low (0.6%∶0.1%), medium (1.6%∶0.6%), and high (5.0%∶1.0%) salt sand concentration ratios, as the sand salt ratio increased, the induction period for primary hydrate formation shortened, and the induction period for secondary hydrate formation increased. All systems had shorter induction periods for secondary formation than the induction period for primary formation, and as the ratio increased, the difference between the two induction periods decreased. It was concluded that sand particles could promote reformation kinetics in the stirring system, while salt would inhibit reformation kinetics. However, the effect of the concentration proportion of fine-grain sand and salt on the kinetics of secondary hydrate formation depended on the concentration.

The mildly-expanded coal-based graphite was prepared from coal-based graphite via liquid oxidation-thermal reduction process using concentrated H₂SO₄ as intercalator and KMnO₄ as oxidant. The microstructures of mildly-expanded coal-based graphite were characterized by XRD、SEM、TEM、Raman、nitrogen adsorption-desorption and XPS, and their lithium ions storage performance and the effect of the degree of mildly-expanded modification on their structure were further investigated. The results demonstrated that the mildly-expanded modification not only could expand the interlayer spacing of graphite crystallites, decrease the crystallite size and increase the content of nanopores, but also could introduce oxygen-containing functional groups such as carbonyl, hydroxyl and alkoxy groups into coal-based graphite. When the amount of oxidant is 0.30 times that of coal-based graphite, the interlayer distance of the mildly-expanded coal-based graphite was 0.3374nm, and its nanopore channels mainly consisted of 1—2nm micropores and 2—6nm mesopores with a specific surface area of 24.6m²/g and was rich in oxygen-containing functional groups such as C\stackrel{}{̿}O, C—O—H and C—O—C. Mildly-expanded coal-based graphite as anode for lithium-ion batteries exhibited excellent electrochemical performance, in which the reversible specific capacity could reach up to 511.1mAh/g at 0.1C and 348.7mAh/g at high current density of 5C, and the specific capacity at 5C could still be maintained at 313.3mAh/g after 300 cycles with a capacity retention rate of 89.9%. Its comprehensive performance was much higher than that of coal-based graphite. The excellent electrochemical energy storage properties of mildly-expanded coal-based graphite were closely related to its microstructure, which is rich in graphite microcrystal layers, nanopores and oxygen-containing functional groups.

The volatile organic compounds (VOCs) in oil depot exhaust should be removed and recycled. The present authors simulated the cryogenic condensation removal of the small quantity of propane in the mixture gas using the one-dimensional calculation method. The results showed that for gas with initial propane fraction of 2.25% the heat exchanger used in present study with a length of 2.85m was required to reduce propane molar concentration in the mixture gas to 1.26×10^-4, and the molar fraction of propane decreased by 76% in the first one meter of the heat exchanger while by only 23.6% in the next 1.85m. The length of the heat exchanger required for condensation varied with the initial concentration of propane. The shortest length, 2.84m, was required when the initial molar concentration of propane was 2.0% . When the initial molar concentration of propane was below 2.0%, the main factor affecting the removal of propane was the condensation rate, and the required heat exchanger length increased rapidly in an approximately parabolic trend as the propane initial molar concentration decreased. When the propane initial molar concentration was higher than 2.0%, the main factor affecting the removal of propane became the total quantity of propane, and the required heat exchanger length increased approximately linearly at a smaller rate as the propane concentration increased. Present study could provide a reference to the design of the length of the heat exchanger for the condensation removal of the valuable component in petroleum gas.

In order to fully utilize the advantages of active and passive heat dissipation in the battery heat dissipation system of liquid cooled composite phase change materials, a simulation model of the composite heat dissipation system was established, and the synergistic idea between different heat dissipation modules in the composite system was proposed. Based on this idea, the optimal values of the filling amount, liquid cooling start time, and coolant flow rate of the composite phase change material (CPCM) in the system were explored. The results indicated that the synergy between CPCM filling amount, liquid cooling start time, and coolant flow rate had a significant impact on whether the composite system could fully utilize the active and passive heat dissipation advantages of each module. When the battery spacing reached 2mm, the filling amount of CPCM could meet the heat dissipation requirements of the battery at low magnification. Turning on the liquid cooling module when the liquid fraction of CPCM was 0.9 could significantly improve the utilization rate of CPCM module. When the coolant flow rate was greater than 0.03m/s, the temperature rise of the battery could be suppressed. When the flow rate was greater than 0.2m/s, the latent heat of CPCM could be recovered. Choosing the corresponding speed according to the different needs of the car could achieve the goal of reducing energy consumption. This article proposed a collaborative approach that could provide a new approach for the research of composite heat dissipation systems.

Under the background of Carbon Peak and Carbon Neutralization, the demand for pollution and carbon reduction of coal-fired units is urgent. Co-fired coupled directly with renewable fuel for power generation can not only reduce carbon emissions, but also significantly improve energy utilization level. However, the characteristics of different fuels lead to complex flue gas characteristics after co-combustion, which poses new challenges to SCR catalysts. The article briefly reviews the reaction mechanism of the SCR catalysts, comprehensively elucidates the influence of boiler flue gas after burning co-fired renewable fuels on the catalytic process of SCR catalyst, and discusses in detail the effects of different poisons on the catalytic activity of SCR catalysts. Then, various anti-poisoning strategies for catalyst design are proposed based on different anti-poisoning researches. This paper also expounds the development trend of anti-poisoning catalysts in the future. To achieve low-carbon economic development of thermal power units, it is necessary to clarify the poisoning effect of co-combustion conditions on catalysts, enhance the adaptability of multi-co-combustion scenarios, and improve the yield and quality of industrial products through process improvement.

The development of biodiesel is of great scientific significance for achieving carbon emission reduction and energy substitution. The high-value green conversion of biodiesel by-product glycerol are conducive to the development and extension of the biodiesel industry chain. 1,3-Propanediol produced by catalytic hydrogenation of glycerol has become a research hotspot, and the design of catalysts with high activity and selectivity is the key. The dehydration-hydrogenation mechanism, direct hydrogenation mechanism and redox mechanism of glycerol to 1,3-propanediol on Pt-WO _x supported catalysts are elaborated. Pt dispersion, WO _x state and Pt-WO _x interface contact behavior in Pt-WO _x catalysts are further analyzed as they are the main influence factors on the catalytic performance. Pt dispersion affects the activation of H₂ and the further hydrogenation of intermediates. The WO _x state not only promotes the dispersion of Pt, but also closely relates with the Brönsted acid site of the catalyst. The Pt-WO _x interface affects the hydrogen overflow on the catalyst surfaces and the in-situ formation of the Brönsted acid site. Finally, it is proposed that Pt-WO _x catalysts should be rational designed from these three aspects, and the influence of each component and their interactions on the direct catalytic hydrogenation of glycerol should be deeply explored. Reaction mechanism and the influence of the different hydrogenation mode on the selective hydrogenation of glycerol should be investigated in order to promote the large-scale development and application of the hydrogenation of glycerol to 1,3-propanediol.

Hydrogenated petroleum resins have wide application in high-end fields, and the demand for high-quality petroleum resins has increased year by year. Efficient production of high-quality hydrogenated petroleum resin has become the research focus in the field. High-quality petroleum resin is mainly produced by hydrogenation of raw resin materials and efficient and stable hydrogenation catalysts are the key. However, the resin hydrogenation system still suffers from problems such as poor hydrogenation performance, low diffusion of resin in catalyst pores and harsh reaction conditions. This review summaries the research progress in terms of rational design of active components, geometric and electronic structure, support morphology and pore structure. Highlighting the effect of the dispersion of metal active sites, active sites distribution, valence states engineering together with synergy between composite metal are the key factors to regulate the performance of catalyst. At the same time, the problems such as the reaction mechanism, the deactivation and regeneration mechanism of active sites and the development trend of hydrogenation catalysts in the future were summarized.

As an important secondary energy, hydrogen is of high energy density, environmental friendliness and wide use, which is an important direction of human strategic energy development. However, hydrogen storage and transportation are still facing problems of high cost and safety. The hydrogen storage and release technology based on liquid organic hydrogen carriers (LOHCs) has become one of the available technologies with its advantages of relatively high hydrogen storage density, mild storage conditions and convenient transportation. Compared with polycyclic aromatic hydrocarbons, nitrogen-containing LOHCs is milder in catalytic hydrogenation and dehydrogenation, which can effectively improve the robustness of hydrogen storage and release and the reaction efficiency. Based on this, this paper systematically reviewed the progress in hydrogenation and dehydrogenation of nitrogen-containing LOHCs, and revealed the reaction pathway and catalytic mechanism of these two kinds of reactions. Then, the hydrogenation/ dehydrogenation catalysts were systematically summarized from the aspects of active center, support, bimetallic synergistic effect, reaction conditions, catalyst stability, etc. After that, the reaction kinetics models based on the series reactions and reaction network were analyzed in detail. At last, the current challenges of nitrogen-containing LOHCs were introduced, as well as the perspectives of LOHCs systems. However, there are still many problems for this technology, and further in-depth research should be conducted in the aspects of formulation system of organic hydrogen carriers, continuous hydrogen storage and release reaction system, catalyst design and preparation, structure-activity relationship of catalysts, precise reaction kinetics, and comprehensive physicochemical properties database.

The development of cost-effective and efficient electrocatalysts for hydrogen evolution reaction (HER) is one of the key factors to meet the industrial-scale application demand. Herein, heterostructure Co/NiCoP nanoparticles grown on carbon cloth were successfully fabricated via low temperature electrochemical deposition method, and characterized and theoretically calculated. Moreover, the HER performance of the obtained samples were investigated in 1mol/L NaOH alkaline electrolyte with a three-electrode electrochemical workstation. The heterostructure Co/NiCoP composite showed excellent catalytic performance, with a low overpotential of 54mV at a current density of 10mA/cm² and Tafel slope of 78.5mV/dec. Based on the theoretical calculations and characterized results, the high electrocatalytic activity of Co/NiCoP was attributed to the following three points: ① The well dispersed Co/NiCoP nanoparticles on carbon cloth increased the exposure of surface active sites; ② The electron interaction between Co and NiCoP was promoted via heterostructure, which accelerated the charge transfer rate and increased the conductivity of the material; ③ The construction of Co/NiCoP heterostructure boosted the alkaline HER kinetics by accelerating the water dissociation step. Therefore, the construction of Co/NiCoP nano-heterogeneous catalysts has enriched the applications of non-noble metal based electrocatalysts in electrolysis of water.

Selective catalytic reduction (SCR) can effectively remove pollutant NO _x from flue gas, but it also catalyzes the generation of SO₃, endangering equipment safety and atmospheric environment. In this study, the effects of temperature, flue gas atmosphere and catalyst components on the catalytic production of SO₃ by SCR catalyst were investigated on a simulated SCR equipment. The changes of the catalyst before and after reaction were analyzed by X-ray fluorescence spectroscopy (XRF) and X-ray photoelectron spectroscopy (XPS). The results showed that the yield of SO₃ increased with temperature and O₂ content could affect the SO₃ production, but the effect was minimal with O₂ content over 2%. Increasing SO₂ concentration decreased SO₃ production rate, but total SO₃ amounts still increased. At a certain concentration of NH₃, the formation of SO₃ was significantly inhibited, and a large amount of sulfur and ammonium salt deposition was produced. However, the oxidizing gas NO₂ in NO _x could increase the proportion of V⁵⁺ in the catalyst and promote the formation of SO₃. In the actual reaction process, denitrification competes with SO₂ oxidation. Reducing the NO₂ concentration in flue gas could improve the denitrification efficiency and reduce the generation of SO₃. The vanadium and titanium in the catalyst could increase the formation rate of SO₃, while the silicon could inhibit the formation of SO₃. This study provides a theoretical basis and reference for the operation optimization of actual SCR.

The Z-scheme CuBi₂O₄/BiOBr (CBOB) heterojunction was prepared by a solvothermal method and compounded with graphene hydrogel (GH) to obtain CuBi₂O₄/BiOBr@GH (CBOBG). The crystal structure, surface composition, microstructure, specific surface area and photoelectric properties of the photocatalyst were characterized by XRD, XPS, SEM, TEM, N₂ adsorption-desorption, UV-vis DRS, PL spectra and electrochemistry. The photocatalytic activity of CBOBG was further studied by the tetracycline degradation coupled reduction of Cr(‍Ⅵ) under visible light. The results showed that the degradation rate of tetracycline and the reduction rate of Cr(‍Ⅵ) of CBOBG reached 86.1% and 100% respectively within 120min. The main active substances in the degradation process were superoxide radical and hole, while those in the reduction process were electron.

Using urea and L-glutamine (Lg) as precursor materials, Lg molecules were successfully linked to the edge of carbon nitride (CN) by freezing-calcination method, and Lg grafted porous carbon nitride (LCN) photocatalysts with excellent photocatalytic performance were prepared. The morphological structure and photocatalytic performance of the samples were tested by X-ray spectroscopy (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The results showed that the introduction of Lg molecular chains could not only increase the specific surface area of the material and provide more active sites, but also effectively promote the rapid separation and transfer of photogenerated electrons, resulting in excellent photocatalytic activity. Under visible light irradiation, the hydrogen formation rate of LCN-10 photocatalyst with the optimal mass ratio during hydrogen evolution test was up to 658µmol/(g·h), about 3 times higher than that of pure phase CN. LCN-10 also indicated good catalytic activity in photodegradation tests of tetracycline hydrochloride (TCH) and levofloxacin (LEV), achieving 98% as well as 85% photodegradation of TCH and LEV within 60min. This work provided a new perspective on the surface modification and performance optimization of CN-based photocatalytic materials.

Phase change materials(PCMs) play a vital role in promoting the development of new energy sources and improving energy utilization. However, the defects of single organic phase change materials such as easy leakage, low thermal conductivity and weak light absorption hinder its wider application and develop. In order to solve these bottleneck problems and improve the utilization efficiency of thermal energy, carbon materials with excellent properties are used as carrier materials to encapsulate phase change materials to construct composite phase change materials with stable shape and enhanced thermal performance. This paper discusses the enhanced heat transfer mechanism of carbon materials based on relevant theories, focused on the research progress and challenges of organic phase change materials in different types of carbon-based materials, and introduced the application of carbon-based composite phase change materials in recent years in thermal management, energy conversion and storage, smart wearable textiles and infrared responsive materials. Finally, based on the combination of theory, numerical, simulation and experimental methods, the future research directions and advanced multifunctional applications of carbon-based composite phase change materials in thermal energy storage, transfer and conversion are prospected.

Silicon carbide ceramic membranes have the advantages of high-temperature resistance, thermal shock resistance, corrosion resistance, high flux, long service life and so on, which are key materials in the field of environmental pollution control. How to prepare high-performance silicon carbide ceramic membranes for application-oriented processes has become a current research hot spot. In this review, the forming methods of silicon carbide ceramic membranes are introduced, including dip-coating method, spraying method, chemical vapor deposition method and phase inversion method. In addition, the molding mechanism, influencing factors, advantages and disadvantages of each method are elucidated. The mechanism, characteristics and research status of silicon carbide membranes sintering technology are summarized, including recrystallization technology, precursor conversion technology, in-situ reaction sintering technology and new sintering technology with emphasis on the practical application value and challenges of co-sintering technology. It is beneficial to clarify the relationship between the properties of silicon carbide ceramic membranes and the preparation process. The application status and prospect of silicon carbide ceramic membranes in high temperature flue gas purification, oil-water separation and gas separation are expounded. Finally, the industrial application potential of silicon carbide ceramic membranes is prospected.

Flame synthesis of carbon nanotubes (CNTs) and related composites possesses the merits of continuous operation with low-cost, which shows great potential for practical application. However, the physical and chemical environments of flame are complex. Therefore, the as-obtained product exhibits unmanageable structure and composition. In this work, the basic configuration of premixed flame and diffusion is firstly presented. On this basis, the features of flame synthesis in terms of fuel type, catalyst and characteristics of CNTs are summarized. Secondly, the general growth mechanism of CNTs in flame environment is introduced. Furthermore, specific growth models of CNTs in flame environment, including tip growth mode, base growth mode, interacting particle model and reasonable growth mode for branch, welded, and spiral structures are discussed. Finally, practical application of flame synthesized CNTs based composites in areas of energy storage, catalyst and so forth, are summarized. However, the drawbacks, such as poor controllability of flame process and complex product composition are still existed, which is unfavorable for performance regulation. In future, continuous optimization of flame process is needed. Adopting hybrid preparation process or constructing segmental burner configuration will play a positive role in improving process controllability and finally realizing the refinement regulation of product.

The composite material with three-dimensional (3D) packing network has excellent thermal conductivity, which is one of the ideal materials to solve the problem of heat dissipation of electronic devices and is widely used in the field of thermal insulation materials. This paper described the important research progress of 3D thermal insulating polymer materials at home and abroad in recent years. Firstly, starting from the preparation method of 3D filler structure, it introduced the main ways to prepare 3D thermal insulating composite materials, including template method, foam method, 3D printing method, composite particle method and polymer frame method, and analyzed the forming mechanism of different construction methods. The advantages and disadvantages of each preparation method were introduced. Secondly, the finite element simulation of 3D heat conduction network was summarized, and the heat conduction models commonly used at present were analyzed. Finally, the bottleneck and future development direction in the preparation of thermal insulating composite materials with 3D network structure were described, including the elaboration and free construction of 3D filler network, the treatment of the interface thermal resistance between 3D filler structure and polymer, the establishment of a general heat conduction model of 3D filler network and the reduction of process difficulty. It provided the direction and idea for the research and application of high thermal conductivity insulating composites.

Polymer functionally gradient materials (PGMs) are heterogeneous polymer-based composites, where their compositions or structures change continuously in one or multi-spatial directions. Traditional methods for preparing PGMs suffer from complexity, customization difficulties, and poor universality. This article introduced the advantages of additive manufacturing(AM) based on the "discrete-stacking" principle and summarized the fundamental principles, material characteristics and properties of PGM formation using AM techniques, including fused deposition molding, direct ink writing, vat photopolymerization, materials jetting and selective laser sintering. Although preparing PGMs using AM posed challenges such as the lack of design criteria, characterization methods and systematic research methods, AM would become an excellent method for PGM preparation with the deepening of basic scientific research on new AM materials and the continuous development of specific applications for service conditions and process performance.

Dyes have aroused great research interest in the photocuring field due to their excellent photochemical and photophysical properties. The introduction of dyes into traditional photoinitiating systems can not only improve the visible-light absorption abilities for the systems, but also effectively facilitate the rate of photoinitiated polymerization. The dye-based multi-functional photoinitiating systems can successfully initiate many free radical polymerizations of acrylates and cationic polymerizations of epoxides under visible-light source, and they also show a broad application prospect in the fields of efficient preparation of materials and photocuring 3D printing. Based on these, this literature summarized the working mechanisms of dyes serving as photosensitizers, and reviewed the research progress of the different types of dyes in visible-light initiating systems in recent years. Furthermore, the future development of visible light day-based photosensitizers in this direction were prospected. Also, the importance of introducing dyes into visible light initiation system was emphasized directly, aiming at promoting the development of material preparation towards a more energy saving and environment protection direction, and providing new ideas for the future design and development of visible-light initiating systems.

Hierarchically porous aluminosilicate nanospheres (NKM-5-Al-x) with different Si/Al ratios were synthesized by employing organic mesomorphous complexes of cationic surfactant cetyltrimethylammonium bromide (CTAB) and anionic polyelectrolyte polyacrylic acid (PAA) as the dynamic template and aluminum isopropoxide as the aluminum source. The hierarchically porous aluminosilicate nanospheres were characterized by X-ray diffraction (XRD), nitrogen adsorption desorption, temperature programmed (NH₃-TPD), nuclear magnetic resonance (²⁷Al NMR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The SBA-15 and MCM-41 silica materials with relatively uniform pore structure were compared. The effects of the hierarchically porous structure and acid properties of the materials on the adsorption and separation performance of polycyclic aromatic hydrocarbons (PAHs) were investigated. The results showed that the pore distribution and acid properties had a significant impact on the separation performance of PAHs. The hierarchically porous structure was profit for the diffusion of PAHs. The increase of acid content was beneficial to improve the separation efficiency of PAHs. NKM-5-Al-5 with strong acid content and hierarchically porous structure indicated the best PAHs separation effect. The separation degree of R_{PAHs/non-aromatics} was above 1.2 and the desorption/adsorption rate was fast with the desorption/adsorption rate ratio close to 1.

Metal organic frameworks (MOFs) as one of new porous materials, have promising application in drying field. In this study, a rapid microwave synthesis of MOF-808 at 140℃ and 12.83mol/L formic acid concentration was reported. The obtained MOF-808 was thoroughly characterized by X-ray diffractometer, field emission scanning electron microscope and physical adsorption instrument. The water vapor adsorption capacity of MOF-808 increased with increasing formic acid concentration (0.521g/g to 0.810g/g), decreased with the increase of adsorption temperature, and the optimal adsorption working conditions were 30℃ and 90% relative humidity. MOF-808 showed a higher rate of adsorption at high humidity. The average water vapor adsorption capacity of MOF-808 was 0.529g/g with standard deviation 0.018 under the conditions of various CO₂ concentrations, which indicated that MOF-808 had a good adsorption selectivity for water vapor. The variation of CO₂ concentration did not affect its water vapor uptake performance. The regeneration efficiency of MOF-808 was higher than 90% after eight cycles at lower temperature (70℃), which indicated that MOF-808 had a great energy conservation potential and much better cycle stability.

Phthalate plasticizers (PAEs) are wildly used in the plastic production, which may bring a risk of leakage in the food industries as packaging materials. Herein, to detect residual plasticizers in food such as edible oil, a specific electrochemical sensor was developed by the molecular imprinted polymer (MIP) approach. One of the PAE molecules of diisononyl phthalate (DINP) was selected as the target molecule and the MIP was optimized and obtained by a one-pot radical polymerization. The DINP adsorption isotherms conformed to the Langmuir model, and the saturated adsorption capacity was calculated as high as 8.61mg/g, more than twice that of non-imprinted polymer (NIP). The DINP-MIP was modified on the surface of a screen-printed electrode to obtain a DINP-MIP/SPE electrochemical sensor. In the detection range of 0.05×10^-6—0.7×10^-6mol/L, the standard working curve of simulated oil had excellent linearity, and the limitation of detection (LOD) of DINP could reach 0.117mg/kg. In the detection of edible oil, the blank spiked recoveries were 104.9%—106.6%, indicating its promising practical applications in the rapid detection of plasticizers.

Polyimide (PI) is a highly stable class of polymeric materials widely used in gas separation applications. However, research on new organic fillers for PI is limited with few reports on their application in total heat exchange and fresh air systems. In this study, the flower-like PI microspheres with a lamellar structure were synthesized using 1,4-phenylenediamine (pPDA) and benzophenone-3,3′,4,4′-tetracarboxylic dianhydride (BTDA) as monomers via a solvothermal process polymerization. By introducing PI microspheres into the polyamide (PA) separation layer via interfacial polymerization (IP), a series of PI-PA composite total heat exchange membranes were successfully fabricated. The effects of the addition method and amount of PI microspheres on membrane morphology, water contact angle, surface roughness, CO₂ and water vapor permeability, and total heat exchange efficiency were thoroughly investigated. The homogeneous dispersion of PI microspheres in trimesoyl chloride (TMC) oil phase ensured simultaneous PI loading and interfacial polymerization, effectively avoiding particle stacking and interfacial defects. The optimized PI-PA-Ⅳ-2 composite film demonstrated outstanding moisture permeability and gas resistance with CO₂ permeability decreasing from 21.04GPU to 3.64GPU and water vapor permeability increasing from 1763.45g/(m²·24h) to 1949.51g/(m²·24h). Moreover, this membrane exhibited comparable heat exchange efficiency (97.47%) and enthalpy exchange efficiency (71.41%) to commercial paper membranes, highlighting its potential as a valuable approach for the high-efficiency total heat exchange membranes.

To solve the problem of oil contamination in water bodies, a superhydrophobic oil-water separation bionanomaterial was prepared by assembling nano-silver films on the surface of cotton fabric using a simple gas phase adsorption method and modified by octadecyl thiol. The surface microstructure, nano-silver film loading and hydrophobic properties were characterized by scanning electron microscopy and contact angle determination. The results showed that the modified cotton fabric surface exhibited good hydrophobic and lipophilic properties due to its irregular microstructure similar to a lotus leaf surface with a contact angle of 164.4° for water droplets and an approximate contact angle of 0° for oil droplets. The results of the oil-water separation experiments and stability tests also indicated that the separation efficiency of the prepared bionic superhydrophobic cotton fabric for different types of oil-water mixtures was stable at over 90% after 10cycles of separation experiments. Meanwhile, the superhydrophobic properties of the prepared superhydrophobic cotton fabric did not change significantly after immersion in different corrosive solutions (acid, alkali, sodium chloride, boiling water) and abrasion by sandpaper, indicating that the material had good durability, indicating that the material had good durability and stability. This study was expected to provide a reference for the preparation of oil separation materials.

Soil contamination is often caused by the inappropriate treatment of industrial wastes and municipal sewage threatening the safety of environment, food and ecology as well as the sustainability of society. Bioremediation refers to the application of microorganisms to dissociate organic compounds, detoxifying heavy metal ions or reducing their bioavailability. The advancement of biotechnology has empowered technical innovation of bioremediation methods and their applications in the treatment of contaminated farmland and wasted plant site. This review starts with a brief introduction to bioremediation techniques and their applications to three major types of soil contaminants. The applicability of these methods was discussed from the viewpoint of contaminates transformation and utilization. The technical advancement in the selection and screening of degradation microorganisms, molecular biology methods for assessing microbiological ecology as well as novel bioaugmentation principles were detailed. The applications of bioremediation techniques in the treatment of gas stations, abandoned plants and straw mulching were described. The problems in the development of soil bioremediation techniques such as the assessment of soil remediation outcome, formation of high performance degrading microbial consortia were outlined, as well as the prospects of soil remediation techniques.

In order to ensure national energy security and reduce our dependence on foreign oil and gas resources, it is necessary to enhance the exploration of domestic natural gas and other resources. During the exploitation and purification of natural gas, acid gas H₂S and CO₂ are often produced. Existing acid gas treatment technologies mainly recover the sulfur in H₂S through the Claus process, which leaves CO₂ untreated and results in the waste of hydrogen and serious carbon emissions. If H₂S and CO₂ can be synergistically converted, it is expected to reduce carbon emissions and obtain high-value chemicals such as hydrogen, syngas and sulfur simultaneously. Based on the experimental and theoretical researches of more than 30 years in related fields worldwide, this paper reviews the development history of synergistic conversion of H₂S and CO₂, and summarizes the relevant research progress from the perspectives of thermal reaction (direct thermal reaction, process flow and economic evaluation, catalytic thermal decomposition), photocatalysis, electrocatalysis and plasma catalysis. Detailed information on catalysts, reaction conditions and distribution of reaction products is presented, and the advantages and disadvantages of various technologies are compared. The development trend of the synergistic conversion of H₂S and CO₂ is prospected and the use of green electricity for small-scale application of electrocatalysis technology in the near future is suggested. At the same time, it is feasible to reduce the carbon emission of thermal catalytic technology through solar heat storage and improve the photocatalytic efficiency through concentration of solar energy. In addition, it is necessary to consider the characteristics of acid gas reservoirs in future studies, including the influence of different H₂S/CO₂ ratios and impurities such as H₂O on the reaction process.

Metal-organic framework materials have the advantages of larger specific surface area, tunable pore and topological structures, and abundant active functional groups compared with traditional adsorbent materials, which can be used as high-performance adsorbents for the removal of heavy metal pollutants from water. In this paper, the structural characteristics of MOFs as adsorbents for water treatment were introduced. The regulatory strategies of MOFs based on metal node doping, side group functionalization and post-synthetic modification, such as porosity, surface activity, framework flexibility, water stability, scalability, biotoxicity and recyclability, were emphatically analyzed. Then, the research progress of MOFs in the removal of heavy metal ions was introduced, mainly on cationic heavy metal ions such as Pb(Ⅱ) and Hg(‍Ⅱ), and anionic oxyanions such as Cr(Ⅵ) and As(Ⅲ)/As(Ⅴ) in water, and the mechanism of the action of MOFs in the removal of heavy metal ions in water was elaborated. Finally, the research directions of improving the water stability and adsorption performance of MOFs, balancing the relationship between the structural characteristics of MOFs, studying the migration and enrichment of MOFs in nature, and the controllable preparation of MOFs with low cost and high benefit were put forward for improving the reference of MOFs in the field of high-performance adsorption.

Anaerobic digestion is a sustainable technology for organic waste treatment and disposal, which can produce renewable energy biogas while degrading organic waste. It is an environmentally friendly treatment technology. However, the substrate in anaerobic digestion system has complex rheological characteristics, and its high viscosity and poor flowability hinder the stable operation of the reaction. Therefore, research on flow field characteristics of anaerobic digestion can contribute to the understanding in internal flow pattern of anaerobic digestion system and improve the operating results and process stability. The characteristics of the substrate in anaerobic digestion and applicable rheological models are analyzed, and current status of the rheological model selection in numerical computational fluid dynamics (CFD) simulation process as well as application of particle image velocimetry (PIV) and positron emission particle tracking (PEPT) techniques are summarized. To obtain reliable flow field visualization results, it is necessary to pay attention to other rheological properties such as viscoelasticity and thixotropy while considering the shear-thinning properties of anaerobic digestion matrices. In future research, multiple flow field visualization techniques should be used in combination to optimize the hydrodynamic properties of anaerobic digestion.

Polyamide thin film composite membranes usually are applied for water treatment processes such as reverse osmosis, forward osmosis and nanofiltration, and have been paid great attention in the radioactive wastewater treatment. Radiation which is a special characteristic for the radioactive wastewater compared to the traditional wastewater has challenged the stability of the organic separation membrane. This study started from the source analysis of the radioactive wastewater, and introduced the radiation effect on the surface color, separation performance, microstructure, surface functional groups and hydrogen bonds, hydrophilicity, element composition and mechanical properties. Then, the crosslinking and degradation mechanism of membrane material induced by radiation was discussed, and the feasibility of the radioactive wastewater treatment by polyamide membrane was analyzed. Finally, several problems related to radiation effect of polyamide thin film composite membrane were proposed. The radiation effect of polyamide composite membrane studied in this paper had a significant reference value in the analysis of effect of radiation on the structure and performance of composite membrane, exploration in the radiation damage mechanism of organic membrane and design on the radiation-resistant separation membrane.

Biogas residue was a solid residue produced by anaerobic fermentation of biomass, which was also a secondary resource with great application potential. Compared with the traditional biogas residue treatment process such as landfill and incineration, the use of thermochemical method to treat waste biomass biogas residue could achieve the fixation of organic matter in the biogas residue, and the prepared biogas residue biochar had stable structure and excellent performance, which could be widely used in pollutant adsorption, catalytic degradation, soil remediation and many other fields. This paper summarized the common preparation technologies and modification methods of biogas residue biochar at home and abroad, and focused on the structure, elemental composition and physical and chemical properties of biogas residue biochar. At the same time, the main resource application ways of biogas residue biochar were summarized, and the development direction of biogas residue biochar resource utilization in the future was prospected.

Since refractory nitrogen heterocyclic compounds in nitrogen-rich industrial wastewater aggravates the imbalance of carbon to nitrogen ratio and inhibits the nitrification and denitrification process in biological nitrogen removal process, exploring a new treatment process has become the inevitable course to efficiently treat low C/N industrial wastewater. Mixotrophic technology combines the metabolic pathways of heterotrophic and autotrophic nitrogen removal to optimize the nitrogen removal performance of low C/N industrial wastewater and further realizes the quality and efficiency improvement of low C/N industrial wastewater treatment. This paper reviews the mechanism, advance and influencing factors of Fe-mediated biological nitrogen removal, sulfur-mediated biological nitrogen removal and bacteria-algal symbiosis processes in mixotrophic nitrogen removal processes, and expounds the characteristics of the three processes and the applicability of different types of low C/N industrial wastewater. From the perspective of optimizing electron donor, acceptor and metabolic pathways, it is proposed to increase the electron capacity and the electron transfer rate, combining the electrochemical and coupling Fe-S system to enhance the collaborative metabolism, and improve the metabolic performance of pollutants.

Lignin as the most abundant resource of aromatic compounds in nature, can be degraded by oxidative depolymerization to produce aromatic aldehydes containing functional groups, which is an effective way to realize value-added utilization of lignin. Aromatic aldehydes are used as the important flavor compounds in food industry, synthetic dyes, perfumes, pharmaceutical intermediates and bulk chemicals, which are now mainly produced from petrochemical industry. In this review, the latest research progress of production of aromatic aldehydes from lignin is elaborated, including chemical oxidative depolymerization, electrochemical depolymerization, photocatalytic depolymerization, and biological depolymerization, especially, focusing on the conversion yield and selectivity of aldehydes to compare the cons and pros of various catalytic depolymerization process.Based on the characteristics of different catalytic depolymerization process, this paper analyzes the future research directions for the production of aromatic aldehydes from lignin. It is pointed out that existing catalytic methods still have various limitations for the large-scale industry production, and multi-method coupling is a promising strategy to further improve the aldehyde yield.

Amino functionalized dialdehyde starch (NH₂-DAS) was successfully synthesized by Schiff base reaction of DAS with hydrazine hydrate. During the preparation process, dialdehyde starch (DAS) was firstly prepared using starch as raw material and NaIO₄ as oxidant. The morphology, element distribution, thermal stability and surface chemical property of the NH₂-DAS adsorbent were characterized by SEM, EDX, XRD, TGA, FTIR and XPS. The adsorption behavior and adsorption mechanism of NH₂-DAS adsorbent toward Pb(‍Ⅱ) from aqueous solution were studied. The results showed that the adsorption behavior of Pb(‍Ⅱ) onto NH₂-DAS adsorbent could be well described by Langmuir isotherm model and Pseudo-second-order kinetic mode. The NH₂-DAS exhibited a high adsorption capacity of 165mg/g toward Pb(‍Ⅱ) at adsorption temperature of 45℃, pH=5.5 and the adsorption time of 240min. The adsorption of NH₂-DAS on Pb(‍Ⅱ) mainly depended on the coordination bonds between—C\stackrel{}{̿}N—, —NH₂ groups and Pb(‍Ⅱ) ions. The adsorption process was a spontaneous, endothermic and entropy increase process. After five times of regeneration test, the adsorption capacity of NH₂-DAS for Pb(‍Ⅱ) was still above 84.8% of original adsorption capacity. Therefore, the NH₂-DAS adsorbent had potential application prospects in the removal of Pb(‍Ⅱ) ions from aqueous solution.

To solve the heat loss and pollution caused by the exhaust gas of gas boilers, this paper proposed a synergistic system for waste heat recovery and low nitrogen oxides combustion. The system used heat exchanger and heat pump evaporator to recover waste heat of flue gas in different stages to realize deep waste heat recovery and waste water recovery of flue gas, and achieve the effect of "wet plume removal". Meanwhile, the recycled hot water was used to heat the humidified and combustion air, achieving nitrogen reduction effect of flue gas. A heat pump flue gas waste heat recovery and nitrogen reduction experimental bench was built. The results showed that when the return temperature and the return flow of the heating network were respectively 40℃ and 1853L/h, experimental system could reduce nitrogen oxides emissions by 60.6%, and the exhaust gas temperature could be reduced to 24.5℃. The system could recover 6.9% of the heat while maintaining a minimum nitrogen oxides emission of 39.7mg/m³, which meant that the system could meet the high-efficiency and clean production requirements of the energy system at the same time. In addition, the annual amount of residual water recovery was 20.2—31.2t/a, which proved that the system can synergistically deal with condensing waste heat recovery, nitrogen emission reduction, residual water recovery and whitening of gas boilers. The minimum payback period of the system investment was about 4.0 years.

Thermal-alkaline pretreatment is an effective method to improve the anaerobic digestion of waste activated sludge. In order to reduce the cost of treatment process, the refinery spend caustic (RSC) was used instead of fresh alkalis, and the effects of thermal-RSC pretreatment on anaerobic digestion of refinery waste activated sludge (RWAS) were investigated. The results showed that thermal-alkaline pretreatment significantly promoted the solubilization of RWAS, and the concentrations of proteins, polysaccharides and volatile fatty acids (VFA) increased with temperature and RSC dosage increasing, which were 1338.7mg/L, 510.9mg/L and 651.2mg/L at 90℃ with 4% RSC, respectively. Person correlation analysis showed that RSC dosage was positively correlated with fluorescence intensity of humic acids and melanoid production, while had a significantly positive correlation with the stagnation period of anaerobic digestion, which resulted in an inhibition of RWAS anaerobic digestion within high RSC dosages. Eventually, the combination of high temperature and low alkali (90℃, 1%RSC) was preferred. Under this condition, the SCOD degradation rate and maximum VFA production of RWAS by anaerobic digestion were 66% and 736.2mg/L, respectively. The methane (95.3mL/g-VS) and hydrogen (11.5mL/g-VS) production increased 5-fold and 3-fold compared to untreated sludge. Therefore, RWAS anaerobic digestion using thermal-RSC pretreatment has high application potential.

Using coal liquefaction residue (CLR) as the raw material to prepare CO₂ adsorbents can effectively improve the economic and environmental value of direct coal liquefaction process while achieving carbon emission reduction, which is of great significance. The direct liquefaction residue of Shenhua coal was used as carbon source, and the CO₂ adsorbents with better adsorption performance were prepared through the process of pre-oxidation and carbonization activation. The microstructure, pore size structure and adsorption properties of the adsorbents were characterized and tested by thermogravimetric analyzer (TGA), low temperature nitrogen adsorption instrument (BET), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that the adsorbents prepared from low ash liquefied residue had higher specific surface area and more microporous structure, which were more conducive to the adsorption of CO₂. The CO₂ adsorbent prepared from low ash liquefied residue under optimal activation conditions (mass ratio of activator/raw material was 1∶1, heating rate was 5℃/min, activation time was 1h) showed good adsorption performance. The CO₂ adsorption capacity at 40℃ and 15%CO₂ simulated flue gas was 4.47%. At 0℃ and 1bar, the CO₂ adsorption capacity could be up to 27.70%, the low temperature adsorption performance was excellent, the adsorption rate was fast, and it had good cycle stability.

The graphitized biochar WSC600K-B was prepared using waste walnut shell as raw material and KOH as modifier. The material was characterized by SEM, TEM, BET, XRD and Raman spectrum. The adsorption performance and mechanism of sulfamethoxazole (SMX) by WSC600K-B were investigated. The results showed that after activated by KOH, the surface of WSC600K-B presented orderly graphite lattice articles, the corresponding I_D/I_G was 1.037,and the degree of graphitization was high. The pore structure of WSC600K-B with honeycomb briquette shape was greatly improved, the pore was uniformly distributed, and the specific surface area increased to 733.64m²/g. At room temperature and pH=5, the removal rate of 50mg/L SMX by 0.25g/L WSC600K-B could reach 94.28%, and the adsorption capacity was 203.64mg/g. The adsorption process was significantly affected by pH and coexisting ions. The higher the pH value, the lower the adsorption efficiency. Coexisting ions inhibited the adsorption process. The adsorption process was in accordance with the second-order kinetic model and the Freundlich isothermal model, which was a multi-molecular layer chemical adsorption. Pore filling, π-π stacking, hydrogen bonding, hydrophobic interaction, and electrostatic interaction occurred during the reaction and the adsorption behavior was a spontaneous exothermic reaction.

The rigid structure of cellulose molecules is considered a serious impediment to the cellulose hydrolysis by cellulase. The disaggregation of cellulose by the addition of auxiliary proteins is an effective strategy to make the contact of cellulase with cellulose easier. Based on the documented α-glucosidase, a member of the glycoside hydrolase family 4, exhibiting synergism with the cellulase, and the analysis of protein homology as well as structure, a conjecture that the malate dehydrogenase (MDH) had a similar synergistic function was proposed. The theoretical and experimental studies on the hydrolysis of filter paper by the MDH synergism with cellulase were carried out. The interaction between MDH and crystalline cellulose was simulated by molecular docking. Theoretical analysis showed that the MDH could reduce the aggregation of cellulose by the effect of hydrogen bonds and hydrophobic interaction. The cellulose hydrolysis by the MDH synergism with cellulase, involving the addition of MDH, the amount of cellulase and the hydrolysis time were investigated. It was found that the yield of reducing sugar in the system of (50±0.50)mg filter paper, 150μg MDH and 0.06FPU cellulase was approximately 3.47-fold higher than the system of cellulase alone under the condition of hydrolyzing 24h in a water bath at 50℃. An enhanced activity of 247%±28% was acquired for cellulase by the synergic effect of MDH. The scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to analyze the filter papers before and after adding the MDH. Results showed that the MDH could destroy the crystalline regions of the cellulose, synergistically improving the efficiency of cellulose hydrolysis by cellulase. As an effective auxiliary protein, the MDH would provide an alternative for cellulose hydrolysis.

At present, many researches on membrane distillation with porous ceramic membranes have been conducted. However, due to the hydrophilic characteristic of the ceramic membrane, hydrophobic modification is required before use. It results in the increase of process and cost, and the hydrophobicity of the membrane gradually weakens with time. Therefore, the membrane distillation of desulfurization wastewater with negative pressure using porous ceramic membrane was proposed. The hydrophilic porous ceramic membrane was directly adopted. The negative pressure of the solution stream was formed by the suction effect of pump, thus the solution was prevented from permeating through the membrane. To explore the heat and mass transfer mechanism of membrane distillation with negative pressure, the performance of hydrophilic and hydrophobic porous ceramic membranes under different operating conditions were experimentally compared. The results showed that when the negative pressure in the membrane tube was lower than the capillary pressure in the membrane pores, the solution transport and water vapor transport occurred respectively in the pores of the hydrophilic and hydrophobic porous ceramic membranes. For air flow rate of 22L/min, wastewater temperature of 50℃ and flow rate of 11L/h, the permeation flux of the hydrophilic membrane was in the range of 1.9—3.9kg/(m·h), while that of hydrophobic membrane was only 0.13—0.25kg/(m·h). The thermal efficiencies of hydrophilic and hydrophobic porous ceramic membranes were about 92% and 55%, respectively. This indicated that thermal efficiency of the hydrophilic membranes was larger, and the high thermal conductivity of ceramic membrane favored the enhancement of the membrane distillation performance. The flow rate of desulfurization wastewater had little effect on the heat mass transfer performance, and the membrane permeation flux increased with the increasing of air flow rate or wastewater temperature.

In order to investigate the feasibility of synthesizing polyhydroxyalkanoates (PHAs) from sulfate organic wastewater through anaerobic treatment, a five-compartment anaerobic baffled reactor (ABR) was utilized to enrich PHAs-producing bacteria using sulfate organic wastewater as substrate, and the effects of different influent COD/SO₄^2- ratios (12.5, 9.3 and 4.0) on PHAs synthesis efficiency of granular sludge in the acidogenic sulfate-reducing phase (the first and second compartments) of ABR were examined to explore the PHA synthesis pattern in this system. The results showed that as the inflow COD/SO₄^2- ratio decreased, the removal of COD and SO₄^2- in the acidogenic sulfate-reduction phase shifted downstream. In the first compartment, the dominant microbial metabolism type was the butyric acid type, while in the second compartment, it shifted from the acetic acid type to the butyric acid type. The compartment with high content of PHAs in the granular sludge shifted from the first compartment to the second compartment. The best PHAs synthesis effect was observed when the inflow COD/SO₄^2- ratio was 9.3, which led to a large enrichment of PHAs-producing bacteria and high production of PHAs in the granular sludge of the acidogenic sulfate-reduction phase. The PHAs-producing bacteria in the granular sludge were large, and the PHAs granules were densely distributed throughout the bacterial cells. In the acidogenic sulfate-reducing phase, there existed a bio-chain cooperation relationship among acid-producing bacteria (APB), fatty-acid utilized sulfate reducing bacteria (FSRB) and acetic-acid utilized sulfate reducing bacteria (ASRB), and a large amount of PHAs was formed inside the bacterial cells. This study provided theoretical support for the resource utilization of sulfate organic wastewater.

In order to realize the harmless treatment and multi-stage utilization of biomass resources, this study aimed to explore the transformation process of organic matter and methane production characteristics during the anaerobic co-digestion of corn stover and aqueous phase derived from cellulose hydrothermal carbonization. The anaerobic co-digestion experiment of the two feedstocks was carried out. Compared with the mono-digestion, the addition of hydrothermal aqueous phase prepared at 200℃ (hold on 30min, 60min, 120min) and 230℃ (hold on 60min) increased the methane production by 7.32%, 4.42%, 22.08% and 21.76%, respectively, and the maximum accumulation of methane was 1387mL. The results showed that the prolongation of hydrothermal time and the increase of hydrothermal temperature had a positive effect on the final methane production. The inhibitors such as furan and its derivatives in the co-substrate did not have obvious negative effects on anaerobic co-digestion. While, it could be decomposed into furfuryl alcohol, etc. by microorganisms to promote methane production. The addition of hydrothermal carbonization aqueous phase promoted the growth of methanogens in the hydrogen reduction pathway of carbon dioxide, and promoted the production of methane in synergy with the methanogenic pathway of acetic acid. The results of this study could provide a theoretical basis for optimizing the anaerobic co-digestion process of corn stover and organic waste liquid of hydrothermal carbonization.

A Prussian blue-like compound (CoFe-PBA) was synthesized by a simple co-precipitation method for activating permonosulfate (PMS) to degrade organic pollutant bisphenol S (BPS). CoFe-PBA showed high activity on the removal of bisphenol S from activated PMS. Scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were used to characterize CoFe-PBA. The results showed that CoFe-PBA was composed of Co₃[Fe(CN)₆]₂, which was in nanometer scale. The surface was evenly distributed with C, Fe, Co, O elements, with abundant active sites. Under the conditions of catalyst dosage of 300mg/L, PMS dosage of 400mg/L and pH=5.89, the degradation system of CoFe-PBA/PMS could remove 73.77% BPS within 40min, and it was sensitive to acidic and coexisting ions (SO₄^2-, NO₃^- and Cl^-). The alkaline environment could promote the rapid activation of PMS. Repeated experiments showed that the system had good stability, and its activity only decreases by 26.70% after four repeated uses. The mechanism analysis showed that CoFe-PBA interacts with PMS, which changed the valence state of metal sites and produced various active substances to degrade BPS. The main active species was ¹O₂, and BPS was completely degraded through three degradation processes. The analysis of byproducts indicated BPS could be degraded to ring-opening products and finally be transformed to minerialzed products CO₂ and H₂O. Low energy consumption, low cost, rapid and simple preparation of CoFe-PBA provided ideas for green degradation of bisphenol S by activating PMS.