The energy utilization of CO₂ by chemical conversion faces two problems of energy consumption and hydrogen source. Photoelectrocatalytic technology is a new and clean way to realize the energy utilization of CO₂, which can reduce the external energy input and improve the selectivity and controllability of the CO₂ reduction products by excitation electron of photocatalyst and electrocatalysis. In this paper, the research progress of photoelectrocatalytic carbon dioxide is reviewed from the advantages of photoelectrocatalytic process, reaction mechanism, catalysts and the latest research results. We mainly elaborate the composition of the photoelectrocatalytic system, the electronic reduction of CO₂, and the existing problems. Besides, we mainly discuss on the influence of the compositions of the electrode material and the electrolyte, and the types of commonly used photocatalysts on the catalytic performance of the entire photoelectrocatalytic system. In addition, it points out that the current photoelectrocatalytic utilization of CO₂ has problems of insufficient conversion efficiency, poor product selectivity, and etc. Future research should focus on the development of high-efficiency photoelectrocatalysts and the catalytic kinetics.

Separation of olefin/paraffin is one of the vital important processes in chemical industry. The traditional cryogenic distillation usually exhibits low selectivity and high energy consumption. As the “green solvents”, ionic liquids (ILs) have tunable structures and high olefin solubility, which provide a novel route for efficient and energy-saving separation of olefin/paraffin. In this paper, the recent advances on ILs for the separation of olefin/paraffin were summarized. The separation performances of conventional ILs, functionalized ILs and silver-based ILs were emphasized and the effects of cations, anions, functional groups and mental ions on separation performance were discussed. The characteristics of three ways that introducing transition metals into ionic liquids, as well as the influence of the proportion of transition metals and the types of organic ligands on the separation performance of ionic liquids were emphatically introduced. Meantime, the future research challenges and perspectives of ILs in olefin/paraffin separation have been also posed.

At present, most of the numerical simulations of the internal flow field of the decanter centrifuge adopt the traditional Euler model, studies on the microscopic behavior of solid phase particles such as salt-out have been rarely reported. In this paper, based on the Eulerian multiphase flow model and RNG k-ε turbulence model coupled with the population balance model, the three-dimensional salt-out two-phase flow field of decanter centrifuge was numerically simulated with a computational fluid dynamics software Fluent. The distribution and change law of crystal particle size and crystal particle fraction and concentration of salting-out flow field in decanter centrifuge were obtained by the combination of simulation and experiment, and the distribution characteristics of crystal particles in the flow field with salting out in the decanter centrifuge were preliminarily revealed. The results show that the particle size of the salt-out crystal in the decanter centrifuge increases with the increase of the radius of the liquid ring. The particle size near the front wall of the spiral blade is obviously larger than that on the back side of the spiral blade, the crystal particle size distribution from the liquid discharge end to the solid discharge end has an overall axial particle size gradient which gradually becomes larger; The crystal particle size in the flow channel decreases with the increase of the drum rotational speed, and increases with the increase of the inlet solid phase volume fraction; The fraction of large size crystals is relatively large outside the liquid ring and near the front surface of the spiral blade, while the distribution law of the fraction of the medium and small size crystals is opposite; On the outside of the liquid ring, the concentration of salt out particle is higher and the distribution is uniform, and increases with the rotation speed of the drum. There are some similarities and differences between the results of PBM model and Euler model.

The traditional horizontal turbo air classifier normally has a tangential air inlet, which causes non-uniform flow flied distribution and low classification efficiency. Based on the previous research on the airflow path in the classifier, the traditional tangential air inlet was modified and two types of radial air inlet including a louvered one and porous one were designed in view of the whole flow field organization. Effects of the three air inlets on the classification performance were investigated experimentally. The result shows that the classifier equipped with the radial air inlets has the high coarse powder yield as well as the low fine particles mixing, indicating a deep separation degree of coarse and fine particles and high classification efficiency. The multi-layered structure of louvered air inlet helps to fully wash the coarse fraction, which reduces the probability of fine particles reporting to the coarse powder. Therefore, the classifier with louvered air inlet obtains the best classification performance, and its Newton classifying efficiency averagely increases 6% compared with the traditional classifier. Moreover, in case of the constant air volume, the inlet air velocity also affects the coarse powder yield, Newton classifying efficiency and classification accuracy index except for the cut size, and there exists a critical inlet air velocity for the better classification performance. The above results could provide new strategy to improve the performance of the turbo air classifier.

Focused on the recovery of dimethylacetamide (DMAC) from water, extraction-distillation method using ionic liquids as extractant was investigated and developed. First, solvent capacitys of DMAC with 384 types of ionic liquids at infinite dilution were calculated by COSMO-RS. After optimizing the structure of cations, [BMIm]FEP was finally determined as potential extractant. Then, the liquid-liquid phase equilibrium data of [BMIm]FEP-DMAC-H₂O were obtained, and binary interaction parameters were subsequently correlated by NRTL. Based on the binary interaction parameters, extraction process was designed by Aspen Plus. The designed result illustrated that when the initial concentration of DMAC was 10%, the mass ratio of [BMIm]FEP/water solution with DMAC was 2, and the number of theoretical plates reached 20, the recovery ratio of DMAC from water will be more than 99.5%. Finally, in order to evaluate the feasibility for using [BMIm]FEP as extractant, the energy consumption of three types of method were calculated. The result showed that compared with distillation method and the extraction-distillation method with chloroform, the energy cost of extraction-distillation method with [BMIm]FEP as extractant reduced 90% and 50%, respectively. It meant that the method was the most energy saving and the ionic liquid [BMIm]FEP showed its advantage for using as extractant to recover DMAC with low concentration from water.

Catalytic ozonation is an efficient wastewater treatment method, which is one of the widely adopted advanced treatment methods. The traditional modeling method is limited to the process of sewage treatment and cannot be used to investigate the influence of operating conditions on reactors or the spatial and temporal distribution of pollutant concentration. This study develops a multi-physics model for a catalytic ozonation reactor by coupling governing equations of the free and porous media flow, mass transport, and catalytic reactions. The model is capable of revealing the temporal and spatial distributions of key process parameters (e.g., the concentrations of pollutant and dissolved ozone, fluid velocity), which are difficult to be obtained through experiments. The simulation results on treatment efficiency are in good agreement with the experimental results. By resorting to this model, the influence of different operating conditions on treatment efficiency can be systematically analyzed towards optimized operation. The results show that without changing the key structure of the reactor, the optimal operating conditions are ozone concentration of 30—40mg/L, ozone inlet flow rate of 40—60mL/min, water circulation flow rate of 200—250mL/min, catalyst layer height of 600—800mm, and catalyst radius of 2mm. This study is helpful for understanding wastewater treatment reactor and optimal design of the reactor.

A novel technique is proposed for heat and mass transfer enhancement in a microchannel by introducing a freely rotatable square cylinder. A numerical model is developed based on the finite volume method and moving mesh technique to investigate the flow past the freely rotatable cylinder and its influences on heat and mass transfer enhancement. It is discovered that the cylinder is almost stationary when Re is low (Re=10). And its influence on the flow field and heat and mass transfer is thus similar to that of the static cylinder. With the increase of Re, the freely rotatable cylinder starts oscillating periodically owing to the interaction between the fluid and the cylinder, which leads to alternating vortex shedding behind the cylinder at Re=50. When Re rises to 100, both the oscillation of the cylinder and the downstream vortex structures are significantly strengthened. Compared to a static square cylinder at the same Re, a freely rotatable cylinder can disturb the original Poiseuille flow in the microchannel more significantly and break the thermal boundary layers on the heated walls, thus improve the heat transfer efficiency. In addition, the horizontal flow of the vortices can promote the mixing of solute in the microchannel. At Re=100, the average Nu on the walls is increased by 17.5% and 29.6% compared to static cylinder case and the no cylinder case , respectively. And the mixing efficiency will be increased by 70.5% and 65500% compared to static cylinder case and the no cylinder case , respectively.

The flow fields in the classifiers with or without the guide-vane were simulated and compared using ANSYS-Fluent 17.0 to study the effect of the guide-vane on the flow field in turbo air classifiers. The simulation results show that the airflow tangential velocity at the outer edge of the rotor cage is reduced because of the guide-vane. It influences the vortex distribution in the channel of the rotor cage and makes the steady operating conditions of these two structures different. The guide-vane can reduce the radial velocity fluctuation and turbulence dissipation rate near the outer edge of the rotor cage, where the flow field distribution is relatively uniform, and it is helpful to improve the classification accuracy. Besides, the guide-vane changes the velocity field distribution of the annular region through guiding the airflow. The tangential velocity of airflow decreases and the radial velocity increases. Increase of radial velocity leads to the increase of the cut size. The calcium carbonate classification experimental results show that the cut size is increased and the classification accuracy is improved for the turbo air classifier with the guide-vane. The large turbulent dissipation rate near the guide-vane is conducive to dispersing the powder, weakening the fish-hook effect obviously.

Partial nitrification is the prerequisite of start-up and operation of partial nitrification-anaerobic ammonium oxidation process for the efficient treatment of ammonia-rich wastewater. In this paper, the continuous flow internal circulation contact oxidation membrane bioreactor (ICCOMBR) for ammonia-rich wastewater treatment was constructed, and its start-up and operation characteristics were investigated. The results showed that under the conditions of seeding with activated sludge, water temperature 30℃, nitrogen load rate (NLR) 0.25kg/(m³·d), and dissolved oxygen (DO) 2.0—2.5mg/L, the part-nitrification of the bio-system could be realized successfully within 18d. The corresponding ammonia removal ef?ciency (ARE) and nitrite accumulation rate (NAR) reached 99.16% and 84.55%, respectively. Its volume nitrosation rate was 0.126gNO₂-N/(L·d)，while its volume nitrification rate was only 0.031g NO₃-N/(L·d). There was high linear correlation between the nitrosation rate and the alkalinity consumption. After the start-up of part-nitrification, the part-nitrification performance of the biosystem could be destroyed through decrease of the NLR to 0.1kg/(m³·d). With the decrease of the DO from 2.0—2.5mg/L to 1.0mg/L, the part-nitrification performance of the biosystem could be rebuilt within 6d, the nitrification ratio decreased from 71.4% to 11.1%, and its ARE and NAR reached 98.87% and 83.65%, respectively. Within 57d, the biomass in the biosystem increased from initial 1.85gVSS/L^{to 3.47gVSS/L.}

Coal direct liquefaction technology is one of the important technical ways to alleviate the contradiction between oil supply and demand and realize clean and efficient utilization of coal. The viscosity-temperature characterization of coal oil slurry has an important influence on its preparation, transportation, pressure, and preheating and reaction performance. This paper reviewed the research progress of the viscosity-temperature characteristics of coal oil slurry in terms of its changing rules, research methods, changing mechanism and influencing factors. During the heating process, the rheological properties of coal oil slurry were characterized by non-Newtonian fluid and shear thinning. There were four main methods for measuring viscosity under high temperature and pressure. The change mechanism of viscosity-temperature characteristics was analyzed. The change of viscosity in coal slurry preparation and heating stage was mainly caused by swelling, and in high temperature stage was mainly caused by asphaltene (especially pre-asphaltene) produced by coal pyrolysis. The effects of solvent, coal properties (coal rank, macerals and particle size distribution), shear rate, concentration of coal oil slurry, catalysts and hydrogenation pressure on the viscosity-temperature characteristics of coal oil slurry were analyzed. Finally, the research direction of viscosity-temperature characteristics of coal oil slurry in the future was pointed out, which could provide reference for the further development of coal direct liquefaction technology in China.

Surfactin is a kind of lipopeptide biosurfactants which are produced by Gram-positive Bacillus subtilis. Compared to chemically synthesized surfactants, biosurfactants have several advantages, such as lower toxicity, higher biodegradability, better environmental compatibility, and optimal stability in extreme conditions (e.g. high temperature, high pressure and high salinity etc) . Microbial biosurfactants have been proved that they can be used for enhancing oil recovery effectively. However, only a few types of biosurfactants can be produced at large scale for industrial applications. This study reviewed the chemical structure and biosynthesis mechanism of surfactin biosurfactants, and the factors affecting its fermentation production process was also investigated. Different strategies were employed in order to reduce the cost of this biosurfactant, such as using cheaper raw materials, optimizing the composition of the medium and the reactor, etc. Moreover, the oil displacement mechanism of surfactin biosurfactant and its synergistic effect with chemically surfactants were systematically discussed, and new ideas were proposed for promoting its further application.

Aiming at the difficult problem of replacement and restart-up for heavy oil shutdown pipelines on offshore platforms, the Rheolab QC rheometer was used to analyze the start-up process and mechanical response characteristics for Lüda heavy oil and its emulsions. The water volume fraction, start-up temperature, static time and constant shear rate on the start-up yield stress were discussed. A small indoor restart-up loop pipe experimental apparatus was designed and built, which was applied to measure and verify the reliability of theoretical predictions for restart-up pressure. The experimental results showed that the start-up process of heavy oil emulsion can be divided into three stages: yield, damping and equilibrium stages. The start-up yield stress always reached the maximum value near the phase inversion point, decreased with the increase of start-up temperature, and increased with the increase of constant shear rate. Appropriate increase of start-up flow can shorten the start-up time of shutdown pipeline, but also increase the start-up pressure. The predicted value of start-up pressure was as much as 1—2 times higher than the measured value by the experimental device, based on the start-up yield stress. While the predicted value of start-up pressure based on equilibrium shear stress was in good agreement with the measured value; with an average relative error of 4.5%.

Cold start is quite important for the commercialization of proton exchange membrane fuel cell (PEMFC). In PEMFC cold start experiment, super-cooled water inside the cell has been observed by neutron imaging technology. Here, we have proposed a model to address the effects of super-cooled water on the PEMFC cold start performance. By introducing the icing probability function to describe the randomness of freezing process, we established a three-dimensional, transient and multi-phase mathematical model. The PEMFC cold start performance was investigated with various ionomer volume fraction in cathode catalyst layer (CL) and membrane thickness. The results showed that increasing the ionomer volume fraction in cathode CL could effectively promote the diffusion of product water from the cathode CL into the membrane, and thus water storage space inside the membrane could be utilized more efficiently. Moreover, reducing the membrane thickness helps to enhance the diffusion of ionomer water from the membrane into the anode CL, thereby alleviating the anode dehydration phenomenon at high current density.

As an emerging CO₂ capture technology, hydrate method has been widely accepted as a research focus owing to the environmental protective characteristic and simplified approach. However, a group of key issues involving slow formation rate and low gas storage caused by the relatively low speed of gas-liquid transfer remain to be solved. Based on the characteristics of 13X molecular sieve coupling TBAB promoter at 279.15—280.65K and 3.0—6.0MPa, the study explored the pressure drop curve and gas uptake in the formation process of CO₂/H₂ hydrate (39.8% CO₂/60.2% H₂). Furthermore, this study analyzed the impact of TBAB concentration and experimental pressure on its promotion effect and compare with the other research respectively. The outcome of this study indicated that compared with the hydrate formation process in TBAB solution by agitation, 13X molecular sieve coupled TBAB can significantly enhance the rate of pressure drop and the gas uptake of CO₂/H₂ hydrate. Nevertheless, with the increase of TBAB solution concentration, gas uptake climb to the peak first and then decreased at 279.15K and 3.0MPa. And the gas uptake follow the similar regular pattern with the increase of TBAB solution concentration at 280.65K and 3.0MPa. Additionally, the impact of 13X molecular sieve coupling TBAB promoter on the rate of pressure drop and the consumption of gas of CO₂/H₂ hydrate increased with the increase of experimental pressure.

In order to explore the synergistic effect of the functional groups in the co-pyrolysis of lignocellulosic biomass materials and hydrogen-enriched feedstock, Fourier transform infrared spectroscopy, thermogravimetric-mass spectrometry and pyrolysis gas chromatography-mass spectrometry were used for research. The Fourier transform infrared spectroscopy experiment showed that the main groups of the infrared spectrum of cellulose were CH₃, CH and CH₂. The thermogravimetric-mass spectrometry experiments of cellulose and polyethylene showed that the main hydrocarbon product was C₃H₈, and the addition of polyethylene increased the content of C₂H₄ remarkably. The pyrolysis gas chromatography/mass spectrometry combined experiment showed that the pyrolytic products of cellulose were mainly levoglucosan, and the addition of polyethylene made the content of hydrocarbons increase obviously. HZSM-5 catalyzed the increase of the relative content of aromatic products.The overall trend of the fluidized bed pyrolysis verification experiments are consistent with the PY-GC /MS experiments. On the basis of co-pyrolysis of cellulose and polyethylene, HZSM-5 can be added to achieve the best experimental results.

Ash analysis, filtration and centrifugation analysis were adopted to measure the content of solid particles in the FCC slurry oil from a residue fluid catalytic cracking (RFCC) unit in CNPC. The solid content measured by centrifugation method was about 2850μg/g, which was between those by the ash analysis and filtration methods. The centrifugation method results indicated that the strong adsorption between fine particles and the heavy components in the slurry oil was the key factor to obtain coke powder. Centrifugal method coupled with subsequent calcination could isolate and obtain certain amount of solid particles from the slurry oil. Then the solid particles and the original FCC catalyst were characterized by means of laser particle size analyzer, elemental analyzer, X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), scanning electron microscopy & energy spectrum analysis (SEM-EDS), etc. The fresh FCC catalyst was regular spherical and showed a size distribution in the range of 32－120μm, while the solid particles in the oil slurry were scattered and irregular with the particle size of 0.4－40μm, in which the fine catalysts were mostly between 1－30μm. The solid particles in FCC slurry oil mainly consisted of catalyst powder, coke powder, inorganic metal salts, such as alkali metal (K, Ca), antimony (Sb), and iron (Fe).

Coal microwave pyrolysis technology is a new idea for changing the current situation of high environmental pollution and poor efficiency in coal conventional pyrolysis field that combines microwave technology with coal pyrolysis technology. Because of effective improvements of the temperature-rising characteristics and the products distribution, catalytic microwave pyrolysis, which is belonged to coal microwave pyrolysis, is widely concerned in the field of coal chemical industry. Through the developmental history of low-rank coal catalytic microwave pyrolysis, the status of catalytic microwave pyrolysis at home and abroad is summarized in this paper. Addition of Fe, Co, Ni, Cu and other metallic compounds or char, activated carbon and other carbon materials used as microwave absorbent can obtain higher heating rate and more uniform temperature distribution to significantly improve the coal tar yield and quality because of enhancement of microwave absorption property. Meanwhile, some metallic compounds played double roles of microwave absorber and catalyst. Because of excellent electromagnetic and microwave absorption performance, good catalysis and cost-efficient of carbon-based absorbing microwave catalysts, the carbon substrates and catalytic active component are further analyzed, and the characteristics of three common preparation methods are also compared. At the end of paper, the key existing problems of carbon-based absorbing microwave catalysts in preparation process are analyzed, and an outlook of the practical prospect for low-rank coal catalytic microwave pyrolysis technology is proposed.

Based on the synthesis of nanosheets Al-MFI zeolite, isomorphous MFI nanosheets zeolite was synthesized by replacing aluminum source with gallium source. The obtained samples were characterized by XRD, SEM, BET and NH₃-TPD. The catalytic performances of ordinary ZSM-5 zeolite, nanosheets Al-MFI zeolite and nanosheets Ga-MFI zeolite were tested with aviation fuel. The results showed that it was indeed a kind of nanosheets zeolite with an MFI skeleton topology, with a large specific surface area (482m²/g) and mesoporous volume. Compared with aluminum atoms, gallium atoms became less acidic at the acidic site formed by silicon and oxygen atoms. This made nanosheets Ga-MFI zeolite inhibit the hydrogen transfer reaction at high temperature (600℃), reducing the secondary reaction of low olefins and the adsorption of coking precursors (aromatic hydrocarbons) on acidic sites. This led to higher catalytic activity and light olefin selectivity, resulting in heat sink 14.47% higher than that of nanosheets Al-MFI zeolite. The study provided technical support for the active thermal protection of hypersonic vehicles.

In recent years, oil pollution in water has caused wide concerns. Many studies have attempted to catalyze the degradation of oily wastewater by photocatalytic materials, but most techniques are still limited to ultraviolet light. In order to solve this problem, SiO₂/BiOBr composites which can be used under visible light were prepared by coprecipitation method using SiO₂ as the catalyst carrier. The material was characterized by XRD, XPS, DRS, BET and so on. It was found that BiOBr can be supported on the surface of SiO₂, and it can effectively increase the specific surface area of SiO₂, and thus can improve the adsorption performance. With n(Bi)∶n(Si)=1∶1, the specific surface area and the forbidden band width (E _g) of the material was 83.53m²/g and 2.79eV respectively, resulting in the best performance. When the composite material was used to catalyze different types of oily wastewater, the removal rates of engine oil, diesel oil and edible oil were up to 25%, 60% and 93%, respectively. Further, the photodegradation mechanism of diesel oil was analyzed in detail, and it was found that ·O₂ ^- was the most active group.

The immobilized 4-dimethylaminopyridine (DMAP) was employed to safely and efficiently catalyze the acylation of α-tocopherol in mixed solvents of hexane and acetone (4∶1). DMAP was covalently bound on the surface of silica gel by N-alkylation reaction and the maximum catalyst loading reached 0.89mmol/g at 100℃. Thermogravimetric analysis / (TG and DTG) indicated that thermal decomposition of DMAP took place at 180—330℃ and Fourier transform infrared spectroscopy (FTIR) analysis showed that the characteristic peak of DMAP appeared at 1658cm^-1. The mixed solvent of hexane and acetone (4∶1) with low toxicities exhibited high solubility to the substrates and hence improved the activity of the heterogeneous catalytic reaction. Next, the influence factors for the acylation of α-tocopherol were systematically investigated. The optimal experimental condition was molar ratio of succinic anhydride to α-tocopherol of 3∶1, the acylation temperature of 55℃ and the reaction time of 21h. Results indicated that the highest yield of α-tocopherol succinate was 91% . After the reaction, the immobilized DMAP was collected by filtration and reused. The results indicated that the activity of the recycled immobilized DMAP was still above 90% after being used for ten runs. After the filtration, α-tocopherol succinate could be easily purified by the recrystallization and the FTIR analysis confirmed the non-existence of DMAP in the product. The excellent results in this work suggest that this technology could become a promising candidate for the industrial production of α-tocopherol succinate.

To improve the stability of Ru-based catalyst under high temperature, a series of Ru-CeO _x /TiO₂ composite oxide catalysts were prepared by a liquid co-impregnation method. The influence of CeO₂ on the Ru-based catalysts for catalytic oxidation of HCl was investigated. The catalysts with different loading amount of Ce were characterized by TEM, XRD, N₂ adsorption-desorption, Raman and XPS, and the results were correlated with the catalytic performance. The results indicated that the introduction of Ce changed the interactions of the active phase of RuO₂ and the support TiO₂, and the formation of Ce-O-Ru structure decreased the catalytic activity. Nevertheless, the sintering of Ru active sites was suppressed and a high concentration of Ce³⁺ was generated which was favorable for the adsorption and activation of oxygen species. Finally, the Ru-CeO _x /TiO₂ composite oxide catalysts with a proper amount of Ce gave an excellent high-temperature stability and activity, and the appropriate mole ratio of Ru to Ce was 1.0.

Functional non-spherical microparticles are widely used in myriad applications, such as biomedicine, adsorption, sensing and detecting. Compared with other methods for preparing non-spherical microparticles, microfluidic technique has great advantages in the fabrication and regulation of micron-sized functional materials due to its excellent manipulation of microflows. By precisely controlling the flow and shear of fluids in microscale channels, microfluidic technology enables the controllable construction of microflows, microemulsions and microfibers of various morphologies and structures, which provides excellent templates for manufacturing non-spherical microparticles. Moreover, these non-spherical microparticles can be endowed with more functionalities by introducing functional materials, which greatly expands and enriches their applications. This review summarizes recent progress of microfluidic fabrication of functional non-spherical microparticles. Emphases are focused on controllable fabrication of functional non-spherical microparticles by using microflows, microemulsions and microfibers as templates.

Superhydrophobic materials have attracted more and more attention due to their wide applications in fields such as self-cleaning, anti-corrosion, anti-icing and drag reduction. In recent years, inorganic materials have shown unique advantages in the field of superhydrophobicity because they could easily construct a high specific surface structure with a special morphology. Starting with a brief introduction to the definition, development and application of superhydrophobic phenomena, this paper overviews three classical models of superhydrophobic theory, and then analyzes and summarizes some of the commercially available superhydrophobic materials. The research progress of superhydrophobic surfaces constructed by different kinds of inorganic materials is summarized. Finally, this paper summarizes some of the problems in the preparation of superhydrophobic materials, and proposes two main research trends in the future：one is to improve the material design from the bionic angle to prepare a multifunctional composite coating that has both strong adhesion and durability, the other is to reduce the cost of preparation to promote the scale up and practical use of the product.

The type and amount of promoters are essential for the hydrates formation. This paper mainly analyzes two types of promoters, the thermodynamic promoters and the kinetic ones. The effect of the concentration of the water soluble thermodynamic promoters and that of water insoluble thermodynamic promoters on hydrate equilibrium is analyzed. The effects of types and amounts of surfactants, nanoparticles and phase change materials on the induction time, gas storage and production rate of hydrate are described. In summary, all promoters have optimum concentrations and the combination of different type promoters is more beneficial to the hydrate formation. At present, most mechanism studies on the formation of hydrates with the addition of promoters are speculated from macroscopic phenomena. Some scholars have explored the microscopic effects of promoters on hydrate formation by Raman spectroscopy, X-ray diffraction and microscopic observation and more efforts should be made on such studies. The promoter addition amount is an important indicator and the correlation between the optimum promoter concentrations and the studying objects should be acquired.

With the development of new energy vehicles, we need find higher energy density materials to match the new battery system. Phosphorus-based material is considered as one of the most promising anode materials in the metal ion batteries system due to its high specific capacity, good rate performance, abundant resources as well as its low price. In order to improve the properties of phosphor-based material’s disadvantages, such as its super large volume expansion rate, poor cyclic performance and poor conductivity during the electrochemical process, combining the red phosphorus with different materials can achieve this goal. This paper summaries the research progress of composites of red phosphorus combining with different kinds of carbon materials intensively, the methods of synthesizing red phosphorus-carbon composites, structural design, electrochemical performance and the deficiencies of this kind of material as well as it’s solution. The combination of natural porous carbon and red phosphorus can not only ensure the electrochemical properties of the composite but also control the cost. What’s more, the different metal phosphides made up from red phosphorus and metal powder, including crystal structure of metal phosphide, preparation method, oxidation-reduction mechanism of electrochemical cyclic process as well as every material’s significance among the research of metal phosphides, are also summarized. The different metal phosphatides working in suitable environments will own unexceptionable effect. Finally, it is proposed to use the density functional theory and first principle in the researches of phosphor-based materials, and vacuum and supergravity to control the conversion of red phosphorus, realizing large-scale, low-cost and high-security application of phosphor-based materials in metal ion battery finally.

The silicothermic reduction is the dominating technology to produce magnesium. However, the detailed kinetic and numerical simulation study of this process has been rarely reported due to its high reaction temperature and complicated heat transfer mechanism. According to experimental data, the segmental model was established, which was then transformed into an accurate mathematic model. After that, a three-dimensional unsteady numerical model incorporating the mathematical model, radiation and heat conduction models was established and used to predict the magnesium reduction and temperature distributions in the retort. The results indicated that the minimum temperature in the retort reached 1203K in 2 hours and the average magnesium reduction extent increased to 66% in 4 hours. Finally, we pointed out that the increase of the outer layer of briquette number and the enhancement in the heat transfer efficiency of the retort center could improve this technique. Besides, this study also could be applied to enhance the heat transfer equipment design, and to forecast the practical industrial production so that lots of amount of laboratory investment can be saved.

The use of nanostructured surfaces to improve the pool boiling heat transfer has been recognized as an effective method. Graphene oxide (GO) nanocoating surface was fabricated by GO nanosheets self-assembly under nucleate pool boiling conditions in present study. And the saturated pool boiling heat transfer on the GO nanocoating surface and copper plain surface were experimentally investigated under atmospheric pressure and with distilled water as working fluid. A high-speed camera was used to visualize the bubble dynamic growth process, and the bubble departure diameter and frequencies at different heat fluxes were obtained. The results showed that the superheat of GO nanocoating surface was lower than that of the copper plain surface at the same heat flux. The critical heat flux (CHF) and heat transfer coefficient (HTC) of GO nanocoating surface reached 208W/cm² and 7.25W/(cm²·K) respectively, which increased by 66.4% and 86.9% compared to those of the copper plain surface. The enhanced heat transfer performance was attributed to the favorable wettability and superior thermal conductivity of deposited two-dimensional GO layers on the copper substrate. Additionally, visualizations at low heat flux showed that when compared to copper plain surface, the bubble departure diameter of GO nanocoating surface was smaller and the frequencies were higher and the nucleus sites were more. The GO nanocoating surface was more conducive to bubble growth and departure. And at high heat flux, the bubble coalescence on the copper plain surface was more severe than that on the GO nanocoating surface. That is, the GO nanocoating surface can delay the appearance of the vapor blanket over the heating surface which triggers the CHF.

This research aims to provide a feasible route to achieve the CO₂ reduction and utilization. With carbonate used as electrolyte, and inexpensive Fe, Ni and Ni-Cr as electrodes, a molten carbonate electrolyzer is established and CO₂ is facilely converted into novel carbon materials. Moreover, the impact of the electrolyte conformation, electrolytic temperature, current density and electrode material on the morphology of the synthesized carbon products are studied. Electron dispersive spectroscope (EDS), scanning electron microscope (SEM), transmission electron microscope (TEM), Brunauer-Emmett-Teller (BET) analyzer, X-ray diffractometer (XRD) and Raman spectroscope (Raman) are employed to characterize the element composition, morphology & structure, BET surface area, crystallinity and graphite crystal regularity of the prepared carbon materials. The results demonstrate that hybrid carbonates electrolysis under 450℃ to 600℃ prefers amorphous carbons generation. BET surface area significantly depends on the applied temperature, current density and electrolyte composition, where lower temperature and elevated current density provide carbon products with a higher BET surface area. Moreover, the ambient CO₂ could be controllably transformed into carbon materials with desirable microstructures such as carbon nanotubes, carbon spheres and honeycomb-like carbon through regulating the electrolytic parameters of electrolyte conformation, temperature, electrode materials, etc. Of all the synthetic carbon materials, carbon nanotubes exhibit the highest graphitization and the most ordered hexagonal graphite crystals. This work demonstrates a feasible route for the direct CO₂ conversion and facile synthesis of nanostructured carbons, fitting well with the sustainable concept.

The biochars were prepared in a lab-scale fluidized bed reactor, using rice straw(RS), rice husk(RH) and sawdust(SD) as raw materials. The influences of feedstock type and pyrolysis temperature(400℃, 500℃, 600℃) on the physicochemical properties and Cd²⁺ adsorption of biochar were researched, and the qualitative and quantitative analysis of adsorption mechanism was conducted. The adsorption process could be preferably described by the Pseudo-second-order kinetic equation and the Langmuir equation. The adsorption capacity at equilibrium of RS500 was up to 30.19mg/g, which was much higher than that of SD500. The ion exchange and precipitation with inorganic minerals contributed 24.95mg/g， serving as the dominant adsorption mechanism. However, the contribution percentages of inorganic minerals and π electrons were 49.70% and 38.21% respectively in the Cd²⁺ adsorption by SD500. With the increase of pyrolysis temperature, the complexation with oxygen-containing functional groups was weakened while the Cd²⁺-π interaction was strengthened. At the same time, the ion exchange and precipitation with inorganic minerals in the Cd²⁺ adsorption by rice straw biochar and rice husk biochar were strengthened firstly and then weakened as the pyrolysis temperature increasing, and the contribution of them reached the maximum at 500℃. Furthermore, the contribution of each adsorption mechanism in the process of Cd²⁺ adsorption by biochar followed this order: ion exchange and precipitation were the largest, followed by Cd²⁺-π interaction, and complexation was the least.

Graphene oxide (GO) was prepared by the modified Hummers method. The reduced oxidized graphene (RGO) was prepared by using hydrazine hydrate as a reducing agent and controlling the pH of the reaction to 10. The graphene-loaded nano-silver composites were prepared by hydrothermal synthesis using graphene as the support, silver acetylacetonate as the precursor and lithium borohydride tetrahydrofuran as the reducing agent. X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and other characterization methods demonstrated that the silver nanoparticles supported on graphene had good crystallinity, uniform size and even distribution. The average diameter of the silver nanoparticles was about 8nm. Electrochemical tests of the graphene-loaded nano-silver composites by cyclic voltammetry and chronoamperometry showed that the graphene-loaded nano-silver composites had good electrocatalytic activity for the reduction of hydrogen peroxide. The linear range of hydrogen peroxide concentration measured by the hydrogen peroxide sensor constructed from the composite nanostructure was 0.1—62.3mmol/L (R=0.990) with the detection limit of 0.017mmol/L (S/N=3) and the response time of less than 2s.

Adsorption is an important method for CO₂ capture and separation. Recently, magnetic composites have attracted much attention for their ability to achieve rapid gas-solid separation. Herein, Fe₃O₄/NaA composites were rapidly synthesized by the hydrothermal method using dielectric barrier discharge (DBD) treatments for magnetic Fe₃O₄ nanoparticles and NaA sieve precursors, respectively. By using characteristics of X-ray diffraction, FTIR, SEM and SEM-EDS, the structure properties of composites were demonstrated. Meanwhile, the effect of the molar ratio of Fe₃O₄/NaA in composites on their CO₂ adsorption capacity and magnetic property were investigated. It was found that when the mass fraction of Fe₃O₄ was 23.2%, the Fe₃O₄/NaA composite showed both excellent CO₂ adsorption capacity （2.10mmol/g） and magnetic properties (25.92emu/g). More importantly, with good cycle stability of CO₂ adsorption, Fe₃O₄/NaA composite provided an excellent magnetic CO₂ adsorbent for potential fast magnetic gas-solid separation in the fluidized bed for CO₂ capture.

Dialdehyde carboxymethyl cellulose (DCMC) was prepared by selective oxidation of sodium periodate with carboxymethyl cellulose (CMC) as raw material, then it was chemically crosslinked with gelatin through “Schiff base bond” and mixed with sepiolite to obtain cellulose-based organic-inorganic hybrid composite film. The uniform dispersion of the microfibrous sepiolite in the DCMC/gelatin aqueous solution was achieved under ultrasonic treatment, in which the hydrogen bond was formed between the components, then the resulting solution is dried under vacuum to form the composite film. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), texture analysis were used to characterize the morphology, functional groups, thermal stability and mechanical properties of the film. The results showed that the mechanical properties have been significantly improved. When the addition amount of sepiolite was 0.5g, the elongation at break and tensile stress reached the maximum. At the same time, the composite membrane has a good thermal stability with the significant weight loss appearing in the range of 300℃ to 350℃. The adsorption experiments showed that the composite film show good adsorption to dye. For three selected dyes（methylene blue, malachite green, saffron T）, the adsorption capacity of the composite membrane increased with the increasing of sepiolite content, and reached up to 200mg/g when the amount of sepiolite was greater than 0.5g. Desorption experiments showed that the hybrid membrane could be regenerated by acid treatment and had good recycling efficiency. The synthesized biomass-based organic-inorganic hybrid composite film is well-sourced, biodegradable, and therefore has potential application in biomedical and pollution treatment.

Cerium carbonate [Ce₂(CO₃)₃] particles with flower-like structure were prepared from cerium nitrate[Ce(NO₃)₃] as raw material, ammonium bicarbonate（NH₄HCO₃) as precipitator and polyvinylpyrrolidone (PVP) as soft template by controlling initial PVP concentration, feeding reaction time and aging time. The cerium carbonate samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results showed that the optimum conditions for the preparation of flower-like cerium carbonate particles with uniform particle size and regular shape were as follows: initial PVP concentration was 2g/L and feeding reaction time was 1h with stirring speed of 300r/min at aging time of 4h. The mechanism of controlling the synthesis of cerium carbonate with special morphology by PVP was preliminarily explored. PVP adsorbs on the surface of cerium carbonate crystal through oxygen in ketone group, which hinders the growth of (002) and (040) crystal planes and limits the growth rate of crystal planes, thus regulating the morphology of cerium carbonate. The final product was organic-inorganic composites of PVP and Ce₂(CO₃)₃·8H₂O.

Biosynthesis of chemicals has the advantages of high efficiency, green and sustainable development. Acetyl coenzyme A, as an important intermediate of cellular metabolism in cells, is an important precursor for the synthesis of many biochemicals, and has played a vital role in the process of microbial carbon metabolism. Here we reviewed the synthesis and strategies of metabolic regulation of acetyl coenzyme A in Escherichia coli and its important applications. We also summarized the synthesis pathway of acetyl coenzyme A and the recent development of metabolic regulation strategies to increase the intracellular metabolic flux of acetyl coenzyme A production, these including metabolic regulation of the acetyl coenzyme A synthesized by acetic acid and pyruvate, metabolic regulation of the central carbon metabolic pathway and acetyl coenzyme A synthesized by beta oxidation pathway, and discovery of new pathways for acetyl coenzyme A synthesis. Finally, we prospected the feasible strategies of increasing acetyl coenzyme A supply and discussed methods of constructing cell factories for synthesizing acetyl coenzyme A as precursor chemicals by genome editing technology.

Bioaugmentation technology contributes to overcoming the adverse factors such as complex substrate types or negative environmental conditions in anaerobic digestion process, so it has been favored by researchers for years. Based on the types of bioaugmentation agent, the effects of bacteria-augmentation, fungi-augmentation, archaea-augmentation, syntrophic microorganism-augmentation and bio-enzymes-augmentation on the performance of anaerobic digestion were discussed. On this basis, the applications of bioaugmentation technology in lignocellulose substrates, ammonia-nitrogen/propionic acid-inhibited wastewater and refractory organic matters digestions were reviewed. Finally, the effects of attachment bioaugmentation and multi-stage bioaugmentation were discussed. Considerable researches have shown that bioaugmentation technology has a significant effect on promoting anaerobic digestion performance, while some studies have not achieved efficient results. The selection of bioaugmentation agents is the key to this strategy. The effects of bioaugmentation would be stabilized via building the microorganisms’ synergistic relationship or strengthening the enzymes’ stability in the system. In addition, the application of bioaugmentation technology in wastewater anaerobic treatment will be further expanded by choosing suitable attachment carriers and adding times.

Traditional microbial metabolic engineering strategy achieves the maximize of product yield by overexpressing or knocking out key genes, but this measure often unbalances the metabolic flux, and reduces the efficiency of production. Dynamic regulation of metabolic pathways for microorganism not only helps to maintain cell growth and balance metabolic flux, but also increases the productivity of target compound. In this paper, on the basis of signal sources, the dynamic regulation strategies at transcription level by two ways: one is artificial induction of dynamic regulation mode, which can dynamically regulate downstream metabolic pathway under the stimulation of exogenous signals that include light, temperature and chemical inducer by using some components such as the promoters responsive to the special signal; another is autonomous induction of dynamic regulation process, which can subsequently regulate the expression of key genes under the endogenous signals that include the change of intracellular metabolite levels and cell density by employing promoters, transcription factors, and ribonucleic acid switches. The application of dynamic transcriptional regulation strategies in microbial metabolic engineering were also introduced, and these will be prospectively applied in dynamic and adaptive expression for multiple genes in metabolic pathway construction to increase the target products yield.

Pretreatment tends to disrupt the recalcitrant structure of lignocellulosic biomass consisting predominantly of cellulose, hemicellulose and lignin, thereby improving the enzymatic hydrolyzability of the substrate. To avoid too long pretreatment time during the current atmospheric glycerol organosolv pretreatment process, acid was taken as catalyst in the pretreatment process to shorten the pretreatment time. The acid-catalyzed atmospheric glycerol organosolv (ac-AGO) pretreatment was optimized by single factor selection and response surface Box-Behnken design optimization as below:pretreatment temperature 245℃, pretreatment time 38min, sulfuric acid addition 0.1% (mass yatio). Under optimized condition, the prediction value of 48h enzymatic hydrolysis yield was 94.0%, and the practical value was 91.4%. Results showed that the response surface optimization scheme and regression model was fit. The ac-AGO pretreatment significantly improved the substrate hydrolyzability. Enzymatic hydrolysis of substrate at high solid concentration (15%—20%) underlined the outstanding enzymatic hydrolysability of substrate, with 72h enzymatic hydrolysis yield being 60% and glucose titer being 83.4g/L at 20% of solid content and 5FPU/g dry substrate of the enzyme loading. The ac-AGO pretreatment can significantly improve the enzymatic hydrolysis of lignocellulose substrate, making it possible to afford downstream ethanol fermentation industry with high-titer fermentable sugars.

In this paper, MGO was prepared by chemical co-precipitation method, span series surfactant was directly added to the reaction system to prepare surfactant-modified magnetic graphene oxide （SMGO) through one pot process. The results of X-ray diffraction(XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy(FTIR) indicated that SMGO was successfully prepared and performed well in magnetic separation. With GA as cross-link agent and Candida rugose lipase (CRL) as model enzyme, CRL was immobilized covalently on the SMGO materials. The activity recovery of Span40 MGO immobilized enzyme was 116.5%±1.7%, which was 6 times that of MGO immobilized enzyme; the specific activity was up to 32.5U/mg, 1.6 times that of free enzyme; k_cat/K_m was about 0.5 times higher than that of free enzyme. The storage stability and thermal stability were improved, and 73.6% of the relative enzyme activity was retained after 6 cycles of hydrolysis reaction. Preliminary analysis indicated that the surface of MGO was changed from hydrophilic to strong hydrophobic after modification, which simultaneously caused the activation of hydrophobic interface during the process of covalent immobilization. It was one of the reasons that increased the enzyme activity. The modification strategy reported in the article can provide new ideas for the modification of similar carrier.

Low-density proppant is a kind of high performance proppant prepared by chemical modification, physical modification and other methods. It has the characteristics of low-density and low settling rate. In this paper, based on the research of literature, according to the different modification methods,low-density proppant could be divided into low density porous uncoated ceramic proppant, porous inorganic coated low-density proppant, porous resin coated low-density proppant. We compared the different types of low-density proppant preparation system composition, density and pressure performance and summarized the mechanism of preparing different types of low-density proppant, the main influence factors and the proppant application. According to different preparation methods, ultra-light weight proppants(ULWP) were divided into two categories: conventional preparation and new technology preparation. The author suggested combining with various additives, optimizing the firing process, exploring the crystal structure such as corundum and mullite phase to realize effective combination of low-density and high strength of proppant. Hydrophobic modification and structure modification methods could be used to develop multi-functional, high performance proppant. All these were provided as reference for related research.

As the terminal wastewater of power plant, desulfurization wastewater has complex background. The water quality and quantity characteristics are affected by coal, limestone and the operation of desulfurization system, etc. The characteristics of desulfurization wastewater are introduced from the aspects of the tracer of pollutant composition. At present, the common zero liquid discharge treatment technologies of desulfurization wastewater can be divided into three units: pretreatment, concentration and reduction, transfer and solidification. Pretreatment mainly refers to double alkali method. Concentration reduction can be divided into two categories: membrane concentration and evaporation concentration. Transfer and solidification mainly include evaporation crystallization, bypass evaporation and fixation/stabilization. In consideration of the progress of zero liquid discharge treatment technologies of desulfurization wastewater at present, the paper proposed a solidification/stabilization of desulfurization wastewater with cement, and summarized the factors affecting solidification of chloride ion in cement industry. The solidification/stabilization of desulfurization wastewater with cement has broad development prospects, but more research is needed to improve the performance of solidified blocks.

Non-thermal plasma cooperating catalyst technology has been widely researched and applied in the treatment of volatile organic compounds (VOCs) due to its high efficiency, mild reaction conditions and simple equipment. The basic principle for non-thermal plasma synergistic catalytic degradation of VOCs and the research progress of the technology were introduced in this paper. It briefly describes the synergistic effect between the high reactivity of non-thermal plasma and the high-reaction selectivity of the catalyst, which improves the degradation efficiency of VOCs and cuts down the generation of harmful by-products as well. It also compensates the defects of high energy consumption and many by-products of single-use non-thermal plasma technology. In addition, it has been summarized including the combination mode and characteristics of non-thermal plasma combined with catalytic, the interaction and influence between non-thermal plasma and catalyst and the synergistic principle of non-thermal plasma combined with different types of catalysts. Complete mechanism analysis of non-thermal plasma cooperating catalyst technology is still unclear, and monitoring and analyzing the intermediate process are difficult in the application process, which are the important points in research of non-thermal plasma cooperating catalyst technology.

A new application strategy to treat the bottom ash of circulating fluidized bed boiler (CFB) was proposed to solve the problem of low utilization of bottom ash. After the bottom ash being rapidly water-cooled, it can be used as desulfurizer or the cement mixture. The experimental system for rapid water-cooling bottom ash was designed to prepare the samples of bottom ash at different temperatures. Then, the Yili ash and the cement of 42.5 grade were selected for the study, and the effect of rapid water-cooling bottom slag was investigated as mixed material on cement properties. The experimental results reveal that the way of rapid water-cooling destroys the shape of the ash particles, and cause change in the composition of the outer shell. The rapid water-cooling treatment not only gives rise to a significant decrease of the peak of CaSO₄, but also intensifies the characteristic peak of Ca(OH)₂. Compared with the original ash, the rapid water-cooling decreases the flexural and compressive strength under the same CFB bottom slag blend ratio, but it can shorten the setting time and reduce the stability value. Meanwhile, the rapid water-cooling can reduce the water requirement of the cement standard consistency and improve the compactness of the cement, it also has a positive effect on the mechanical properties and corrosion resistance of the cement.

The spent Ca-based sorbent after multiple calcination/carbonation cycles was put in the natural environment to be activated by absorbing the water in the environment. XRD analysis was employed to analyze the phase transition of the sorbent during the self-activation process. The CO₂ capture capacity of the sorbent after self-activation was then tested in a dual fixed-bed reactor. SEM and N₂ adsorption were employed to explain why self-activation process can enhance the CO₂ capture capacity of the spent sorbent. The results showed that the spent sorbent firstly absorbed the water in the environment to form Ca(OH)₂. The CaO in the sorbent completely converted to Ca(OH)₂ when the value of φ was 100%, and after that the sorbent continued to adsorb water to form Ca(OH)₂?2H₂O until the value of φ reach 170%. The self-activation process can enhance the carbonation conversion of the spent sorbent. The CO₂ capture capacity of the sorbent after self-activation process was proportional to the value of φ. Repetitive self-activation can enhance the carbonation conversion of the sorbent once again. Many new pores were formed on the grain surface of the spent sorbent during the self-activation process, and the values of pore volume and BET surface area increased, which made it easier for the diffusion of CO₂ in the sorbent to react with CaO. That is why self-activation process can enhance the CO₂ capture capacity of the spent sorbent.

With the development of industries, numerous wastes containing heavy metals from mining and smelting are discharged into soil, which has caused serious heavy metal pollution in soil and meanwhile poses a great threat to human health. Hence, this work takes the contaminated soil near a lead-zinc slag dumps as the research object. Tests on the stabilizing effect of heavy metal ions in contaminated soil by chitosan and its derivatives were carried out to screen the best stabilizing agent for the target heavy metals (Cd²⁺、Pb²⁺、Zn²⁺), and to probe the stabilizing mechanism. Furthermore, long-term stabilization effect of the screened stabilizing agent on heavy metal ions was studied under simulated acid rain leaching conditions. Both chitosan and its derivatives showed certain stabilizing effects on the heavy metal ions. Among them, carboxymethyl chitosan (CMCTS) had the best stabilizing effect by significantly reducing the migration and bioavailability of the heavy metal ions. The heavy metal morphology analysis, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis showed that stabilizing agents reacted with the heavy metal ions in soil to form complexes. Moreover, through mechanism analysis, it was further verified that CMCTS had the best stabilizing effect on heavy metal ions. The simulated leaching test indicated that CMCTS had long-term stabilizing effect to the heavy metal ions in soil which were not easily leached out by simulated rain and tended to exist in soil with a more stable form. More important, CMCTS could also improve the soil environment and enhance the stabilization of heavy metal ions by soil itself. Hence, CMCTS is expected to be a promising stabilizing agent candidate for the remediation of the soil contaminated by heavy metals (Cd²⁺、Pb²⁺、Zn²⁺).

The tungsten mining in southern Jiangxi has a history of 100 years. The heavy metal pollution of river depositions in the mining area poses a threat to the water environment. In order to explore the enrichment, occurrence and release of tungsten in the depositions of the Gannan River, the typical tungsten mining area in southern Jiangxi is selected. The Taojiang River was used as the research object. 36 surface deposition samples from the three water periods of Taojiang wet period-flat water period - dry season were collected and the total amount of tungsten was measured. The morphology of tungsten was analyzed by BCR three-step method and inductively coupled plasma mass spectroscopy. The simulation experiment explored the release law of deposition tungsten. The results showed that the content of tungsten in the surface depositions of the three water periods ranged from 0.91mg/kg to 159.94mg/kg, and the average value was 25.36mg/kg^{. The total content order of heavy metals was in dry season > wet period > flat water period, and the average tungsten content of 79.67% of the three water periods exceeded the soil background value of Jiangxi Province, the highest exceeded 39 times; the morphological analysis results showed that the main occurrence forms of tungsten in the three water periods were residual state, the proportion values were 80.38%, 91.59% and 86.71%, respectively, and the proportion of bioavailable states was relatively small, indicating that the ecological risk of heavy metal tungsten in the depositions of Taojiang was small. The results of single factor experiment showed that the release of tungsten in the depositions increased under the conditions of weak acid, high temperature and high concentration of NH₄ +, and the order of release of tungsten in the three water periods was in the wet season > flat water period > dry season, indicating that the unique water quality environment in Gannan was conducive to the release of tungsten from depositions.}

Flue gas recirculation, an effective way to inhabit NO_x formation, is widely used in the natural gas low-NO_x combustion process in chemical engineering, pharmaceutical and brewing industries. Its working mechanism attracts attentions from both academia and industry. Considering the effects of the internal/external flue gas recirculation (i-/e-FGR), two types of diffusion-combustion burners with weak/strong i-FGR were designed in this study. Combined with the e-FGR technology, pilot-scale (0.8MW) experiments were conducted to reveal the i-/e-FGR effect on the NO_x emission of the natural gas combustion. Additionally, Fluent simulation was also conducted. Results showed that i-FGR significantly restrained the NO_x formation while guaranteed a stable combustion. The initial emission of the burner with i-/e-FGR was far below that of the traditional burner. Combined with e-FGR, NO_x emission was maintained below 30mg/m³. Fluent simulation indicated that e-FGR dramatically decreased the flame temperature and O₂ concentration. The decrease of temperature played a decisive role in the suppression of the NO_x formation. When the NO_x emission was around 30mg/m³, the prompt NO_x mechanism dominated the overall NO_x formation, which drove a need to depress the prompt NO_x formation to further decrease the overall NO_x formation.

In order to investigate the influence of different ultrasonic density on the partial nitrification rapidly start-up, the partial nitrification start-up performance was studied by using different ultrasonic density treatment in SBR. The start-up time, nitrogen conversion, sludge performance and activity of ammonia-oxidizing bacteria (AOB) were investigated, and the variation of kinetic parameters of ammonia nitrogen removal during partial nitrification were studied. In the ultrasonic group (0.10W/mL, 0.15W/mL, 0.20W/mL, 0.25W/mL, 0.30W/mL), after 25 days of operation, the concentration of NO₂^--N reached 37.56mg/L, and the concentration of NO₃^--N was maintained below 10mg/L, the nitrite accumulation rate (NAR) was higher than 90%, and the ammonia oxidizing bacteria activity(SOURAOB) was 5.69mgO₂/(gMLSS·h), 7.91mgO₂/(gMLSS·h), 10.66mgO₂/(gMLSS·h), 12.80mgO₂/(gMLSS·h), 9.69mgO₂/(gMLSS·h), respectively. It was significantly higher than the control group [(3.93mgO₂/(gMLSS·h)].The ammonia nitrogen half-saturation constant (K_SN) of AOB obtained by double reciprocal method was 75.25mg/L, 23.15mg/L, 24.53mg/L, 9.78mg/L, 24.79mg/L, respectively. When the energy density was 0.10W/mL, K_SN of AOB was slightly larger than the control group (74.21mg/L), and the others were significantly smaller than 74.21mg/L. Therefore, ultrasonic treatment allowed AOB to preferentially obtained the substrate and achieve proliferate, and eventually rapidly realized partial nitrification.

The strong anti-deconstructive property of the bamboo （Phyllostachys pubescens Mazel） cell wall greatly limits its utilization as raw material in the fields of bioenergy, biomass-based materials, etc. Therefore, it is necessary to carry out pretreatment including main component separation to improve its utilization efficiency. In this work, microwave-assisted extraction of lignin from bamboo by using 1-ethyl-3-methylimidazolium acetate （EmimOAc） as solvent was carried out. The physicochemical properties of the obtained lignin fractions were characterized, and compared with the lignin extracted by EmimOAc using oil bath as heating source （110℃, 16h） and the alkali-soluble lignin extracted by 5% NaOH solution （50℃, 5h）. The results showed that the yield of lignin when EmimOAc was used as extractant under the microwave irradiation could reach 14.7% within 80min, which was more than twice of the yield （6.2%） when the lignin was extracted by EmimOAc using oil bath as heating source. Ionic liquid extracted lignin (ILL) and alkaline extracted lignin (AL) had a similar backbone structure, but under the effect of ionic liquid, more ester bonds between the ILL structural units were broken. Compared with AL, ILL showed higher thermal stability.