The carbon peak and carbon neutral target has been elevated to a national strategy, and relevant timetables, road maps and policy measures are being formulated and put into practice. As the world's largest energy consumer and carbon dioxide emitter, the proposal of the carbon neutrality target will trigger extensive and profound systemic changes in the energy field. It is urgent to explore new approaches for China's energy security and structural optimization oriented by the "double carbon" goal. Based on a horizontal comparison of carbon dioxide emissions and the development of energy technology in the United States, the European Union and China, as well as a vertical analysis of the characteristics of carbon emissions and energy consumption in China in recent years, the short-term strategy and long-term outlook for China's energy structure optimization were presented in this paper. On the basis of learning from the advanced energy science and technology policies of developed countries, it was suggested that China needed to base itself on its own national conditions, comprehensively consider its own energy resource endowment and the essential attributes of energy, use coal in a clean and low-carbon manner, utilize oil efficiently as a resource, supply natural gas in a diversified manner, and develop cleanly energy and continue to promote energy conservation and emission reduction in high energy-consuming industries. The prerequisite for carbon neutrality in the energy sector was to improve relevant policies and mechanisms, and took this as a guide to build a clean, low carbon, diversified and symbiotic energy system, continue to promote the collaborative innovation of "three-carbon" technology and energy digital technology, and construct an integrated intelligent energy system. Due to the complex evolution of the international situation, China's energy development should take into account the three goals of achieving the "dual carbon" goal, optimizing the energy structure and energy security. It was necessary for China to establish a dynamic and diversified energy strategic reserve system and energy cooperation mechanism to ensure energy security under open conditions.

With the continuous development of industrial technology, the heat transfer in traditional heat exchange tubes has been unable to meet the heat transport requirement under high heat flux. Twisted tape insert is a kind of heat transfer enhancement element which can effectively improve the heat transfer efficiency in heat exchange tube. It has been focused and studied widely by many scholars because of its simple structure and easy processing characteristics. The heat transfer performance and entropy production of fluid in the tube are generally used as important parameters to evaluate the performance of heat exchange tube. Therefore, the influences of twisted tape structure and working fluid on these parameters become the focus of research in recent years. This paper mainly reviews the research progress of the effects of different structural twisted tapes on heat transfer and entropy production in tubes in the past decade. Firstly, the twisted tapes used in the literature are classified according to the geometric structure, and the effects of different types of twisted tape on heat transfer, entropy generation and comprehensive performance of heat exchange tubes are expounded and analyzed, trying to find out the relationships between geometric structure and heat transfer performance as well as entropy generation in heat exchange tubes. Secondly, the research progress of composite heat transfer technology with twisted tape and nanofluid is introduced. Finally, the heat transfer and entropy generation models established by researchers to maximize heat transfer performance and minimize entropy generation are summarized, and the advantages and disadvantages of the models are evaluated.

To solve the problem of high energy consumption in the separation of dimethyl carbonate (DMC)/methanol (MeOH) azeotrope by traditional pressure swing distillation, an improved pressure swing distillation process assisted by heat pump was proposed, and the feasibility and economy of different heat pump schemes were explored. The research was carried out on the ASPEN PLUS simulation platform. The typical heat integrated pressure swing distillation process (H-PSD) was designed, and the energy bottleneck of the typical process and the direction of process improvement were analyzed based on column grand composite curves. Four types of heat pump assisted improved processes were proposed, and the design parameters of different schemes were obtained by simulation. The energy-saving effect and economy of different heat pump schemes were compared by using the methods of composite curve and economic analysis. The research showed that among four kinds of heat pump schemes, the vapour recompression heat pump with intermediate reboiler had the best economic performance. Compared with the typical heat integrated pressure swing distillation, the energy consumption, the total annual operating cost and the total annual cost of the system were reduced by 24.31%, 29.43% and 12.58%, respectively, which indicated the good energy-saving effect and economy performance of the heat pump assisted process.

For the safe use of hydrogen/methane premixed gas, the deflagration characteristics of hydrogen/methane premixed gas were studied by using gas-solid two-phase inhibitor. Using CO₂-sepiolite powder gas-solid two-phase material as explosion suppression material, the explosion characteristic parameters and inhibition effect of sepiolite powder and its concentration on hydrogen/methane premixed gas were tested by 20L spherical explosive device. The dispersibility of the powder was different under different jet pressure, which resulted in the production of the optimum explosion suppression concentration of the powder. Under the action of carbon dioxide alone, the hydrogen/methane premixed gas had a better inhibition effect when the hydrogen addition ratio was low, and the inhibition effect was poor for more than 50% hydrogen/methane premixed gas. Under the action of CO₂ and sepiolite powder two-phase inhibitor, the compound explosion sup-pressant had a good inhibitory effect on the hydrogen/methane premixed gas with high hydrogen content. In addition, the mechanism of gas explosion suppression was analyzed based on the element composition and pyrolysis characteristics of sepiolite powder.

In industry, SO₃ gas prepared by oxidation of SO₂ is of high concentration, strong corrosion and great cross-influence, and difficulty by high precision real-time detection. Moreover, the relationship between input flow and SO₃ concentration is not clear, which leads to that the parameter adjustment depends on experience. Aim at the above problems, a real-time system for detection of industrial SO₃ gas concentration was designed by AO2 electrochemical oxygen sensor, and a multivariate nonlinear regression model with input air, SO₂ flow and output SO₃ concentration was established. The real-time detection system of SO₃ gas concentration mainly included AO2 electrochemical oxygen sensor, sensor conditioning circuit, AD620 amplifying circuit and ADS1256 A/D conversion circuit. It indirectly measured SO₃ concentration by detecting the millivolt level change of O₂ concentration in input air and the output mixture gas from SO₃ generator. In this way, the cross influence of other sensitive gases was avoided. The experimental results showed that the detection time of the system was 27s, the sensitivity was 111mV/%, the deviation was less than 0.18% and the stability was good, which demonstrated the effectiveness of the detection system. A cubic polynomial nonlinear regression model for predicting SO₃ concentration was established by response surface method. The results of variance analysis for this model were very significant with the mean square error (MSE) of the model of 0.0007174 and the correlation coefficient (R²) of 0.9929, which proved that the model had good fitting degree and high prediction precision.

Considering the risks of hydrate formation and plug in the gas hydrate wellbore, experiments were conducted to investigate methane hydrate formation in bubbly flow using flow loop. Experimental results showed that the increases of flow velocities enhance the hydrate formation rates but the increases of xanthan gum concentrations reduced the hydrae formation rates. Based on gas-liquid mass transfer mechanism, a hydrate formation prediction model in bubbly flow was developed considering the influences of rheology of continuous-phase, and the breakage, coalescence and deformation of gas bubbles on the gas-liquid interfacial area and the gas-liquid mass transfer rate. Coupling with experimental data, an empirical formula of the overall mass transfer coefficient was proposed to describe the effect of interactions between gas bubbles on the gas-liquid mass transfer rates. Compared with experimental data, the developed model predicted the quantity of hydrate formation and the hydrate formation rate with the discrepancies within ±5% and ±15% respectively. The developed model contributed to forecast the hydrate risk in the oil, gas and natural gas hydrate wellbore and laid a theoretical foundation for developing an efficiency and economic hydrate management plan in wellbore.

During the aging process of fuel cell, the migration of catalyst in the catalytic layer and the increase of the particle size will deteriorate the performance of fuel cell. This paper proposed a new agglomerate layered distribution model, in which the layered interface can change linearly along the thickness of the film. Through the coupling of the macro-electrode model and the aggregate sub-scale model, the influence of the uneven distribution of aggregates on the performance of the proton exchange membrane fuel cell was analyzed by the finite element method. The results showed that the loss of catalyst near the outside of the aggregate had great influence on the battery performance. When the outer region without catalyst reached 10% of the radius, the current density decreased by 89.8% when the output voltage was 0.2V. When the inner region without catalyst reached 10% of the radius, the current density at the output voltage of 0.2V decreased by about 25%. Compared with the catalyst migration toward the proton exchange membrane, the catalyst migration toward the gas diffusion layer had greater impact on fuel cell performance. The fuel cell current densities from the layered and incrementally distributed agglomerate model and the layered decreasing distributions model were about 60% and 10% of those given by the uniformly distributed agglomerate model respectively. In addition, the performance of the cell could be improved by doubling the platinum loading.

There are often problems in geothermal wellbore that its production capacity of geothermal fluids decreases or even cannot be produced due to the scaling of geothermal fluids in it. Therefore, it is particularly important to study the scaling behavior, such as to predict the scaling location of geothermal fluid in the wellbore. Artificial neural networks (ANNs) can be used to develop a new model for predicting the scaling location in geothermal wellbore. Because it has no nature of mechanism modeling, it can only be used as a new proxy model. The three-layer ANNs structure was successfully trained using the temperature, pressure and well depth data of the geothermal fluids at the wellhead and bottomhole as input variables, and the appropriate accuracy of the ANNs proxy model was achieved with a relative error of less than 10%. The scaling locations predicted by the ANNs proxy model were analyzed and compared with the actual measured wellbore scaling locations, and the reasons for the errors were analyzed. The results showed that the new ANNs proxy model could serve as a practical tool to reliably predict scaling locations in geothermal wellbores.

As a fully biodegradable plastic, polybutylene succinate (PBS) is considered to be a potential degradable material to replace ordinary plastics. However, the cost of PBS is continuously rising because the price of its raw materials, especially 1,4-butanediol (BDO), is going up. In order to thoroughly understand the process, current situation, existing problems and latest development of BDO synthesis, different fossil-based BDO synthesis routes were reviewed, and the progress of Cu-, Ni-, Pd-, Pt- and Rh-based catalysts used were described. Subsequently, the latest development of the BDO synthesis derived from biomass such as succinic acid, furfural/furan, 1,4-anhydroerythritol and sugars were elaborated. Then the life cycle assessment, capital and operating costs of biomass derived BDO synthesis were briefly described. The comparison of BDO synthesis between bio- and fossil routes was given. Finally, the existing problems and development direction of BDO synthesis were outlined and expected. The key for synthesis BDO is to develop the low energy consumption and high efficiency catalysts for both the fossil- and bio-route in the future.

Para-xylene is an important aromatic material in petrochemical industry. In recent decades, China’s demand for para-xylene has been growing. In order to ensure the healthy and steady development of para-xylene industry in China, it is urgent to develop a more low-cost and efficient para-xylene production process. Shape-selective alkylation of toluene with methanol to para-xylene is one of the most promising and competitive new technologies for para-xylene production. However, how to improve the stability of the catalysts while maintaining their high selectivity is still challenging. The formation of low-carbon olefins is one of the main reasons for the deactivation of the catalysts. Based on the discussion of the catalytic reaction mechanisms and research progress of the catalyst, we believe that the exploitation of highly selective and stable catalysts can be driven from three directions: synthesis of molecular sieve parent of shape-selective effect and excellent diffusion property, coordinated regulation of the pore structure and acid properties of molecular sieves, and inhibition of the formation of low-carbon olefins.

Electrolysis of seawater is a renewable, sustainable, low-cost, and fresh-water-saving way for hydrogen production. The design and development of efficient and stable electrocatalysts has good application prospects for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in natural seawater or brine electrolyte. After exploring the current situation and challenges of seawater electrolysis, we have systematically summarized the design ideas and modification methods for seawater-splitting electrocatalysts. This review first introduces in detail the basic principles of hydrogen evolution, oxygen evolution, and chlorine evolution. The recently reported electrocatalysts for HER and OER that can work stably in seawater are subsequently discussed. For cathodic reaction, efficient noble-metal based catalysts and low-cost transition metal-based catalysts are analyzed. For anodic reaction, the nickel-based catalysts are focused and compared with other catalysts. Finally, challenges and development directions of seawater electrolysis are presented. In the future, different electrocatalysts with various structures for seawater splitting should be further developed. Highly efficient and stable cathode electrocatalysts and those with higher OER selectivity for anodic reaction should be designed to meet the requirements of industrial applications.

As an advanced oxidation process (AOP), heterogeneous Fenton oxidation can effectively solve the problems of traditional Fenton technology, such as narrow applicable pH range, easy to produce iron sludge, and difficult to recover catalyst, but its reaction activity is limited by the catalyst material. This paper introduces the application of MOFs and its derivatives in heterogeneous Fenton technology in recent years. The advantages of MOFs and their derivatives, such as large specific surface area, abundant active sites, and easy structural control, which could improve the bottlenecks of the heterogeneous Fenton technology, such as insufficient active sites, low Fe²⁺/Fe³⁺ cycle efficiency, and poor mass transfer efficiency, were analyzed. This work summarizes the research progress on modifying MOFs to obtain high activity catalysts, and points out the shortcomings of the current application of MOFs as catalyst materials. In the future, MOFs catalyst researches should focus on modification design for high activity and their commercial application.

Mesoporous TiO₂ photocatalysts (M-TiO₂) were prepared by nitrogen (N₂) plasma modification in a quartz plate dielectric barrier discharge (DBD) reactor. The M-TiO₂ were characterized by XRD, TEM, UV-vis DRS, BET and XPS techniques. M-TiO₂(CTP+C) and M-TiO₂(C+CTP) showed better visible light catalytic performance than M-TiO₂(C). When the molar ratio of CTAB/Ti was 1∶3, M-TiO₂(CTP+C) had the highest specific surface area (238.2m²/g), the narrowest band gap (2.51eV) and the largest O_V/O (35.7%). M-TiO₂(CTP+C) exhibited better catalytic activity and chemical stability, and the degradation rate of MO reached 90% within 240min of visible-light irradiation. The N₂ low temperature plasma modification can effectively improve the dispersion of M-TiO₂ grains and promote the conversion of Ti⁴⁺ to Ti³⁺. An enhancement of the visible-light catalytic activity of M-TiO₂ was obtained by the combined effect of oxygen vacancy, interstitial carbon and interstitial nitrogen. The results of active species capture experiment and Mott-Schottky curve showed that O₂^▪- and h⁺ played a major role in the visible-light degradation of MO. Based on the above observations, the mechanism model of M-TiO₂(CTP+C) visible light catalysis was given.

Trichloroethylene (TCE) is a widely used industrial raw material, but its emission seriously threatens the ecological environment and human health. How to efficiently remove TCE is still a crucial issue to be solved urgently. In this study, a series of Mn-Ce/HZSM-5 catalysts with different molar ratios of Ce/Mn were prepared by a deposition-precipitation method, and then used for the catalytic oxidation of TCE. The effects of various process parameters on the catalytic performance of the TCE decomposition were investigated using response surface methodology (RSM). The Mn-Ce/HZSM-5 catalyst demonstrated good catalytic activity for TCE decomposition, and MnCe_0.8/HZSM-5 catalyst exhibited the highest catalytic activity due to its high reducibility and abundant surface oxygen species. In addition, the RSM analysis results showed that temperature was the most significant factor affecting the TCE removal efficiency and CO₂ selectivity, followed by the gas flow rate and relative humidity (RH) in catalytic oxidation of TCE by MnCe_0.8/HZSM-5. The best TCE removal efficiency (77.1%) and CO₂ selectivity (70.0%) were acquired at a gas flow rate of 0.2L/min, temperature of 450℃ and RH of 16%. Moreover, the MnCe_0.8/HZSM-5 catalyst also showed good stability. The results provided an effective method for the removal of chlorinated volatile organic compounds.

A series of dysprosium doped Bi₂ZnB₂O₇(BZBO) photocatalysts were prepared by high temperature solid-state reaction. The crystal structure and morphology of BZBO: xDy³⁺ were detected by XRD, TEM and HRTEM. Effects of dysprosium doping with different concentration on their photocatalytic performance were investigated by degradation of RhB under UV light irradiation. The RhB photodegradation results revealed that the optimum photodegradation activity of Dy³⁺ doped BZBO (BZBO: 4%Dy³⁺) was 1.56 times higher than pure BZBO. The results of optical absorption indicated that the introduction of Dy³⁺ in BZBO could enhance absorption intensity in UV region and reduced forbidden band width of BZBO. The optical absorption, photoluminescence spectra, photocurrent and EIS experimental results demonstrated that the enhanced photocatalytic activity of BZBO: 4%Dy³⁺ was mainly ascribed to that the doped dysprosium in BZBO could promote the separation and transfer of photogenerated electron-hole pairs and improve photoabsorption ability of BZBO photocatalyst. Thus, BZBO: 4%Dy³⁺ exhibited the highest photocatalytic activity than that of other as-prepared samples under the effects of both rare earth elements and polarization electric field.

Although the traditional ammonia selective catalytic reduction (NH₃-SCR) has been widely used in the removal of atmospheric pollutant NO, there are still some flaws such as catalyst toxicity, high and narrow operating temperature, and ammonia emission. Herein, the manganese-iron bimetallic catalyst supported on SBA-15 molecular sieve was prepared by the impregnation method, and the performance of the manganese-iron catalyst to directly decompose NO under non-thermal plasma at low temperature was investigated. The activity test results showed that the NO conversion reached 97.8% when the plasma output voltage was 12kV at room temperature. The characterization results showed that the pore structure and physical morphology of the catalyst did not change significantly after the reaction. The online mass spectrometry analysis results showed that under the synergistic catalysis of plasma, NO was directly decomposed into N₂ and O₂. The mechanism analysis showed that the electron transfer between different valence Mn species weakened the N—O bond of the NO adsorbed on catalyst surface, and the energy consumption of the plasma to decompose NO was also reduced.

Catalytic conversion of saccharides is a promising way for the production of biomass-based fuel and high value-added chemical, and the utilization of microwave energy can make this process more commercially viable. In this paper, the efficient decomposition for fructose to 5-hydroxymethylfurfural (5-HMF) catalyzed over carbon nanotube-supported zirconia [ZrO₂/MWCNTs(C)] as a microwave response catalyst under microwave irradiation was investigated. Firstly, hydrothermal synthesis method was used to synthetize ZrO₂@MWCNTs(C) catalysts with high performance and then, they were characterized. Moreover, the effects of catalyst dosage, fructose concentration, reaction temperature and reaction time for the yield of 5-HMF were further investigated and lastly, by adjusting the participation of each component for composite catalyst during reaction, the microwave strengthening mechanism was revealed. Under a mild MW condition (at 120℃, atmospheric pressure), high 5-HMF yield about 74% after 10min reaction time was achieved which was significantly higher than that obtained under the conventional heating about 31%. With the optimum dosage of ZrO₂60/CNTs (50%), about 98% fructose conversion and about 92% 5-HMF yield could be achieved with microwave irradiation at 140℃ and atmospheric pressure for 10min. By exploring the coupling matching relation between the absorption performance of the supporting and the catalytic performance of the active site, the strengthening mechanism of the microwave synergistic catalytic process was revealed, which may be attributed to the combination of selective heating for carbon supporting and the active site of zirconia.

Modified Fischer-Tropsch catalysts, especially the CuCo catalyst, are potential industrial catalysts for ethanol and higher alcohols production from syngas, due to their high catalytic activity and total alcohols selectivity. A series of CuCoZr catalysts were prepared by evaporation-induced self-assembly (EISA) and co-precipitation (CP) method. The effect of preparation method and Cu/Co atomic ratio of EISA catalyst on its catalytic performance of ethanol and higher alcohols synthesis from syngas were investigated. The catalysts were characterized by N₂ physical adsorption-desorption, small-angle XRD, in-situ XRD, TEM, H₂-TPR, CO-TPD and in-situ DRIFT, and the reaction path of syngas on Cu₃Co₁Zr catalyst with Cu/Co atomic ratio of 3∶1 was analyzed. The results showed that CuCoZr catalyst prepared by EISA method possessed ordered mesoporous structure, and the specific surface area increased firstly and then decreased as the Cu/Co ratio. Cu₃Co₁Zr catalyst showed the largest specific surface area and CO adsorption capacity, which were 143m²/g and 0.33mmol/g, respectively. Moreover, the crystalline size of Cu was only 9.1nm. During the catalytic reaction, Cu₃Co₁Zr catalyst gave a CO conversion of 74.9% and a higher alcohol yield of 75.2mg/(g_cat·h) with ethanol mole fraction of 31.0%, much better than those given by the co-precipitated CuCoZr-CP catalyst with the same composition.

The Ti-modified alumina was obtained by template method and used as support to prepare CrO _x /nTi-Al₂O₃ catalysts, and the influences of Ti loading on the catalyst structure and catalytic performance for propane dehydrogenation were investigated. X-ray diffraction(XRD), N₂ adsorption-desorption, transmission electron microscopy(TEM), Fourier transform infrared spectroscopy(FTIR), UV-Raman spectroscopy, X-ray photoelectron spectroscopy(XPS), NH₃-temperature-programmed desorption(NH₃-TPD) and pyridine-infrared spectroscopy(Py-IR) characterizations were carried out to elucidate the catalyst properties. The results showed that CrO _x /nTi-Al₂O₃ catalysts possessed uniform foam-like mesoporous structure with micropore and high specific surface area of 180—195m²/g. The main chromium species on the catalysts were Cr⁶⁺ and Cr³⁺. Among them, the Cr⁶⁺ species existed in the form of monochromate and bichromate, and Cr³⁺ species existed in the form of crystalline α-Cr₂O₃ and high-dispersive non-redox Cr₂O₃. The Ti loading decreased Cr⁶⁺ content on the catalyst surface and increased high-dispersive Cr³⁺ content in the pore channel. The Ti loading decreased weak acid intensity and promoted the formation of medium acid sites, meanwhile the amounts of Brönsted and Lewis acid sites were obviously decreased. The propane conversion and propylene yield on CrO _x /nTi-Al₂O₃ were obviously improved by adding 0.5%—1.0% TiO₂(mass), but excess Ti (>2%TiO₂) could decrease the propylene selectivity and yield. The oxidation dehydrogenation of propane took places on Cr⁶⁺ species, which were reduced to redox Cr³⁺ species, and then the redox Cr³⁺ species continuously catalyzed the propane dehydrogenation. Meanwhile, the high-dispersive non-redox Cr³⁺ species in the pore channel directly catalyzed propane dehydrogenation to produce propylene. The aboved-mentioned Cr active sites provided both high catalytic activity and good stability.

Rational design of efficient electrocatalysts is critical for electrochemical reduction of carbon dioxide (CO₂ER) to high value-added chemicals and fuels. Herein, a hydrothermal-calcination method was developed to prepare flower-like SnS catalyst confined by nitrogen-doped carbon (SnS@NC) and the CO₂ER performance of SnS@NC was studied. Based on the confinement effect of the ultra-thin nitrogen-doped carbon layer, the layer thickness of SnS nanosheet was reduced from the original 30nm to 20nm, and the electrochemically active area was significantly increased. At the same time, the nitrogen-doped carbon layer could enhance the adsorption and activation of CO₂. As a result, the CO₂-to-HCOOH conversion over SnS@NC was significantly enhanced. The SnS@NC provided an HCOOH Faraday efficiency of 81.2% at -1.3V(vs. RHE), and a current density up to 29.5mA/cm² in the H-type electrolytic cell. This work could provide a novel strategy for the functionalization of metal-sulfide based catalysts.

The development of CO₂ separation technologies with high efficiency and energy effectiveness has practical and long-term significance. Membrane based CO₂ separation has become a promising approach owing to its low energy consumption, easy operation, small footprint and cost effectiveness. Currently, the focus of membrane research is searching for novel membrane materials with excellent transport characteristics. Graphene and its derivatives have gained great attention in the field of gas separation because of the atomic thickness, sub-nano pore size and excellent mechanical, thermal and chemical stability. The limiting factors for the practical applications include the difficulties in processing, technological cost, large-area fabrication and membrane working stability. Graphene-based CO₂ separation membranes can be categorized as: nanoporous graphene, lamellar graphene oxide membranes and mixed matrix membranes with graphene and its derivatives as the nanofillers. The review summarized outstanding breakthroughs regarding graphene-based CO₂ separation membranes, emphasizing the gas transport mechanisms and structure-property relationships. Optimization strategies based on rational design and the underlying mechanisms discussed. Challenges analyzed and the potential research directions proposed. Systematic theoretical research should be conducted combined with advanced characterization methods to establish structure-property relationship of membranes. In addition, the cost-effectiveness and working stability vital for the practical applications.

As the exploration and development of oil and gas resources continue to develop into deep and ultra-deep reservoirs, conventional guar gum fracturing fluids cannot meet the needs of high temperature and ultra-high temperature reservoir fracturing operations. The researchers are committed to improving the temperature resistance of guar gum fracturing fluids from two directions: the temperature resistance modification of guar gum and the synthesis of new high temperature resistant crosslinking agents. Great progress has been made in the research on the damage mechanism of guar fracturing fluid to reservoirs. This paper reviewed the development trends of high temperature resistant guar gum fracturing fluids at home and abroad in recent years. The research status of the synthesis of high temperature resistant modified guar gum and high temperature resistant cross-linking agent was expounded. The damage types and damage mechanisms of guar gum fracturing fluid to reservoirs were summarized. The research progress of the damage mechanism of guar gum fracturing fluid to high temperature reservoirs was mainly analyzed. Finally, it was pointed out that the thermal resistance of guar gum should be further improved by chemical modification, and the research on gel breakers and nano crosslinkers should be strengthened. It was proposed that the nano crosslinking fracturing fluid with high efficiency and low damage was the possible development direction of high temperature resistant guar gum fracturing fluid in the future.

Superabsorbent materials have the advantages of high water absorption ratio, strong water retention capacity, soft appearance and porous network structure, but their absorption capacity to aqueous solutions containing electrolytes is limited. In this paper, the adsorption mechanism of superabsorbent materials was firstly analyzed. On this basis, the principle and characteristics of several common superabsorbent materials, such as superabsorbent resin, superabsorbent fiber, superabsorbent film and superabsorbent fabric-based aerogels were emphatically introduced. Then, the adsorption mechanism differences of these superabsorbent materials for deionized water, saline, synthetic urine and urea were summarized. It was pointed out that the liquid absorption capacity can be improved by increasing the specific surface area, the number of hydrophilic groups, molecular weight, appropriate degree of cross-linking and neutralization in combination with high osmotic pressure, electrostatic repulsion force and additional inorganic particles. Secondly, the application of superabsorbent fabric constructed by aerogels and textiles in the field of safety protection was briefly described. Finally, the growth point of superabsorbent materials was prospected. It was expected to provide theoretical reference and technical support for improving the absorption ability to aqueous solutions containing electrolytes of superabsorbent materials.

Biochar (BC) matrix with three-dimensional porous structure and large specific surface area (2136.67m²/g) was prepared by pyrolysis and KOH etching at 700℃ using corn straw as precursors. Afterward, a novel composite phase change materials (CPCMs) were fabricated via injecting stearic acid (SA) in BC supports where SA was mixed in ethanol, and then injected into BC scaffolds under vacuum. The prepared CPCMs were characterized by IR, XRD, SEM, TG and DSC methods. The results demonstrated that the CPCMs with a mass content of 71.2% possess well heat storage ability with a fusion enthalpy of 126.3J/g and a solidification enthalpy of 128.7J/g, respectively. This phase change enthalpy appeared a negligible change after 100 melting and freezing cycles, and no clear leakage was observed during the phase transition process, indicating that CPCMs were unique shape-stabilized phase change materials with excellent heat storage performance and reversibility. Besides, the fabricated CPCMs can be triggered by light irradiation or safe voltage (e.g., 5.0V) to fulfill electro- or photo-to-thermal conversion with 78.3% and 70.1% conversion efficiencies, respectively. With excellent energy transformation performance and ability of heat storage and releasing, the CPCMs were believed to have great potential values not only in heat storage but also in green and clean energy conversion and application.

Based on sodium acetate trihydrate (SAT), combined phase change materials were prepared by adding diatomaceous earth (DE) with microporous structure and disodium hydrogen phosphate dodecahydrate (DHPD) and other additives. Taking the subcooling temperature as the objective function and completing the double factor repeated measurement experiment, it could analyze whether nucleating agents had a significant effect on the improvement of undercooling characteristics of phase change materials, and could also study the interaction between nucleating agents. Different additives with various concentrations were combined into a mathematical super rectangle, which was divided into four partial super rectangles. The effects of different additives in a partial super rectangle on the supercooling characteristics of phase change materials were analyzed by orthogonal experiment. Combining the partial orthogonal experimental data, the overall analysis of variance was carried out to study the overall effect of different additives on the undercooling characteristics of phase change materials. Through multiple regression analysis of the overall experimental data, the mathematical model of subcooling characteristics was established to find the best scheme in line with the actual situation and the subcooling degree was less than 0.5℃. The better additive addition proportion under economic conditions were obtained. The composite phase change materials were prepared, and the properties of subcooling, latent heat and heat conduction were tested.

The dragonfly wing structure with excellent lightweight and high strength performance was taken as the design inspiration. On the basis of analyzing the impact resistance principle of the wing vein grid structure, the traditional and bionic structures were designed. Continuous carbon fiber reinforced polylactic acid (PLA) composites with different structures were successfully prepared by melt extrusion 3D printer, and the tensile and impact properties of the composites with different structures were tested and analyzed. The results showed that the improvement of the tensile strength of the biomimetic composite was limited by the relatively small content of continuous carbon fiber in the direction of tensile force, but the average tensile strength of the biomimetic composite was 1.18 times that of the traditional structure. When the biomimetic structure composite sample was subjected to impact force, the connection angle of hexagons inside it would change, which would greatly consume impact energy. Meanwhile, the continuous carbon fiber with hexagonal grid structure can effectively hinder the crack propagation, and thus the average impact toughness of biomimetic structure can reach 2.46 times that of traditional structure. Biomimetic dragonfly wing structure can significantly enhance the comprehensive mechanical properties of additive manufacturing composites, and improve the impact resistance of concrete outstanding effect. The effective and feasible structure design and additive manufacturing of continuous carbon fiber reinforced resin matrix composites can greatly expand their corresponding applications in the field of high impact loads.

LiNi_0.5Mn_1.5O₄(LNMO) is a promising cathode material for the next generation of high energy density lithium ion batteries. However, the serious manganese ion dissolution and rapid capacity degradation impede their practical application. Here, ternary spinel type high voltage cathode material LiNi_0.4Co_0.1Mn_1.5O₄(LNCMO) was synthesized by hydrothermal-calcination method. The calcination temperature and heating rate were optimized and investigated. The sample was uniform rhomboid-like morphology feature with pure structure. The specific surface area of the sample was 3.72m²/g and the average pore size was 11.60nm. The discharge voltage of LNCMO was close to 4.75V, and the initial specific capacity was about 143.90mAh/g, which was close to the theoretical specific capacity of LNCMO(146.70mAh/g). According to the XRD and XPS results, the proportion of Mn⁴⁺ was higher than that of Mn³⁺ in this sample. At the same time, appropriate calcination temperature and heating rate could avoid the formation of Li _x Ni_1-x O impurity phase, and thus the structural stability was higher, the charge transfer resistance was lower and the electrical performance was better of this sample. Comparing the XRD and SEM results of cathode materials before and after the cycle, the phase was basically the same, but the morphology and structure collapse was serious under high current density, which limited the cycle stability. This paper provided an effective strategy for preparing ternary high voltage materials for higher capacity and discharge voltage.

A new formulation for the preparation of phase change cold storage materials based on sodium sulfate decahydrate (SSD) was proposed for air-conditioning system applications, and all aspects of the material's performance were optimized. The nucleating agent ratio was first determined using the step-cooling curve method to eliminate subcooling of the material. On this basis, the effect of different types and levels of thickening agents [sodium polyacrylate (PAAS), polyacrylamide (PAM), carboxymethyl cellulose (CMC), polyanionic cellulose (PAC) and xanthan gum (XG)] on the phase separation and latent heat of phase change of the material was investigated and analyzed. Then, the melting point controller ammonium chloride and potassium chloride were added to change the phase change temperature of sodium sulfate decahydrate, and the phase change material was formulated to meet the air-conditioning temperature zone. Finally, expanded graphite (EG) was added to further improve the thermal conductivity and stability of the material, and the thermal cycling tests were carried out. The experimental results showed that the addition of 3% (mass fraction) borax was the most effective in reducing the subcooling of the material. The addition of 1.0%—2.0% (mass fraction) PAAS could eliminate the phase separation phenomenon of the material and had the less effect on the latent heat of phase change of the material. The material had a high thermal conductivity and shape stability when the mass ratio of SSD-BPA∶EG was 93∶7. The phase change temperature of the optimized composite phase change storage material was 7.4℃, the latent heat of phase change was 117.4J/g and the thermal conductivity was 1.876W/(m·K). The phase change temperature of the material remains stable after 200 cycles and the latent heat decay rate was 14.05%.

The novel technology of membrane separation, especially the two-dimensional lamellar membrane, holds broad application prospects in the separation field. However, the complex chemical environment and high cost of membrane nanomaterials currently limit their industrialization. Natural vermiculite has the advantages of cheap and easy to obtain, simple to exfoliationl, and only contains silica hydroxyl on the surface which is easy to adjust. Thus, the hydrophilicity and hydrophobicity of the as-prepared lamellar membrane can be precisely controlled to achieve efficient permeation of organic solvents and high separation of polar and non-polar solvents. The results indicated that the vermiculite lamellar membrane showed excellent molecular transport ability for polar solvents, while relatively low ability for non-polar solvents. The permeance of acetonitrile was up to 1650L/(m²·h·bar), while that of toluene was only 37.8L/(m²·h·bar). The separation factor of acetonitrile to toluene could be as high as 43.6, showing excellent molecular separation performance. The prepared vermiculite lamellar membrane with the interlayer spacing of 1.36nm held outstanding size sieving ability due to its regular and straight interlayer channels. The rejection of crystal violet (1.5nm), bright blue (1.6nm), acid yellow 14 (1.9nm) and other dye molecules with larger dynamics diameter than interlayer spacing were over 90%. Moreover, the vermiculite lamellar membrane displayed excellent pressure cycling stability and anti-pollution ability, showing great potential in separation applications.

A series of copolymers of mPEG₂₂-b-P[BnMA _x -co-L-ProlA _n ]-b-PDEA _y PBL-b-PD-(DEA) _m (m=0,1,2,3) with different content of CO₂-responsiveness diethylaminoethyl methacrylate (DEA) and mPEG₂₂-b-P(L-ProlA)-b-P[BnMA-co-PDEA] (PL-b-PBD) with different sequence structure were fabricated by reversible addition fragmentation chain transfer (RAFT) dispersion polymerization. The chemical structure and molecular weight distribution of the copolymers were carried out by ¹H nuclear magnetic resonance spectra (¹H ‍NMR spectra), X-ray photoelectron spectroscopy (XPS) and gel permeation chromatography (GPC). Dynamic light scattering (DLS) was used to investigate the self-assembly behavior of the copolymers and the CO₂-responsiveness of the nanoreactors. Moreover, dissipative particle dynamics (DPD) studies showed that the self-assemble structure of nanoreactors could be turned by controlling the monomer contents distribution and sequence structure of hydrophilic and hydrophobic. Finally, the nanoreactors were used to catalyze asymmetric Aldol reaction of cyclohexanone and 4-nitrobenzaldehyde in water. The results indicated that PBL-b-PD-(DEA)₂ gave the Aldol product with high conv., anti/syn and ee (96%, 97/3, 94%). This study provided a promising approach for exploring the self-assembly structure of copolymers on its catalytic performance.

In order to expand the application range of polyethylene terephthalate (PET), a third monomer is often introduced to change its properties. In this study, a series of copolyesters with different monomer contents were synthesized from spirocyclodiol (SPG) by transesterification melting polycondensation. Combining advanced polymer chromatography with multi-angle laser light scattering (APC-MALLS) was used to measure the molecular weight and molecular weight distribution. Meanwhile, the chemical structure of copolyester was studied by ¹H NMR and FTIR spectroscopy. The thermal and crystallization properties of copolyester were studied by DSC, TGA and XRD. The tensile properties of copolyesters were also tested. The results showed that the copolyester which met the number average molecular weight (M_n) and weight average molecular weight (M_w) requirements of fiber grade polyester was successfully synthesized with narrow molecular weight distribution. With the increase of the content of the third monomer, the glass transition temperature increased from 77℃ to 85℃, while the melting temperature decreased from 255℃ to 222℃. The thermal decomposition temperature did not change significantly and the crystallization property decreased.

Due to the prevalence of antibiotic resistance, novel antimicrobial materials have received increasing attention. Taking advantage of the unique structure and properties of halloysites (HNTs), HNTs-NaClO₂ composites were prepared by vacuum suction method using HNTs pretreated by alkali method as carriers. The structure and chemical composition of the composites were characterized by means of XRD, FTIR, TEM and EDS. TEM showed that the surface of the HNTs loaded with NaClO₂ had obvious crystals. The effects of different loading processes on the loading of NaClO₂ were explored, the release properties and bacteriostatic properties of HNTs-NaClO₂ were studied, and the biosafety of HNTs-NaClO₂ was investigated by acute oral toxicity experiments. The results showed that changing the stirring time and loading ratio of HNTs in saturated sodium chlorite solution could increase the loading of NaClO₂. When the stirring time was 2h, the loading was 4.91%, and when the loading ratio was 1∶4, the loading was 7.61%. On the 4th day, the release tended to be stable, and the content of sodium chlorite release was 1.43%. The antibacterial activity evaluation indicated that the composite material had inhibitory effects on Escherichia coli and Staphylococcus aureus. HNTs-NaClO₂ had inhibitory effects on male and female mice with LD₅₀ of greater than 5.00g/kg_BW. The HNTs-NaClO₂ composite material could be released stably and continuously, and had a certain antibacterial property, which belonged to the low toxicity level.

In view of the harm of leuco malachite green (LMG) to human health, it is important to establish a sensitive and rapid method for the detection of LMG residues in aquatic products. In this study, a novel molecularly imprinted electrochemical sensor (MIECS) for LMG detection was successfully prepared by the fusion of variety technologies, such as computer simulation technology, ultraviolet spectroscopy, self-assembled technique and electrochemical analysis technology. In the experiment, based on nanomaterial modified electrodes, LMG was used as the template molecule, and 4-aminophenol(4-ATP) was selected as the best functional monomer by the use of ultraviolet spectroscopy combined with computer simulation. The configuration, action forms and binding energies of the LMG and 4-ATP preassembly systems were simulated and calculated by using Gaussian 09. The morphology and chemical characterization of the membrane were characterized by scanning electron microscope and infrared spectrometer, and the imprinted effect and selection performance of the sensor were investigated by cyclic voltammetry and square-wave voltammetry. The sensor was applied for the rapid detection of food safety. The results showed that the template molecule and functional monomer mainly formed the LMG-2(4-ATP) complex through conjugation action. The sensor demonstrated good performance and could specifically recognize the LMG and its structural analogs. The linear response range of this method was 3.3×10^-11—1.0×10^-6mol/L with a good linear relationship, the detection limit was 1.0×10^-11mol/L, the spiked sample recoveries were between 85.5% and 101.2% and the relative standard deviations were 1.28%—2.48%. It was suitable for the sensitive and rapid detection of LMG residues in aquatic products. In the future, MIECS would be more sensitive, accurate, fast and miniaturized, and applied in more fields.

A bi-templates molecularly imprinted polymers (MIPs) was prepared by using tebuconazole (TBZ) and triadimefon (TDF) as co-templates, methacrylic acid (MAA) as the functional monomer, and ethylene glycol dimethacrylate (EGDMA) as the crosslinker with the molar ratio of templates to MAA and EGDMA of 1∶4∶20. The adsorption kinetics, static adsorption, and affinity site characteristics and selectivity of the MIPs were investigated. The results showed that the adsorption equilibrium of dynamic adsorption was reached within 2.5 hours, implying a rapid adsorption kinetics. Scatchard analysis indicated that there were two types of affinity sites in the MIPs, and the MIPs had a good group and specific selectivity for triazole fungicides. A molecularly imprinted solid phase extraction column (MISPE) was prepared with the MIPs as fillers for tobacco sample pretreatment, and MISPE-ultra-high performance liquid chromatography-tandem mass spectrometry method was established for detecting residues of tebuconazole, triadimefon, myclobutanol and triadimenol in tobacco leaves. The results showed that the MISPE column had good enrichment effect on tebuconazole, triadimefon, myclobutanol and triadimenol. The average recoveries were between 72% and 110.3%, and the relative standard deviations (RSD) were 2.38%—7.92%, (n=3). The method can easily and selectively realize accurate analysis of triazole fungicides residues in tobacco leaves.

Poly(methacrylate) (pMA)-grafted Sepharose FF with ionic capacity (IC) of 320mmol/L (FF-pMA-320) showed the high lysozyme and γ-globulin adsorption capacities, but its uptake rates for the two proteins were low. On the premise of maintaining polymer chain length, the charge density on pMA-grafted Sepharose FF was reduced by neutralization of the carboxyl groups on pMA chains with ethanolamine to improve protein uptake rate. FF-pMA-320 was partly neutralized to prepare the two charge-reduced cation exchangers with IC values (in mmol/L) of 230 and 170, which were respectively named as pMA-320-R230 and pMA-320-R170. Adsorption equilibrium, uptake kinetics and column breakthrough experiments were performed to study lysozyme and γ-globulin adsorption on to the two new resins, which were compared with the starting resin (FF-pMA-320). It was found that the adsorption capacities for the two proteins decreased with IC (charge density) decreasing from 320mmol/L to 170mmol/L, which was related to the decrease of adsorption site caused by the partial neutralization. With decreasing charge density of grafted polymer, there were weaker electrostatic repulsion between neighbouring polymer chains and lower protein adsorption capacity, thus increasing chain flexibility and reducing protein exclusion effect. Therefore, the uptake rates of lysozyme and γ-globulin on pMA-320-R170 were about 1.6 times and 5.5 times higher than those on FF-pMA-320, respectively. Column breakthrough results demonstrated that the dynamic binding capacity (DBC) of γ-globulin on pMA-320-R170 was higher than other two resins due to its high uptake rate, and kept over 10mg/mL in the flow rate range of 150—750cm/h. The findings in this work provided reference and direction to design and develop high-performance protein chromatography.

The structure of porcine pancreatic lipase (PPL) was selected as the research object, and betaine ionic liquids with different chain lengths and different anions were designed and synthesized as modifiers to chemically modify PPL. The protein concentration was determined by the BCA method, the degree of modification was determined by the trinitrobenzene sulfonic (TNBS) method, and the enzymatic activity was determined by the p-nitrophenol palmitate (p-NPP) method. The changes in enzymatic properties such as the optimum temperature, optimum pH, thermal stability, organic solvent tolerance and the kinetics of the native and modified PPLs were tested. Results showed that the chain length and anion of modifiers had a certain influence on the modification effect. The PPL modified by [BetaineC₁₆][H₂PO₄] presented the best enzymatic performance, the enzymatic activity of which was 3.4 times that of the native PPL, the enzymatic activity after stored at 60℃ for 45min was 8.7 times that of the native PPL, the stability was increased by 1.7 times after stored in strongly polar aprotic solvent dimethyl sulfoxide for 2h, and the selectivity of enantiomers in the catalytic reaction of α‍-phenyl ethanol was increased by 2.0 times. In addition, the temperature tolerance and pH tolerance of modified PPLs had been significantly improved. The kinetic test results also showed that modified PPLs had a higher substrate affinity so that it had higher activity. The results of fluorescence spectroscopy showed that the introduction of modifiers had a certain impact on the fluorescent group of PPLs. Fluorescence intensity decreased as the modification degree increased. The results of circular dichroism showed that the α-helix content of the modified PPLs decreased while the β-sheet content increased, which improved the activity and stability of PPLs. This experiment confirmed that betaine ionic liquids as modifiers could simultaneously improve various enzymatic properties of lipase, and expand a new type of modifier with good modification effects for chemical modification of enzymes.

3-Hydroxy-4-methoxy cinnamaldehyde is an important intermediate for the preparation of advantame, which is a novel dipeptide sweetener with super-high potency. At present, this intermediate is mainly synthesized by Aldol condensation reaction of isovanillin and acetaldehyde in the presence of strong base. However, since acetaldehyde is prone to self-condensation, there are problems such as harsh reaction conditions and low yield of 3-hydroxy-4-methoxy cinnamaldehyde. In this paper, a new process for preparation of 3-hydroxy-4-methoxy cinnamaldehyde by using vinyl acetate as a reactant in place of acetaldehyde to react with isovanillin was studied. The influences of reaction temperature, reaction time, NaOH dosage and molar ratio of isovanillin to vinyl acetate on the reaction were investigated by single factor experiments. On the basis of the single factor experiments, the response surface optimization was carried out. Results showed that the yield of 3-hydroxy-4-methoxy cinnamaldehyde was 71.44%±2.21% under optimal conditions: NaOH concentration of 4.5mol/L, reaction temperature of 10℃, reaction time of 12h and the molar ratio of isovanillin to vinyl acetate of 1∶2. In order to further improve the product yield, the strengthening effect of adding a phase transfer catalyst to the reaction system was explored. It was found that PEG-200 had a significant catalytic effect on the reaction, and the yield of 3-hydroxy-4-methoxy cinnamaldehyde achieved 83.12%±2.18%.

Rosin-based fluorescent waterborne polyurethane emulsion (FWPU) with good stability was successfully prepared using isophorone diisocyanate (IPDI), ester (RAG) of acrylic rosin adduct and 2-hydroxyethyl methacrylate as raw materials, dihydroxymethyl propyl acid (DMPA) as hydrophilic chain extender and 5,7-dihydroxy-4-methyl coumarin (DHMC) as fluorescent chain extender. The structure of FWPU was characterized by ¹H NMR, Infrared spectrum and UV-visible spectroscopy, and the effects of the amount of DHMC and quenching agent 1,4-hydroquinone (HQ) on the fluorescence performance of FWPU were discussed. The UV protection performance (UPF) of polyurethane film was tested. The results showed that DHMC was successfully linked onto the polyurethane main chain. With the increase of the dosage of DHMC, the fluorescence intensity of FWPU increased gradually, and the maximum fluorescence intensity was 5002 when the dosage was 1%. Compared with DHMC, the fluorescence intensity of FWPU increased significantly. The fluorescence quenching effect of HQ on FWPU was obvious. With the addition of DHMC, the UPF value of polyurethane increased from 6.86 to 12.27, and the UV protection performance was improved as well as the water resistance.

The degradation of phenolic pollutants by activated persulfate (PS) has attracted much attention due to its economical, efficient, environmentally friendly, safe and stable advantages. Presently, there are two main activated methods for PS such as external energy and catalyst activation. The single external energy activation for PS which contains heat, light, ultrasound, electrode and plasma activation, etc. exhausts more energy but gains poor degradation effect of phenolic pollutants. More and more researchers begin to focus on external catalyst activation of PS owing to its little environmental pollution, low operation cost and high degradation efficiency. In order to increase the degradation efficiency of phenolic pollutants, different activation methods of PS gradually have mixed together and they finally have brought about hybrid technologies such as combination of carbon materials and transition metals, combination of electrode and transition metals, and combination of light and catalysts. The research progress on degradation of phenolic pollutants by activated PS were reviewed systematically. Then, the influencing factors of activated PS were sketched. Furthermore, the existing problems of degradation of phenolic pollutants by activated PS were analyzed. Finally, the development trends of degradation of phenolic pollutants by activated PS were forecasted.

The interactive migration and transformation pathways of microplastics in the environment mainly include that microplastics enter the sea with water flow first and then suspend in the air with air currents due to the properties of lightness and small size. Ultimately, the suspended microplastics accumulate in soil or sediment, which might be ingested by plants or animals or even humans. Therefore, the hazard index of microplastics was calculated using the pollution load index and the potential ecological risk index to evaluate the level and evolution trend of environmental risk posed by microplastics in this paper. So far, the potential risk of microplastics was within an acceptable range, while this value would increase to the limitation value of national standard within 80 years if this uncontrolled plastic utilization still extended. Therefore, the reduction of plastics production might be an effective approach to control microplastics due to technical limitations on intensively and effectively removal of microplastics and decompose and metabolize microplastics in the environment. At the same time, since people's cognition of microplastics was still in its infancy, it was the current primary task to deeply understand the combined effects of microplastics and pollutants and their destructive effects on the ecological environment, and to improve the microplastics risk assessment model.

The traditional method of extracting copper from qualified chalcopyrite mainly adopts pyrometallurgical process. With the continuous exploitation and utilization of copper bearing minerals, the high-quality chalcopyrite decreases day by day. It is more and more difficult to extract copper economically and efficiently from low-grade chalcopyrite by traditional pyrometallurgy, and the pyrometallurgy process will produce a lot of gases such as SO₂ which are harmful to the environment and human body. Compared to pyrometallurgical process, the extraction of copper from chalcopyrite by hydrometallurgical process has the advantages of low energy consumption and environmental friendliness, especially suitable for the treatment of low-grade complex polymetallic chalcopyrite. However, the hydrometallurgical process has the problem of low leaching efficiency. In this paper, the research status of improving hydrometallurgical leaching efficiency of chalcopyrite in recent years is reviewed and analyzed. The analysis showes that the methods of enhancing leaching efficiency of chalcopyrite can be divided into pre-activation before leaching and strengthening during leaching. Pretreatment activation includes mechanical activation, thermal activation and microwave activation, which can improve the reactivity of chalcopyrite during leaching. The strengthening in the process of leaching included adding pyrite, Ag ion, activated carbon and other additives to strengthen the leaching, and using ultrasonic field, microwave field and pressure field to strengthen the external field. Based on the research results of strengthening process, the mechanism of various strengthening processes and methods are analyzed, the advantages, disadvantages and existing problems of various strengthening methods are compared, and the development direction of strengthening leaching of chalcopyrite is forecasted. The results indicate that both pretreatment and leaching process strengthening can effectively improve the leaching efficiency of chalcopyrite, and the process combining pretreatment activation and process strengthening is an effective method to enhance the leaching efficiency of chalcopyrite.

In order to realize simultaneous nitrification and denitrification phosphorus removal turn to short-cut nitrification and denitrification phosphorus removal, taking the particles as the inoculated sludge, the granular sludge was domesticated by using the artificial water distribution with low C/N ratio and the alternating strategy of low/high aeration intensity under long or short hydraulic retention time (HRT). This strategy could maintain higher FNA concentration and duration, inhibit phosphate accumulating organisms (PAOs) and enrich denitrifying phosphate accumulating organisms (DPAOs) at the same time. In addition, the difference of oxygen affinity between AOB and NOB was used to produce nitrous accumulation, providing electron acceptor for DPAOs, and finally, realize shortcut nitrification and denitrification phosphorus removal. The results showed that the proportion of \mathrm{N}{\mathrm{O}}_{\mathrm{2}}^{-}-DPAOs in granular sludge with low/high aeration strategy was 45% and the activity of NOB decreased to 3.28mgN/(gMLVSS·h) on the 60th day. In the treatment of low-carbon source wastewater, the low/high aeration intensity mode showed stronger adaptability and stability than the constant aeration intensity mode. In the stable period, the effluent COD concentration was less than 50mg/L, the effluent TN and total phosphorus (TP) concentrations were less than 15mg/L and 0.5mg/L, respectively. The TN removal rate was 94.54% and the average TP removal rate was 96.90%.

In order to realize the recycling and value-added utilization of carbon-containing components in food waste, the self-made nano-CaO₂ was used as an oxidant to stimulate the release of carbon components in food waste with urea as a modifier, acrylamide as a monomer, N,N'-methylenebisacrylamide as a crosslinking agent and sodium persulfate as an initiator. The food hydrogel was synthesized by free radical polymerization crosslinking reaction, and the swelling properties of the prepared hydrogel were analyzed. The influencing factors of hydrogel preparation were investigated by single factor experiments. The results showed that the swelling rate of hydrogel could reach 1429.78% with oxidant dosage of 0.70g, modifier dosage of 4.60g, monomer dosage of 2.80g, crosslinking agent dosage of 0.14g and initiator dosage of 0.38g. The swelling behavior of the hydrogel in deionized water at 0—12h conformed to Fickian's Case I diffusion, and the swelling behavior at 12—84h was to Schott's second-order model of swelling kinetics. Microscopic characterization proved that the swelling was related to the network structure of the hydrogel. Thermogravimetric analysis indicated that the hydrogel prepared from food waste had good thermal stability.

Previous studies have found that the iron-manganese oxide film (MeO _x ) has a high removal efficiency for ammonium, iron and manganese in water, but the removal efficiency of organic matter (in COD_Mn) is poor. To improve the removal efficiency of MeO _x for COD_Mn, the potassium ferrate was used to strengthen the catalytic oxidation process of MeO _x, and its effective removal of COD_Mn and some influencing factors were explored in this study. The experimental results were showed that when only 0.1mg/L of potassium ferrate was added into the influent, the removal efficiency could be about 92.5% for 20mg/L COD_Mn in the influent. The filtration rate (v) had a certain influence on the removal of COD_Mn. The removal efficiency of COD_Mn would gradually decrease with increasing filtration rate, and the concentration of COD_Mn in the effluent could be 3.0mg/L (v=6—10m/h). When the filtration rate reached 11m/h, the removal efficiency of COD_Mn would reduce to 81.65%. The lower pH (about 6.51) had certain adverse effect, and the removal efficiency of COD_Mn would gradually decrease with the decrease of pH. The NH₄⁺ in the influent would also affect the removal of COD_Mn, and the higher the concentration of NH₄⁺, the lower the removal efficiency for COD_Mn. Scanning electron microscope (SEM) results indicated that some brown substances was formed on the surface of MeO _x after ferric acid-base enhanced filtration for about 60 days. The surface of MeO _x was analyzed by electron energy dispersive spectrometer (EDS). It was found that the proportion of C and O elements were increased and that of Mn and Fe elements were decreased significantly, but the reduced Fe and Mn species did not affect the removal of COD_Mn. X-ray photoelectron spectroscopy (XPS) analysis showed that the compounds corresponding to Mn elements were MnO, Mn₂O₃ and Mn₃O₄ before and after enhanced filtration, and the substances on the surface of MeO _x for C and O elements was (CH₂)₄O_n .

Aiming at the NO _x removal efficiency and microbial community structure change of chemical absorption-biological reduction integrated system (CABR) cooperated with the adjusting NO _x oxidation ratio under different oxygen volume frations, the effect mechanism of oxygen on the CABR system was studied. Results showed that when the NO _x oxidation ratio in the simulated flue gas was adjusted to 50% and the oxygen volume fration in the flue gas was in the range of 0—8%, the NO _x removal efficiency of CABR system was stable above 99%. When the oxygen volume fration reached 10%, the denitration efficiency of the system could still exceed 94%. The detection of EPS content showed that when the oxygen volume fration increased from 0 to 5%, the PN/PS value in LB-EPS increased from 1.72 to 2.18, and the PN/PS value in TB-EPS decreased from 1.21 to 0.706. High-throughput sequencing results indicated that Proteobacteria was the dominant phylum under different oxygen volume frations, and its relative abundance reached 55.0%—85.7%. Proteobacteria was a typical phylum with aerobic denitrification capacity, which ensured the stability of denitration performance of the system. In conclusion, the oxygen volume fration had little influence on the denitration effect of the CABR method cooperated with adjusting NO _x oxidation ratio, which provided a new idea for the removal of NO _x in the flue gas.

Oily sludge is widely produced in the process of petroleum exploitation, refining and application. The resource utilization and harmless treatment of oily sludge has always been a problem in the industry. Taking the heavy oily sludge residue after traditional water washing treatment as an example, this paper systematically studied oxidative degradation law and process enhancement mechanism of it using peroxymonosulfate-ferrate-FeS (PFI) oxidation system. The results showed that the PFI oxidation system could degrade oily sludge residue containing heavy oil components such as resins and asphaltenes and converted large-molecule organics into small-molecule organics. However, due to the adsorption of sludge solid particles in porous pores and other reasons, some heavy components would remain in the pores and were difficult to degrade. In addition, after PFI oxidation of oily sludge, the resulting solid surface would be covered with a thin layer of secondary product iron oxide, which prevented the oxidant molecules from further contacting the petroleum molecules, thereby reducing the oxidation effect or even stopping the oxidation process. The surface acidity control method could greatly dissolve the thin iron oxide layer to increase the chance of contact between the oxidant and the organic matter, thereby enhancing the degradation rate of the residual heavy oil organic matter.

As a non pressure driven membrane desalination technology, forward osmosis has the advantages of low energy consumption, light membrane pollution and high water recovery. In this paper, the strategy of desalting using diamine (TEPDA, N,N,N',N'- tetraethyl-1,3-propanediamine) switchable solvent through protonation decarbonization reversible cycle as forward osmosis extraction solution was proposed. Firstly, TEST software was used to predict that compared with traditional organic solvents and monoamine solvents (such as DMCHA, N,N-dimethyl cyclohexyl amine), TEPDA had lower volatility, higher safety and lower reproductive toxicity. The results of forward osmosis experiment showed that the reverse flux selectivity of TEPDA was higher than that of DMCHA in both modes, which proved that TEPDA had better forward osmosis effect. At the same time, the effect of TEPDA in PRO mode was better than that in FO mode. The optimal operating temperature of TEPDA was 30℃ and the optimal flow rate was 500mL/min. Under the optimal conditions, the 1% (mass ratio) sodium chloride solution was operated for 5h. It was found that the TEPDA could still maintain the forward permeation flux of 6.09L/(m²·h) after 5h, which had the stability of continuous operation. The cycle experiment also proved that TEPDA had good cycle stability. The above results provided a basic theoretical guidance for the application of diamine (TEPDA) switchable solvent in the field of forward osmosis desalination.

Reducing CO₂ emissions is particularly important for environmental protection. In conventional Rectisol process, a large amount of CO₂, absorbed by poor methanol, is diluted by N₂ and directly discharged into the atmosphere as tail gas. In order to explore the space for process improvement, a conventional Rectisol process was simulated based on Aspen Plus. The physical property method selected the CPA (Cubic-Plus-Association) model, and the binary interaction coefficient of the model was corrected, and then compared with the practical data to ensure the accuracy of the model. For process improvement, firstly, the first improvement, based on the conventional Rectisol process, was proposed by combining four-stage pressurized hot flash and depressurized flash for CO₂ capture, and the related parameters were optimized to further reduce the system utilities consumption. The result showed that although the CO₂ production of the first improvement process was 3.3 times that of the conventional process, the system energy consumption increased by 2.12%, and the system exergy consumption increased by 17.81%. Next, further energy saving improvement was made on the basis of the first improvement process by adopting the combined technology of "semi-lean solution + turbine recovery". The CO₂ production of the second improvement process was not only equivalent to the first improvement process, but also the system energy consumption and exergy consumption reduce by 17.16% and 5.85% respectively compared with the conventional Rectisol process.

Complex wet denitrification by Fe^ⅡEDTA is a promising process to remove nitric oxide (NO) from flue gas, in which the desorption of NO from Fe^ⅡEDTA-NO solution is of great importance for the reuse of Fe^ⅡEDTA solution. In this paper, vacuum desorption technology was first employed for denitrification system of mixed Fe^ⅡEDTA and ascorbic acid (VC). The effect of operating factors including vacuum degree and temperature on NO desorption performance was thoroughly investigated in a lab-scale reactor. The experimental results showed NO could be desorbed from Fe^ⅡEDTA-NO rich solution by direct heating or vacuum, and the increase of vacuum degree and temperature could significantly improve the desorption performance. In addition, compared with direct heating regeneration, vacuum desorption could improve desorption rate and lower the total energy consumption. The kinetics study showed that the desorption process presented first-order kinetics regarding Fe^ⅡEDTA-NO. Meanwhile, the activation energy, activation entropy, and activation enthalpy of Fe^ⅡEDTA-NO desorption were calculated to be 2.83kJ/mol, 196.90J/(K·mol), and 159.76kJ/mol, respectively. Finally, the absorption-desorption recycling experiments showed that Fe^ⅡEDTA-NO rich solution, after vacuum desorption of NO, could continue to capture NO, while the average NO removal efficiency would decrease below 90% after 11 cycles.

The effects of organic base triethylamine (Et₃N) and inorganic base NaOH on the liquid-phase hydrodechlorination (HDC) of 2,4-chlorophenol (2,4-DCP) over Pd/C catalyst in different solvent systems were studied. The results showed that efficient HDC of 2,‍4-DCP could be achieved in methanol and ethanol with Et₃N as the proton scavenger. Meanwhile, the reaction mechanism was studied through catalyst characterization (SEM, XRD, and XPS). It was found that the byproduct HCl could be efficiently eliminated by generating Et₃N·HCl with Et₃N in methanol, which prevented the catalyst poisoning caused by HCl. Moreover, the high solubility of Et₃N·HCl in methanol prevented inorganic salts from depositing on the surface of catalyst and thereby avoided the decline in the activity and stability of the catalyst. Furthermore, the effects of different types of organic amines on the HDC rate and the selectivity of 2,4-DCP over Pd/C catalyst in methanol were investigated. Compared to long-chain organic amines, short-chain organic amines (primary amines, secondary amines, and tertiary amines) were more favorable. Based on these studies, a novel Pd/C-methanol-short-chain organic amine catalytic system was established for the efficient HDC of pollutants containing high concentration polychlorinated phenols. Thus, this study provided a vital guidance for realizing the environmentally friendly and harmless HDC treatment of the pollutants with high concentration polychlorinated phenols under mild conditions.

The essence of China's rural revitalization is the basis of producing the cereal, at the same time, integrated the processing, ecological environment and green energy. While, from the perspective of space, the essential difference between the industrial park and the agricultural park is that the agricultural industry has low capital bearing density and poor efficiency. So, it is necessary to learn from successful foreign experience, such as high-tech agriculture in the Netherlands and Israel, rural industrial parks led by Japanese and South Korean policies, and the bioenergy fund-driven channel model in the United States and Germany. However, China is a big country with a large population. In order to ensure food security, China's national policy for rural revitalization must be the basis of agricultural planting. Integrating China's world-leading photovoltaic and wind power technology, as the first-mover and institutional advantages in the early post-industrial era, the incubating and exploring rural industrial parks integrating agricultural planting, ecological environment, green energy and processing in such areas, and at the same time, supplemented by the cooperation with the national bioenergy product stimulation fund with the similar household registration policies will be promoted, so as to find a way of rural revitalization suitable for China's conditions.