With the rapid development of the new energy industry, lithium is widely used because of its high energy density, extracting lithium from salt lake brine is an important way to obtain lithium resources. The main methods of extracting lithium from salt lake brine are carbonization, precipitation, ion-sieve adsorption, and electrochemical method. Ion sieve adsorption method is suitable for selective recovery of lithium from low concentration liquid phase. Titanium-based lithium ion sieve has become a research hotspot because of its strong stability and large adsorption capacity. Based on the titanium-based lithium ion sieve technology, this paper analyzes the global lithium resource distribution and the lithium extraction mechanism of titanium-based lithium ion sieve, and summarizes the synthesis methods, molding methods and existing problems of titanium-based lithium ion sieve, so as to provide reference for the subsequent development of new titanium lithium ion sieve and the improvement of saturated adsorption capacity.

The flow channels of printed circuit heat exchanger (PCHE) are formed by chemical etching on metal plates. Diffusion bonding technology is also applied to manufacturing heat exchange cores which are assembled by those metal plates with flow channels. Compared with traditional heat exchangers, PCHE has many advantages such as high efficiency, compact structure, high temperature and pressure resistance. It is widely used in unclear plants, solar power systems, hydrogen production systems and gas turbines. In order to further improve the comprehensive thermal-hydraulic performance of PCHE and expand its application in industrial, the present work comprehensively summarizes the evaluation criteria, structural optimization status and related industrial applications of PCHE. At the same time, through reviewing relevant research at home and abroad, the future the focus of optimization research in the future and application potential of PCHE are prospected, which provides reference for structural design and performance improvement of PCHE.

Heat pump distillation is applied to the heat combination between the diesel hydrogenation unit and dry gas concentration unit in a refinery. The medium-water is used to absorb the heat of the gaseous oil at the top of the product fractionator of the diesel hydrogenation unit. After the medium-water is vaporized and pressurized for temperature raising, it is sent to the C₄ absorption tower reboiler and C₄ desorption tower reboiler of the dry gas concentration unit, so as to save the steam. Through optimization, the temperature of the gaseous oil at the top of the fractionator after heat exchange is controlled to 130℃, the pressure of the steam after compression is 278.4kPa, and the compression ratio is 1.43. And the process of double flash tank is innovatively adopted to avoid using water cooler to cool medium-water, which can save 20t/h circulating water and recover 0.2t/h steam. The heat in the diesel hydrogenation unit was recovered by 6.93MW, and the steam was saved by 11.5t/h. The annual operation cost is saved by 7.652×10⁶CNY compared with the original system, and the energy-saving benefit is 50.66%; the annual energy consumption is saved by 4944.0t EO, and the energy saving amount reaches 70.93%.

Ethylene oxide (EO) is an important petrochemical product. This product is flammable and explosive, and it is also a toxic carcinogen. In Shandong province, a chemical plant's EO production equipment has qualified T-shaped piping materials and welds, and the medium in the pipe is non-corrosive, but frequent cracks cause the medium to leak. The reason for the failure of the T-shaped tee crack is unknown, causing the plant to replace the T-shaped tee almost every six months pipe fittings caused serious economic losses to the plant. In order to solve the frequently failure of the T-shaped tee at the plant, the cause of the T-shaped tee failure must be accurately identified. Therefore, identifying the failure mechanism of the T-shaped tee becomes the key to solving the problem. This paper uses flow field analysis software, combined with the on-site fault condition of the three-way pipeline, to analyze the internal flow field characteristics and the failure mechanism of the T-shaped three-way device. There are two symmetrical vortices in the internal flow field of the T-shaped three-way device, which results in unstable flow velocity and pressure distribution of the T-shaped three-way flow field. A low-pressure zone with a large range below the vaporization pressure is formed. The liquid vaporizes to form a large number of bubbles, and the bubbles rupture on the inner wall of the tee creates a huge pressure shock, causing cavitation corrosion and damage, and causing the T-shaped tee of the lean water pipeline to crack. Therefore, three improvement schemes are proposed, use Y-shaped tee, arc tee and arc-shaped shaped tee structure instead of T-shaped tee structure, and analyze the flow field characteristics of three tee structures. Numerical calculation results show that the proposed three-way structure can greatly reduce the cavitation damage of the three-way pipe. Among them, the Y-shaped tee has a weak fluid vortex, which produces the smallest volume in the low pressure zone, but the inlet direction changes, not easy to transform; The arc-shaped three-way structure does not change the original inlet direction, the flow field pressure and velocity distribution are more stable, and the flow field characteristics are better than the Y-shaped three-way; Although the absolute pressure of the spherical three-way flow field is higher than that of the Y-shaped and the arc-shaped shaped, the structural outlet and the downstream flow field pressure are the most stable. This article provides a new idea for solving T-shaped tee crack failure and provides guarantee for the safe and effective operation of tee fittings in chemical plants.

HVAC&R(heating, ventilation, air conditioning & refrigerating) systems with hybrid energy sources need to transfer heat among three or more fluids. Three-fluid heat exchanger has application potential in this field and its optimization shows great significance. For three-fluid heat exchangers with phase change, existing definition of thermal resistance does not work well while the recent developed entransy theory offers an alternative way. In this paper, a fin-tube three-fluid heat exchanger is simulated with distributed parameter method and validated by experimental results. Entransy-dissipation-based thermal resistance for three-fluid heat exchanger with phase change is derived. The performance of different structures and air flow rate is analyzed on the basis of both heat transfer rate and entransy theory. The results show that using entransy-dissipation-based thermal resistance as the criterion achieves different results with maximizing heat transfer rate when circuit arrangement type is varied, while same results when tube diameter or air flow rate is varied. Optimal circuit arrangement is obtained by using entransy-dissipation-based thermal resistance as criterion, which can take heat transfer matching between different sides and pressure drop into consideration. This paper provides useful results on the optimization of three-fluid heat exchangers in HVAC&R systems and a new application field of entransy theory.

Through to the mixer of the selection of each component analysis and introduction, aiming at 10 in the desulfurization denitration common specifications of the limestone slurry tank, mixer technology selection on the optimization design, analyses how to do in the desulfurization denitration limestone slurry tank mixer optimization selection, so as to achieve the optimal land use effect and the technological requirement. At present, the selection of mixer and the design of its internal components are largely dependent on experiment and practical engineering experience. The advantages and disadvantages of product design can make the benefit of mixing equipment is very different, so on the basis of clear limestone slurry material properties, for each element of mixing equipment, such as the shape of the impeller, impeller diameter, layout layer number, speed, mixing shaft size, baffle size and number of one optimization. By making full use of the comparative analysis of existing achievements, the design and selection of ten common specifications and models of limestone grout box are optimized, so that the design theory of mechanical mixer is more perfect, and it can also meet the requirements of practitioners in the daily desulfurization and denitration industry on the selection of limestone grout box mixer.

A new technology of frozen seawater desalination for agricultural irrigation and livestock drinking water is introduced. Currently, liquefied natural gas (LNG) production capacity has reached 290 million tons/year. The huge cold energy released from the regasification process of LNG can be used in the freezing desalination process to minimize the total energy consumption. The FD process of ice sheet machine using LNG cold energy was designed and simulated by using HYSYS software. The ice making bucket of the ice sheet machine is used as the sea water crystallizer mainly because it has no heat source for continuous ice making and deicing. The dynamic model of the frozen section is established and simulated by gPROMS software. The results show that about 1.9—2.1kg of ice melt water can be obtained with 1kg equivalent of LNG cold energy. The results show that the energy consumption of the hybrid process is negligible (3.725Wh/100kg).

Using the deionized-water as the working fluid, both single-phase and two-phase heat dissipation systems for copper foams were designed. For low Re number, the copper foam sample with 80% porosity and 90PPI presented the maximum heat transfer coefficient, while for large Re number, the copper foam sample with 80% porosity and 45PPI outweighed. The copper foam sample could show six times larger than the bare channel in heat transfer coefficient, but consume more pump power. For the two-phase heat transfer, experiments found that low porosity samples (70%~80%) could effectively reduce the wall superheat and enhance boiling heat transfer. Porosity plays a more important role than pore density. Larger pore density would be helpful to provide more nucleation site density and larger capillary force. The samples with 90PPI have better heat transfer performance in flow boiling process.

Traditional data-driven process monitoring methods mainly ignore the consideration of process mechanism. The predictive residuals-based process monitoring methods realize the approximation of the local process mechanism by a data-driven regression model, and use the residual of the regression model as a feature to better monitor the abnormal deviation of the process. But their approximation of the local process mechanism ignores the specific process information. As a form of process information, process topology can be used to extract the process and causal relationship between variables. Based on this, a statistical process monitoring method based on process topology information is proposed in this paper. Considering specific process information, a modified index for variable selection is proposed by extracting the process and causal relationship between variables from the flowchart. On this basis, a process monitoring model based on prediction residuals is established to monitor the process deviation. The proposed method combines specific process information with a data-driven regression model to achieve a more accurate approximation of the local process mechanism. The proposed method is applied to a continuous reforming unit, the result shows that the method proposed in this paper can detect fault earlier compared to process monitoring method based on prediction residual or PCA (principal component analysis) model.

Low-temperature Fischer-Tropsch (LTFT) synthesis technology has attracted much attention in the coal chemical industry owe to its advantages of good product quality, low reaction energy consumption, large production capacity and more selectable catalysts species. Wax oil obtained from low-temperature Fischer-Tropsch synthesis can be refined to obtain high-quality clean oil by hydrocracking process. In this work, the product characteristics of Fischer-Tropsch synthesis was described, the reaction characteristics of wax oil hydrocracking, the reaction progress of wax oil and the carbocation reaction mechanism of the bi-functional catalyst in the hydrocracking process were listed and analyzed. Recent advances in hydrocracking bi-functional catalyst for wax oil hydrocracking have been emphatically introduced. Besides, the influence of active metal components, supports and additives on the hydrocracking process were also discussed. The analysis shows that the loading of active metals, the acid content and pore structure of the carrier have a great influence on the catalytic performance. The key of improving the activity of hydrocracking catalysts is the optimization and reasonable matching between the active sites of hydrogenation metal and the acid sites of cracking. In addition, the integration of composite-multi-model pores and active sites undoubtedly improve the product distribution and product property of wax oil hydrocracking based on the shape selectivity of zeolite.

Hydrate-based technology has great potentials in the fields of gas separation, gas storage, seawater desalination, cold storage and so on. The investigations of hydrate growth behaviors and hydrate morphology characteristics are necessary for the increase of hydrate gas storage capacity, the reduction of the risk of natural gas hydrate exploitation and the prevention of the pipe blockage caused by hydrate. This paper systematically reviews the researches of hydrate morphology from three aspects which are classified based on the size of hydrate: the hydrate lattice structure at nano scale, the hydrate crystal morphology at millimeter scale and the hydrate growth morphology at centimeter scale. This paper summarizes the lattice structures of the different hydrates formed by different guest molecules. This paper summarizes the effects of supercooling and liquid phase composition on the crystal morphology of clathrate hydrate and semi-clathrate hydrate. The growth behavior and the effects of the influential factors on hydrate growth morphology are introduced from four aspects: the heat transfer at the metal surface, the mass transfer at the interfaces between different phases, the effect of crystal nuclei and the effects of different promoters. This paper summarizes the promotion of the studies on hydrate morphology that lay a foundation for industrial application of hydrate-based technology, and provides a guidance for the further study on hydrate morphology.

The development and application of proton exchange membrane fuel cells is one of the most important pathways to realize the low-carbon emission and environmental protection for modern lifestyle. Membrane electrode assembly (MEA) is the core component for proton exchange membrane fuel cells. The ordered structure for membrane electrode assembly is the key to simultaneously meet the low Pt loading and high electrochemical activity. In this paper, the recent research progress of MEAs for PEMFC is systematically summarized. Compared with the less progress of the strategy to enable ordered proton conductor, the structural optimization realized by ordered catalyst and ordered catalyst carrier have shown great progress in developing better MEAs, demonstrating the significant potential for massive application of proton exchange membrane fuel cells.

Gas chromatography with microwave-induced plasma atomic emission detection(GC-AED) is a distinctive analytical instrument, which has both chromatographic separation ability and high sensitivity for element detection. It is widely used in many fields and can be used as a powerful analytical instrument for nitrogen compounds in oil products. The research progress of GC-AED is reviewed from three aspects: instrument composition, detection principle and characteristics, with emphasis on the application of equal molar response and element proportional inference. The research status of two nitrogen detection channels (174nm and 388nm) is compared, and it is found that there is equal molar response and higher selectivity at 388nm; at present, the detection of nitrogen compounds by GC-AED is mainly at 388nm, the factors affecting the detection of nitrogen compounds in oil products by 388nm are reviewed, and a set of suitable gas conditions are sorted out to achieve compound independent correction, which can be used for quantitative analysis. The application prospect of GC-AED analytical technology is prospected, and its application field is expected to be expanded with other analytical instruments.

Proton exchange membrane fuel cell electric vehicles have the advantages of long cruising range and environmental-friendly, but there are problems in starting difficulties or even failures in low temperature environments. This problem seriously restricts the development of proton exchange membrane fuel cell electric vehicles.The study investigated the principle of icing inside the proton exchange membrane, and briefly described the damage to the proton exchange membrane itself, the catalytic layer, the gas diffusion layer and the membrane electrode as a whole by the start-up process in the sub-zero temperature environment. It focuses on the analysis of low-temperature start strategies for proton exchange membrane fuel cell electric vehicles, which can be roughly divided into three categories: shutdown and purge control strategies, external auxiliary heating and no auxiliary heating. The analysis shows that each method has its own advantages and disadvantages, but in general, a single starting method is not enough for the low-temperature starting effect of proton exchange membrane fuel cell electric vehicles. The mixed use of multiple methods has an ideal effect. In the future, the low-temperature start-up technology of fuel cell electric vehicles will develop towards a trend of mutual assistance in a variety of ways.

The solid oxide electrolysis cell (SOEC) is an advanced electrochemical energy conversion device characterized by high efficiency, simplicity, high flexibility, and environmental friendliness. Thus, it has been a research hotspot in the energy field internationally. However, the SOEC operates in a complex environment (high temperature, closed, etc.), and experimental research is expensive, some cannot even be completed. Comparatively, numerical simulation has the advantages of low cost and easy operation. In recent years, the modelling and simulation of SOEC for hydrogen production has made great progress. The working principle of SOEC were briefly introduced first. The fundamental theories i.e., electrochemistry, thermodynamics, and fluid dynamics, were then elaborated. The progress in simulation technology were summarized from the perspectives of steady and transient state, system, macro-and micro-level. The limitations of current research were also pointed out to provide useful reference for further development of the technology. More research work should be emphasized on model verification, applicability analysis, non-design working and dynamic operating characteristics. With the continuous improvement of simulation technique, it will provide significant support for the commercialization of SOEC technology.

The yield of slurry oil from FCC unit is usually more than 5%. It is necessary to eliminate solid particles from them for integrated utilization. The decant oil can be directly mixed into the feedstock of some heavy oil processes including delayed coking, solvent deasphalting, asphalt blending, hydrocracking and so on. But the added value of them is low. The current researches about the decant oil focus on component separation through the processes including vacuum distillation, solvent extraction, supercritical fluid extraction and so on. The high-value components from the processes, especially intermediate aromatic component, can be deeply processed into needle coke, environmental friendly rubber filling oil, asphalt resin, carbon fiber and so on. Supercritical fluid extraction can separate the slurry oil at a lower temperature so as to avoid mass destruction of component by distillation with high temperature. Therefore, supercritical fluid extraction is becoming the host research field for producing needle coke. The process of delayed coking is usually used to produce needle coke. Low speed, low temperature and long residence time are required in the early stage of reaction. But it is necessary to raise temperature at later stage for engendering traction on needle coke by masses of airflow which is produced in the reaction. There is still a big gap in product quality between China and foreign countries. The PCA and eight kinds of PAHs of environmental friendly rubber filling oil from slurry oil need to be reduced to 3% and 10mg/kg. Meanwhile, the C_A must be maintained above 10% in order to sustain the compatibility with the body of rubber. This contradiction can be solved by screening or compounding extractants.

Aiming at the problem that traditional lithium bromide absorption refrigeration systems can hardly use low-grade heat sources, we introduced the air gap membrane distillation (AGMD) technology into the system and established a new process to make use of low grade heat source. According to the existing AGMD data of the FAS (1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane)/Al₂O₃ tubular composite membrane, the thermal calculations were completed for a typical lithium bromide absorption refrigeration system based on AGMD. The results show that the coefficient of performance (COP) of the refrigeration system is small, only 0.280, so the process needs to be further optimization. After thermodynamic analysis, an optimum process was determined: adding a loop at the outlet of the membrane generator to improve the original process of the refrigeration system. The results indicate that the COPincreases with the increase of the reflux ratio. When the ratio reaches 8, the COP could reach 0.765, which is 1.74 times greater than that of the system before improvement and greatly improves the performance of the refrigeration system.

Based on the urgent needs of energy resources and environmental protection, combined with the severe situation of heating problems in northern China, it is necessary to further explore the sustainable development of clean heating technology. The selection of clean heating technology and heating source should also be considered according to the comprehensive factors such as resource situation, environmental protection, energy efficiency and cost, and determined after technical and economic analysis and comparison. Therefore, taking a heating project in northern China as an example, based on the new clean energy heating methods such as electric energy heating, natural gas heating and heat pump heating, this paper introduces the principle of each distributed central heating technology, analyzes the advantages and disadvantages of each clean heating technology, and uses a specific example to analyze the technical scheme of the heating area combined with the evaluation indexes such as cost, service life and primary energy consumption The comprehensive analysis of economy and energy saving is carried out to develop low-carbon economy and promote sustainable development, so as to provide some reference for the selection of heating mode in northern China.

At present, there are few researches on the thermal storage performance of KAl(SO₄)₂·12H₂O and few thermal storage devices use KAl(SO₄)₂·12H₂O as phase change heat storage material. The preparation and thermal storage performance of KAl(SO₄)₂·12H₂O were summarized and the thermodynamic performance was analyzed. The thermodynamic performance analysis showed that the ambient temperature and initial temperature had little influence on the exergy efficiency of PCM, while the termination temperature had greater influence on the exergy efficiency. When the initial temperature is 328K and the ambient temperature is 288K, the optimal termination temperature is 370K. At the same time, KAl(SO₄)₂·12H₂O was applied to the mobile heat storage device by numerical simulation, and the change curves of liquid phase ratio and temperature with time were obtained. It shows that KAl(SO₄)₂·12H₂O is a kind of low temperature heat storage material with good performance.

Increasing the hydrate formation rate (r_H) and the conversion rate of the water into hydrate (R_WH) by using surfactants is the main method to increase the economic value of hydrate-based technologies (HBTs). Sine foams are detrimental to the industrial application of HBTs, poly(sodium 4-styrenesulfonate) (PSS), which is a surfactant with low foaming ability, has good potential in the fields of HBTs. Based on the investigation on the thermodynamics of the hydrate formation in presence of PSS in this paper, this paper proposed a thermodynamic model of ethylene-PSS solution system to quantitatively describe the thermodynamic effect of PSS on the formation of structure Ⅰ hydrate. The above model can predict the thermodynamic equilibrium hydrate formation pressure accurately: the average related deviation is 1.1% and the maximum related deviation is 3.8%. Based on the above investigations, this paper investigated the effects of the initial concentration of the PSS in liquid phase (w_p,0) and thermodynamic driving force on the r_H, the final R_WH and other parameters. The experimental results show that, PSS had little negative thermodynamic effect on the formation of structure Ⅰ hydrate. The presence of PSS not only increased the final R_WH from 59.6%±1.9% to higher than 80% but also significantly increased the r_H. When pressure/w_p,0 was lower than a specific value, both the final R_WH and the r_H can be significantly increased by increasing pressure/w_p,0. When pressure/w_p,0 was lower than the specific value, neither the final R_WH nor the r_H can be significantly increased by increasing pressure/w_p,0.

In this paper, the recent advances on the study of the Co-based catalysts for Fischer-Tropsch synthesis, i.e., the deactivation mechanism, regeneration method of catalyst and how to prolong the catalyst life,are reviewed. The main causes of catalyst deactivation in Co-based FTS are poisoning, sintering of Co, carbon deposition, re-oxidation, metal-support solid state reactions, surface reconstruction, surface blockage and attrition. Carbon deposition and sintering of Co are the main reasons of Co-based catalyst deactivation, the key to prolong the life of Co-based catalysts for FT synthesis is to improve the resistance to the sintering of Co and coke deposition. The resistance to the sintering of Co could be improved by enhancing the interaction between the active metal Co and the support, controlling the Co metal particle size distribution and adopting coated or confined method. The carbon deposition can be inhibited by adding promoters, adjusting the experimental conditions (e.g. H₂/CO, GHSV). The catalyst could be regenerated by hydrogen treatment, de-wax, oxidation and reduction, de-wax, oxidation, solution treatment and reduction, in order to reactivate catalyst efficiently, the selection of optimal regeneration method should be combined with the main reason of catalyst deactivation. In the future, it is the key to improve the stability of catalyst and solve the industrial scale-up research of catalyst regeneration technology.

The particle size of conventional SAPO-11 molecular sieve is large. When it is used as the support for a bifunctional catalyst for alkane hydroisomerization, it will reduce the utilization ratio of the pore volume and acid center of the support, and increase the residence time of alkane molecules in the pores. SAPO-11 molecular sieve with small particle size has short pore length, which makes it easier for alkane molecules to diffuse, and has more exposed pores, which improves the accessibility of catalytic active sites. Aiming at the problem that SAPO-11 molecular sieve synthesized by conventional hydrothermal method has a large particle size, which reduces the utilization ratio of pore volume and acid center, and increases the residence time of alkane molecules in the pores, so that the alkane molecules undergo cracking reactions under the further action of acid sites in the pores. The latest research progress of the preparation methods of small-particle SAPO-11 molecular sieves and their advantages and disadvantages were reviewed, and the influencing factors in the synthesis of small-particle SAPO-11 molecular sieves were introduced. The key points, urgent problems to be solved and development trends of the synthesis technology of small-particle SAPO-11 molecular sieves were analyzed, and pointed out that the future research should focus on the SAPO-11 molecular sieves with small particles and hierarchical pores, which also have a good thermal stability, and realize the greening of the synthesis process, the greening of the template agent and the greening of the solvent.

Based on the conversion efficiency of PEMFC is mainly limited by the slow kinetics of oxygen reduction reaction (ORR) on the cathode. The design of an efficient and stable low-platinum (Pt) catalyst will not only reduce the cost of the industrial application of PEMFC, but also can improve the performance of the catalyst. Currently, researchers have conducted a lot of research in this area, including the development of Pt nanostructures with adjustable crystal plane, high-index crystal plane and Pt-M (M is a transition metal) alloy. In this paper, the effects of different additives on the morphology of the synthesized ORR Pt-based catalysts were reviewed. The additives involved include protective agent, complexing agent, capping agent, reducing agent, dispersant, etc. Typically, the synthesis of Pt with regular tetrahedron, cube, octahedron and concave nano cube with high index plane by means of wet chemical method, electrodeposition method, alloy method and solvothermal method is presented specially.In addition, the future challenges and development direction of crystal surface control of Pt-based catalysts are summarized.

Hydrogen energy is a kind of renewable energy with great potential due to its high energy density and environmental friendliness. It can effectively alleviate and even solve the global climate challenges caused by traditional fossil energy. Solar photocatalytic hydrolysis is an ideal method for hydrogen production, and photocatalytic catalyst is the core of research in this field. This paper introduces the research status and progress of TiO₂, CdS and g-C₃N₄, the 3 typical and promising single-phase catalytic materials, and summarizes the characteristics and modification methods of each catalyst. By changing the surface morphology or dopig with other substances, it can effectively improve the solar utilization and suppress the recombination of photogenerated electron/hole pairs, and thus improve the photocatalytic activity and stability. But eventual industrialisation is still a long way off. At last, the problems faced by photocatalysts for hydrogen production were pointed out and the future research directions were prospected, which provided reference for the design of efficient and stable photocatalysts in the future.

Owing to the oxidation ability of metal free catalysts is not as good as that of metal oxides, metal free catalytic systems such as carbon based and boron based catalysts have unique advantages for oxidative dehydrogenation of propane. Through the modification of heteroatoms such as nitrogen and phosphorus, the surface environment of metal free catalysts can be adjusted to further improve their catalytic activity. In this paper, the application of low-cost environmental friendly metal-free propane dehydrogenation catalysts such as carbon based and boron based catalysts, and the technology frontier of conversion of propane to propylene are reviewed. The mechanism of propane oxidative dehydrogenation of ordered mesoporous carbon materials, nano-carbon materials (nanofibers, graphene, carbon nanodiamonds, etc.) and hexagonal boron nitride materials are described and the improvement of their catalytic activities by heteroatom modification. The future direction and the development of new materials for propane dehydrogenation are also prospected.

Photo-catalytic oxidation degradation of pollutants in printing and dyeing wastewater has wide application prospects and great practical significance. In this study, Co-P compounds with configuration limitation were designed and synthesized. They were prepared by conventional solution reaction method. Their activity was evaluated by investigating the degradation of methylene blue by the catalyst, using methylene blue to simulate the pollutants in high concentration printing and dyeing wastewater. The effects of metal ratio, catalyst dosage, catalytic time and catalytic temperature on the catalytic effect were investigated. The catalysts were characterized by XRD, FTIR and SEM. The experimental results show that Co²⁺ ion and organic phosphine ligand successfully. The precipitation in the main compounds containing Co-P compounds, also contains a small amount of organic phosphorus and other impurities. There are many porous structure in the Co-P crystals, which makes it with good absorption and photo-degradation of methylene blue. According to the experimental results, the optimum ratio of the catalyst raw material for synthesis is as follow: 1.4-(two phenyl phosphine) butane to cobalt chloride six hydrates is 2 to 1. The best catalytic conditions are: the best dosage of catalyst is 50mg, the illumination time is 3 hours, the best catalytic temperature is 50℃, under which the degradation ratio can reach to 15.45%. That is 4.6mg per liter. Calculated based on the dye concentration about 5mg/L in grade Ⅲ wastewater, the degradation rate is over 92%. It is expected to be widely used in the degradation of pollutants in printing and dyeing wastewater.

Using Bi(NO₃)₃·5H₂O and Co(CH₃COO)₂·4H₂O as raw materials, heterostructure composite semiconductor photocatalyst Co₃O₄-Bi₂O₂CO₃ was prepared by chemical precipitation-hydrothermal method. The physical and chemical properties of the catalyst was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse-reflectance spectrum (DRS) and photoluminescence (PL) spectra. The results showed that the introduction of Co₃O₄ does not change the phase structure of Bi₂O₂CO₃, but promoted the visible light absorption capacity of Bi₂O₂CO₃, increased the number of oxygen adsorbed species on the surface of Bi₂O₂CO₃, and inhibited the recombination of photogenerated carriers. The photocatalytic decolorization experiment of Rhodamine B (RhB) by the composite photocatalyst shows that the introduction of Co₃O₄ can significantly improve the photocatalytic decolorization ability of Bi₂O₂CO₃ catalyst. In particular, the Co₃O₄-Bi₂O₂CO₃ sample with the doping amount of 0.6% has the best photocatalytic performance. The RhB dye removal rate can reach 97% under the irradiation of visible light at room temperature for 30min. This study provides a simple and feasible technical route for the preparation of composite photocatalysts. The novel Co₃O₄-Bi₂O₂CO₃ hetero-structured photocatalysts may have potential applications in environmental purifications.

The adsorption and reduction process of NO_x in a fixed bed reactor was studied by combining experiment and simulation. Commercial cordierite and TiO₂ were selected as the main forming catalyst matrix materials, and copper, iron, cerium compound metal oxide was used as the active component to prepare the honeycomb forming catalyst. The adsorption performance and reduction activity of the honeycomb catalyst were measured. The reaction kinetics model of NO_x removal by CO in fixed bed reactor was established. Due to the decoupling decomposition of CO reduction, the reaction model of removal was also composed of adsorption model and reduction model. The adsorption model is established by the differential mass balance equation of solid and gas phases, and the reduction model is composed of a set of differential equations. The key parameters of the model were fitted by the NO_x adsorption curves of fixed bed and the conversion rates of NO_x at different temperatures. The reaction kinetics model of CO removal of NO_xon the forming catalyst was obtained. The model was in good agreement with the experimental data. On this basis, the penetration curve of adsorption process and the conversion rate of reduction reaction under other conditions were simulated. This model can better reveal the reaction kinetics of NO_x reduction by CO on honeycomb catalyst, and provide theoretical guidance for experiments or engineering.

Silicon is considered as a strong competitor for the next generation anode materials due to its high theoretical capacity, low lithium insertion potential, wide sources and environmental friendliness. However, the huge volume expansion in the process of lithium ion deblocking leads to the pulverization and fracture of the active material, which leads to a series of problems such as poor cycle performance, fast capacity degradation and even electrode failure. So far, there are a lot of reports about modified silicon materials. This paper will focus on the nanostructured design of silicon-based materials and the combination of silicon/carbon materials. Firstly, the lithium storage and failure mechanism of silicon are analyzed, and the influence of silicon failure on its electrochemical performance is understood from the mechanism. Secondly, we theoretically explained the mechanism of nano-scale silicon materials to alleviate the volume effect, and demonstrated the advantages of nano-silicon materials from the aspects of structure design, material synthesis, morphological characteristics and electrochemical performance. Subsequently, the research progress of silicon-carbon composites was summarized in terms of relieving volume expansion, improving electrical conductivity and forming a stable solid electrolyte (SEI) film. In addition, the mechanism of electrochemical performance enhancement by introducing conductive polymers and metals into silicon-based materials is also discussed. Finally, several suggestions are put forward for the industrial application of silicon-based materials in terms of improving the first Coulomb efficiency, SEI film stability and mass loading capacity.

In recent years, with the development of the electronics industry, people have begun to pay more attention to the application of nanomaterials in electronic printed circuit boards (printed circuit board, referred to as PCB). New, efficient, economical, and environmentally friendly technical methods have gradually replaced traditional manufacturing processes. This article reviews the preparation methods of different kinds of nano-material conductive inks and the development of new printed circuit board preparation technologies. By comparing the effects of different reactants, additives and different methods on the properties of the final nano-copper conductive inks, the adaptation is introduced. Preparation technology of nano materials for different requirements. In addition, the influence of different sintering processes and printing processes on the final PCB circuit generation is introduced. Compared with the disadvantages of traditional copper-clad laminate etching circuit technology, such as high pollution, material waste, and complex process, the new process combines the properties of nano materials, uses high-precision equipment, and focuses on the direction of low cost, less pollution, short time, and low energy consumption. A series of studies, and discussed the future development direction of the PCB industry in 5G applications and possible opportunities and challenges.

As a green energy technology, fuel cell technology has great potential in reducing energy consumption and environmental pollution. Membrane electrode assembly (MEA) is the core component of proton exchange membrane fuel cell (PEMFC). The smooth work of electrochemical reaction in MEA requires the coordination of all the functional parts. The performance of the fuel cell is restricted by the function parts of MEA, such as mass transfer, conductivity, proton conduction, catalysis, etc. According to the preparation method, MEA can be divided into catalyst coated substrate (CCS)-type MEA, catalyst coated membrane (CCM)-type MEA, ordered MEA and integrated MEA. The performance of MEA is not only determined by the catalyst loading, but also influenced by its structure design and preparation process. In this paper, the common improvement methods in the preparation of MEA are introduced. The research progress of catalyst spraying, blading, slot die coating, Nafion content in catalyst slurry composition and solvent polarity selection, catalytic layer gradient, patterning of catalyst layer and improvement of interface structure, PEM structure enhancement, patterning and film-forming method are discussed. It should be noted that the design of catalytic layer/proton exchange membrane (PEM) interface and catalytic layer/gas diffusion layer (GDL) interface will also directly affect the performance of MEA.

Due to the unique honeycomb structure with a large number of oxygen-containing groups, graphene oxide (GO) has been widely used as ideal construction blocks for water treatment separation membrane. GO membrane has good physical properties, excellent chemical stability and unique two-dimensional layered structure, which has attracted increasing attention in the fields of wastewater treatment, desalination, and ion sieving. In the water treatment processes, GO membrane shows good retention effect on organic matter and ions, however, meanwhile, the membrane itself suffers from some problems such as low water flux and poor stability. This paper reviews the current research progress of GO membrane in water treatment, including the preparation method and water treatment application of GO membrane, optimized method of separation performance and mass transfer mechanism on GO membrane. Finally, the development directions of GO membrane in structure regulation and performance improvement is summarized and prospected. It provides some references for designing and preparing GO membrane with high performance in water treatment.

The technology of phase change heat storage is one of the effective means to solve the heat imbalance in time and space. The development of high-performance composite phase change material (PCM) has become the focus of current researchers. At present, the low thermal conductivity and poor cyclic stability of stearyl alcohol(SAL) and other organic PCM limit their practical application. Herein, SAL was used as PCM and expanded graphite(EG) as porous matrix of high thermal conductivity. Sixteen kinds of SAL/EG composite PCMs (EG content was 7%, 14%, 21%, 28%(mass), sample density was 700kg/m³, 800kg/m³, 900kg/m³, 1000kg/m³) were prepared by adsorption form-stable process. The microstructure, thermal storage capacity, thermal conductivity, cycle stability and heat storage/release properties of the composite PCMs were studied and analyzed. The results show that SAL is completely filled in the porous network of EG. The horizontal thermal conductivity of the sample with sample density of 900kg/m³ and EG content of 28%(mass) is the highest, with a value as high as 28.58W/(m ? K), which is 74 times higher than pure SAL[0.38W/(m ? K)], which is about 4.8 times of the corresponding vertical thermal conductivity[5.99W/(m?K)]. In addition, the heat storage/release performance at the center of the sample was studied on the heat storage experiment system. The results show that the sample density is 900kg/m³ and the sample with the EG content of 28%(mass) has the maximum heat storage/release rate. The time of latent heat storage and release stages is 53minutes and 20minutes. At the same time, the thermal conductivity and melting-solidification characteristics of the samples are verified, which shows that SAL/EG composite PCMs has stable and reliable heat storage/release performance.

At present, petrochemical resources are subject to challenges such as limited reserves and environmentally unfriendly utilization process. Biomass fuel ethanol can begin to emerge as an alternative energy source. Pervaporation is a way to separate ethanol, which is energy-saving and environmentally friendly. The development of natural highly selective pervaporation membranes has become one of the research hotspots This project proposes to utilize the hydrophilicity and membrane-forming properties of calcium lignosulfonate (CaLS), it was blended with natural polysaccharide sodium alginate (SA) to prepare CaLS/SA blend membranes with different CaLS content. The blend membrane was characterized and analyzed by Fourier transform infrared, X-ray diffraction, contact angle and scanning electron microscope methods. Analysis shows that CaLS and SA are fully and uniformly mixed, and the introduction of CaLS can improve the hydrophilicity of the SA membrane. The effects of CaLS content and operating temperature on the separation performance of ethanol solution with 10% water content were further investigated. The results show that when mass ratio of CaLS/SA is 5%, the separation factor of CaLS/SA blend membrane reaches 2872 and the permeation flux reaches 796g/(m² · h), which is 160% and 70% higher than pure SA membrane respectively, confirming the calcium lignosulfonate application potential in the field of membrane separation.

The chemical composition of electrolytic manganese slag is required to have good consistency in the composition of cement, but the high sulfur content limits its mixing in cement production. In this study, coke was used as the reducing agent, and the electrolytic manganese slag was thermally decomposed to generate SO₂ under different conditions in a nitrogen atmosphere. The solid product was analyzed by SEM and XRD. The gas analyzer analyzed the release of SO₂. The high temperature reduction roasting method was used to remove the sulfur in the electrolytic manganese slag. The effect of roasting temperature and coke addition on the phase and sulfur content of the roasted product was explored. Experimental results show that the optimal conditions for generating SO₂ are 4% coke addition and a decomposition temperature of 1000℃. Under the best conditions, the maximum concentration of SO₂ is 3513mg/m³, which can be used to produce sulfuric acid. When the temperature of the calcined solid product is 900℃ and the coke addition is 4%, the SO₃ content can be reduced to 2.17%. According to the provisions of GB175—2007 "General portland cement", the SO₃ content in cement must be less than 3.5%, and the electrolytic manganese slag roasted product can be used as a cement raw material. It proves the feasibility of electrolytic manganese slag as a cement additive, and provides a theoretical basis and technical reference for the comprehensive utilization of electrolytic manganese slag

The massive emission of CO₂ during the combustion of fossil fuels has attracted researchers' attention about the biological methanation of CO₂. In the process of anaerobic organic matter biodegradation, the flora associated with the biological methanation of CO₂ are mainly anaerobic hydrogenotrophic methanogens. Researchers have focused on the effect of temperature on the process of anaerobic hydrogenotrophic methanogenesis, which is important to promote the development of anaerobic hydrogenotrophic methanogenesis. In this paper, we introduced the important roles of hydrogenotrophic methanogens in anaerobic biodegradation processes, and summarized 32 obligate hydrogenotrophic methanogens that utilize only H₂ and CO₂ for CH₄ production. We also showed that hydrogen can be derived from the decomposition of fossil fuels, biomass, water, and industrial gases. Then, the efficacy of anaerobic hydrogenotrophic methanogenesis at different temperature ranges were reviewed, and the effects of different temperature change ways on anaerobic hydrogenotrophic methanogenesis were presented. Finally, an outlook was put forward from the aspects of hydrogen sources and temperature change.

The monoclonal antibodies against three calcium channel membrane proteins were successfully prepared by using voltage-gated calcium channel membrane protein (Cch1p), stretch-activated calcium channel membrane protein (Mid1p), and transient receptor potential calcium channel membrane protein (Yvc1p) in Saccharomyces cerevisiae as the study materials. The epitopes of three membrane proteins were analyzed by bioinformatics methods. Based on the analysis results, the genes of three epitopes were cloned, and recombinant proteins were expressed and identified. The BALB/c mice were immunized with three recombinant antigens which were purified by Ni²⁺-NTA resin affinity chromatography, respectively. The monoclonal antibodies were generated by the cell fusion method and their titers were detected by ELISA. The reactivity and specificity of three monoclonal antibodies were tested by Western blot with three purified recombinant antigens and natural Cch1p, Mid1p and Yvc1p. The results showed that three antigen epitopes region may be located in 1—300 amino-acid residues, 359—548 amino-acid residues, and 1—236 amino-acid residues. The purpose band sizes by gene cloning were 926bp, 570bp and 708bp, which were consistent with the expected results. Furthermore, the molecular weight of three antigen proteins from prokaryotic expression systems were 60000, 25000, 30000, respectively and three bands were proved to be correct by Western blot. The ELISA results showed that three monoclonal antibodies prepared by cell fusion method presented high titers of 1∶256000, 1∶128000, and 1∶64000. These antibodies could detect the purified recombinant antigens and natural proteins of Cch1, Mid1 and Yvc1 in Western blot. These results indicated that the prepared monoclonal antibodies against Cch1p, Mid1p and Yvc1p could be successfully used for the related research about the detection of the expression of calcium channel membrane proteins in S. cerevisiae.

DNA molecule has the special ability of self recognition. DNA origami is a new technology for the precise design and assembly of nucleic acid nanomaterials. Researchers can use stapling chains complementary to DNA scaffold chains to fold long-chain nucleic acids into nanostructures consistent with the preset model. DNA origami was first proposed by Rothemund in 2006. Since then, people have used m13mp18 single strand linear DNA to self assemble various nano patterns. In order to find more nucleic acid materials for DNA origami research, this study takes the citZ gene sequence of Bacillus subtilis 168 as the research object, adopts the improved Daedalus software, introduces the "key" structure design, uses the "bottom-up" method to make the DNA molecules self-assembly, and designs the citZ gene nano box with a three-dimensional volume of 50.71nm×50.71nm×50.71nm, It is only possible to open the lid and release the contents of the box when a recognized gene and a matching "key" are encountered. The nucleic acid nanomaterials can also adjust the length of DNA sequence and the internal space of the box, which is expected to become a new targeted drug delivery carrier. At the same time, DNA Designer 1.0 was developed.

The surfactant is one of the key factors that affecting the characteristics of microemulsions. Polysorbate 80 (Tween 80), alkyl polyglycoside 1214 (APG 1214), sodium dodecyl benzene sulfonate (SDBS), sodium lauryl polyoxyethylene ether sulfate (AES), sodium dodecyl sulfate (SDS) and rhamnolipid of 95% purity (R-95%) were selected for emulsification property and critical micelle concentration analysis. The capacities and cost of oil solubilization of microemulsions were proposed by analyzing the pseudo-ternary phase diagrams, particle size distribution and interfacial tension. The results showed that APG 1214, SDBS and Tween 80 were easier to form microemulsions because of their better emulsification properties and lower critical micelle concentrations. A single-phase microemulsion can spontaneously formed by five surfactants (Tween 80, SDBS, APG 1214, SDS, AES), n-butyl alcohol, water and 3# white oil. The area of single-phase microemulsion were showed as AES type>SDS type>APG 1214 type>Tween 80 type>SDBS type. The maximum capacities of oil solubilization were showed as SDS type>AES type>APG 1214 type>Tween 80 type>SDBS type. The minimum cost of oil solubilization were showed as AES type<SDS microemulsion<SDBS type<APG 1214 type<Tween 80 type. The ratio ranges of surfactant + co-surfactant to water in SDS and AES microemulsions which have better capacities and lower cost of oil solubilization were (6∶4)—(7∶3) and (7∶3)—(8∶2) respectively which were appropriate for oil cleaning applications.

Aiming at the quality problem that the water resistance of alkyl ketene dimer (AKD) surface sizing recycled paper is not significantly improved in the actual paper making project of a paper mill, the paper samples of AKD sizing produced by paper mill were characterized by contact angle, infrared spectra (FTIR), thermogravimetry (TG), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy spectrum (EDS) research methods. The results show that the change in paper-like contact angle shows two-sided difference, the initial contact angle of the positive surface of the sizing paper is 114.5°, and the reverse surface is 118.5°, the positive urban wetting contact angle (≥90°) is less than 9 minutes, and the negative direction is 9 minutes. The paper sample does not have long-lasting water resistance, and the contribution of the AKD sizing system on the long-acting water resistance of paper is not obvious. After the application, the AKD feature functional group β-vinyl propyl lactone disappears, the weight loss behavior of the sizing paper sample and the sizing extraction paper sample were different in different atmosphere, the atomic composition and the atomic valence chemical environment are different. The sizing paper sample contained soluble substance that could be extracted by tetrahydrofuran (THF) (AKD hydrolysate ketone), and the relative content of the hydrolysate ketone was higher than 99%. The main reason for the adverse sizing of AKD is the improper compatibility of sizing system, which leads to the shortage of long-term water-resistant products in the esterification grafting reaction of AKD and cellulose.

nitrate pollution in water Environment is a common problem. solid phase denitrification (SPD) technology has attracted increasing attention because of its significant advantages over water-based denitrification in water remediation. this paper presents new views on the application of SPD in water remediation, introducing the process and mechanism of nitrogen conversion in SPD, such as direct denitrification, dissimilatory nitrate reduction to ammonium and anaerobic ammonia oxidation; discussing the main processes of carbon substrate conversion in SPD; studying the main limitations of SPD, including low carbon source availability, NO₂^- and N₂O accumulation, dissolved organic carbon release and NH₄ production, and summarizing the relevant limiting factors; moreover, some new measures are introduced to mitigate these limitations, such as the application of biodegradable polymer substrates and heterotrophic autotrophic denitrification (HAD) processes; finally, methods for simultaneous removal of nitrate and some typical pollutants to expand SPD applications are discussed. this review attempts to improve our understanding of denitrification processes in wastewater treatment or water remediation works.

MSWI (municipal solid waste incineration) is an important way to deal with MSW (municipal solid waste) in China, which can realize the reduction, harmlessness and resource utilization of MSW. Due to the high water content, high salt content and low calorific value of MSW, MSWIs generally face serious ash deposition which not only brings hidden dangers to the safe operation of waste incinerators, but also seriously affects the economic benefits of waste incineration power plants. This article reviews the current research status of ash deposition on the heat exchange surface, introduces the mechanism of ash deposition, and analyzes the impact of fly ash particle size, flue gas flow rate, flue gas temperature, and heat exchange surface temperature on the MSWI. Based on the existing ash deposition model of coal-fired boilers and biomass furnaces, it is necessary to develop a model that can predict the ash deposition and slagging problems of MSWI. Aiming at the serious problem of ash deposition, a series of methods for equipment improvement, process optimization, and the use of additives and coating technologies to inhibit the growth of ash deposits are proposed. Finally, the current key research contents are summarized, and future research directions are proposed, such as establishing a model that can accurately predict the growth of ash deposition in waste incinerators, and developing new coatings that can effectively reduce ash deposition on the heat exchange surface,which provides reference suggestions for the operation of waste incineration power plants.

Coking wastewater is a kind of typical toxic wastewater which is difficult to be degraded, and it is recognized as a kind of refractory industrial wastewater in the world. In particular, the cyanide in coking wastewater has the characteristics of high content and high toxicity. If discharged randomly, it will pollute the water source and farmland, resulting in the death of fish and the reduction of crop production. Therefore, how to remove cyanide from coking wastewater efficiently and cheaply has become a problem worthy of consideration and research. This paper summarizes various treatment methods of cyanide from coking wastewater and their application, which are mainly divided into two categories: biological methods and physicochemical methods. Biological method is the use of microorganisms to degrade pollutants in wastewater, but the single use of biological method cannot meet the discharge standard, so biological method should be combined with other methods for joint treatment. Physical and chemical methods, such as alkaline chlorination, ferric cyanide precipitation, Fenton process, activated carbon adsorption, ozonation, ion exchange method, sulfur dioxide and air method, MBR and membrane treatment, have their own advantages and disadvantages. This paper briefly introduces and analyzes the principle and application of the current treatment methods, and the development suggestion of joint treatment is put forward. It is hoped that it can be helpful for the treatment of cyanide in coking wastewater.

A large number of perfluorinated alkyl and polyfluorinated alkyl substances (PFASs) have been found in wastewater and drinking water in nature, so perfluorinated or polyfluorinated alkyl substances have become a global problem of organic pollutants. Conventional water treatment techniques including coagulation, flocculation, filtration, precipitation and biological treatment can not be completely removed PFASs. Specific advanced treatment technologies include adsorption, membrane treatment and oxidation can be effectively removed PFASs. Therefore, it is necessary to understand the removal mechanism of various PFASs during advanced treatment, especially the difficulty of understanding the migration of compounds in aqueous solution due to the different physicochemical characteristics of various PFASs. There is little information on the effect of water quality conditions on removal of PFASs in existing studies. Therefore, in this study, we comprehensively summarize the effects of different water quality conditions (such as pH, temperature, background ions, natural organic matter and solute concentration) on removal of PFASs, as well as the latest knowledge of advanced water treatment technologies such as adsorption, membrane treatment and oxidation.

Chlorine is a trace element in coal, which is released in the form of HCl gas in the combustion process. HCl has adverse effects on limestone-gypsum wet desulfurization facilities in coal-fired power units. The technology of HCl removal from coal-fired flue gas by alkaline absorbent was put forward based on chloride ion material balance in wet desulphurization absorber slurry. The technology of HCl removal was reviewed from the aspects of the types of alkaline absorbent, the effect of reaction conditions on HCl removal, and the mechanism of HCl removal. The research direction of removing low concentration HCl from coal-fired flue gas with alkaline absorbent was pointed out.

By introducing the properties and different reaction mechanisms of ozone, the application and development of ozone in water treatment are reviewed, and the three key parts of ozone treatment equipment are introduced, including ozone generator, ozone contact reaction system and ozone destruction device. On the basis of process design, activation and catalytic method development, the optimization of mass transfer process of ozone in water is also an important part of technological innovation. Therefore, the influencing factors of mass transfer rate of ozone are elaborated, and the ozone contactor is a specific engineering means to improve mass transfer. Based on people's understanding of the mass transfer process of ozone, ozone contactors are gradually designed and improved. In this paper, the development history and research status of several typical types of contactors are introduced, and their mass transfer characteristics are compared and summarized. The results show that the volumetric mass transfer coefficient K_La of static mixer can reach 2s^-1, and the K_La of jet contactor and microbubble reactor can reach 216.15s^-1 and 4000s^-1 respectly under the condition of small flow rate. It is found that there are still some problems in the ozone reaction, such as the bubble diameter and other parameters can be paid more attention, and the interface reaction in the ozone system can be studied further.

Hazardous chemical accidents occur frequently as the chemical industry is rapidly developed in China. During the emergency disposal process of hazardous chemical accidents, the decontamination technology has been one of the most important technical part. In this paper, a preliminary decontamination spectrum of potential hazardous chemicals was established as considering the toxicity of chemicals, production and sales, the necessity of decontamination and other factors. Meanwhile, on the basis of discussing the decontamination principle and decontamination agent, the catalytic activation mechanism and the application of hydrogen peroxide combined with the inorganic catalysts and organic activators had been mainly elaborated. The inorganic catalytic system mainly includes metal ions, metal salts and metal ligands. The active ingredient of the compound is ·OH, ¹O₂ and so on. Organic activators mainly include esters, amides, amidines, guanidine and nitriles. The active components are peroxyacid or peroxyimino acid. All kinds of systems have been studied and applied in the fields of disinfection and disposal of hazardous chemicals, bleaching and dyeing, and are expected to become the main body of the development of disinfectants for hazardous chemicals in the future. This paper can provide a theoretical basis for the research and development of peroxide disinfectants, and lay a technical foundation for emergency rescue and decontamination of hazardous chemical accidents.

There are volatile heavy metals, ammonia nitrogen, VOCs, chlorine and other volatile components in desulfurization wastewater. In the application of hot flue gas evaporation, volatile components will be re-released in the gaseous form, leading to the potential risk of cyclic enrichment in desulfurization wastewater. Based on the analysis of the sources and forms of volatile components in desulfurization wastewater, the migration and transformation of volatile components in hot flue gas evaporation are discussed. The migration and transformation of volatile pollutants is a heterogeneous physicochemical process. The volatile components in the solid or liquid phase of waste water can be separated into flue gas in gaseous or granular form through pure physical action or reaction with other components. Then further pyrolysis conversion, adsorption and condensation with flue gas components will occur. Current researches have shown that only a small amount of chlorine can be precipitated in the form of HCl, while heavy metals are commonly thought to be precipitated in the form of particles. However, organic matters and ammonia nitrogen are not paid attention to. So far, it has only been limited to the investigation of macroscopic phenomena, and the relevant quantitative research is scarce. Under the background that the hot flue gas evaporation technology without or only with simple pretreatment has gradually become the mainstream route of zero discharge of desulfurization wastewater from power plants, the study on the migration and transformation of volatile components in the process of desulfurization wastewater evaporation is particularly important.

The composite flocculant was prepared by compounding polysilicate aluminum iron, polyacrylamide, nano zero valent iron and activated carbon. On the basis of single factor experiment, the influences of m(PSAF)/m(PAM), compound temperature and compound curing time on the preparation of composite flocculant were investigated with turbidity and COD of treated effluent as evaluation indexes. Box Behnken response surface methodology was used to establish a mathematical model with COD content as the response value to optimize the preparation parameters. The results showed that the mathematical model was significant and the fitting degree was good, which could be used to analyze and predict the performance of the composite flocculant. The optimal process parameters were m(PSAF)/m(PAM)=14.63, compound temperature=70℃ and compound curing time =3.02h. The COD content was 756.54mg/L The deviation between the experimental value and the predicted value was 2.14%. Field experiments show that the composite flocculant can reduce turbidity, COD, oil content and ammonia nitrogen content by 96.74%, 94.35%, 75.77% and 74.27% respectively, meeting the requirements of entering the biochemical treatment system.

Volatile organic compounds (VOCs) are important precursors of photochemical smog, which have a great impact on the formation of tropospheric ozone and secondary fine particle pollutants, and are the focus of current atmospheric environmental pollution research. At present, activated carbon adsorption method is widely used in the treatment of VOCs because of its mature technology, simple operation and high adsorption efficiency. In this paper, a series of activated carbons were prepared from wild hickory as raw materials, flue gas and ferric nitrate as activators, and their adsorption and regeneration properties were studied by fixed bed adsorption device. Carbon dioxide and water vapor were used to simulate flue gas and activated in a fixed flow flue gas activation atmosphere. The effects of carbon dioxide and water vapor in flue gas and different amounts of ferric nitrate on pore structure and adsorption regeneration performance of activated carbon were discussed. The detailed characteristics of activated carbon were studied by N₂ adsorption desorption experiment, SEM, Raman and FTIR. The results show that when the mass fraction of ferric nitrate is 0.2%, the AC-3 has the largest specific surface area and average pore volume, which are 923m²/g and 2.57nm, respectively. Its saturated adsorption capacity for VOCs ethyl acetate was 973.04mg/g. In this experiment, AC-3 activated carbon was activated and regenerated by flue gas. After three repeated adsorption desorption regeneration experiments, the saturated adsorption capacity of AC-3 activated carbon was still above 91.5%. The waste flue gas resource utilization and activated carbon recycling were realized, so as to achieve the goal of waste gas pollution adsorption treatment.

Using CPVC (chlorinated polyvinyl chloride) ultrafiltration membrane as the base membrane, after co-deposition of TA (tannic acid) and PIP (piperazine) on the surface of the CPVC membrane, interfacial polymerization is carried out with the crosslinking agent TMC (trimesoyl chloride) to obtain a PA/TA/CPVC composite nanofiltration membrane, the PA/TA/CPVC composite nanofiltration membrane was characterized by SEM, AFM, FTIR and contact angle, the effects of drying time, TA/PIP concentration ratio, TA+PIP total concentration, and TMC concentration on the microstructure and performance of PA/TA/CPVC composite nanofiltration membranes were discussed. The research results show that the best TA/PIP concentration ratio is 7/3, the best drying time of the TA/PIP layer is 20min, and the pure water flux of the PA/TA/CPVC composite nanofiltration membrane increases with the increase of TA+PIP total concentration and the concentration of TMC The rejection rate of PEG1000 is above 90%. The maximum pure water flux of PA/TA/CPVC composite nanofiltration membrane is 4.5 L/(m² · h · bar), and the rejection rate of PEG1000 reaches 95.8%. The maximum flux to the simulated RB5 dye wastewater is 4.3 L/(m² · h · bar), and the rejection rate of RB5 at this time is 95.4%, which shows good stability to the simulated RB5 dye wastewater.