In this paper, the harmless treatment technology of chemical distillation stills and hazardous wastes, and the specific resource utilization schemes and approaches of chemical distillation stills with different types and properties were reviewed. From the point of engineering application, the application range, advantages and disadvantages, technical status and development direction of different harmless treatment technologies for distillation reactor residues were described and analyzed. According to the composition and physical properties of different rectification still residues, the resource utilization scheme of different kinds of rectification still residues was summarized. On this basis, in view of the phenol-based distillation residue with large output and complex components, a diversified resource conversion and harmless treatment plan for the light and heavy components of the distillation residue was proposed, and a comprehensive analysis and development thinking were carried out on the utilization technology of residual resources in distillation residues.

The electroplating, dyeing and tanning industries produce a large amount of solid waste in the production process, as the solid waste contains the heavy metal chromium and is easily transformed into the highly toxic hexavalent chromium, resulting in the development of the entire industry being constrained. This paper provides a brief description of the causes and composition of chromium-containing sludge in various industries and introduces the conventional methods of treating chromium-containing sludge, which are no longer in line with the concept of sustainable development due to their impact on the environment. The composition of chromium-containing sludge is complex and has potential utilization value. In both conventional and resource-based treatment methods, the focus is on how to avoid the conversion of the heavy metal chromium in chromium-containing sludge into the highly toxic hexavalent chromium. An industry inquiry into the mechanism of conversion of trivalent chromium to hexavalent chromium is presented and suitable treatment methods are found to immobilise and encapsulate the heavy metal chromium. It not only inhibits the conversion of trivalent chromium to hexavalent chromium, but also allows for the resourceful use of solid waste at the same time.

As a typical kind of heavy metal ions, Cr(Ⅵ) seriously threatens the eco-system and human health due to its high toxicity, non-degradability, high mobility and bio-accumulation characteristics. As a derivative of cellulose, cellulose nanomaterials (CNM) is the most abundant natural material on earth, which is eco-friendly, highly biocompatible and rich raw material sources. Thus, the use of CNMs as heavy metal ion adsorbents for water treatment is of great significance to promote the sustainability of the society. However, pristine CNM exhibits poor affinity towards Cr(‍Ⅵ), so it is desirable to perform chemical modification and macroscopic geometry structure design for CNM to improve its removal efficiency towards Cr species. This review systematically introduces and summarizes the recent advances on the functionalization and macroscopic structure design strategies of CNM, covers the problems existing in the current field and provides an insight for the future development of CNM-based adsorbents on Cr(Ⅵ) removal application. The review is valuable for the structural design of high-performance adsorbents.

Waste activated sludge with high moisture content challenges the harmless treatment and resource utilization of sludge. In this study, low temperature hydrothermal coupling Fe²⁺-activated persulfate was used to improve the dewatering performance of waste activated sludge. The results showed that when 0.75mmol/g DS Fe²⁺ and 0.6mmol/g DS S₂O₈^2- were added at 80℃, the molar ratio of Fe²⁺/S₂O₈^2- was 1.25, capillary suction time (CST) of sludge decreased from 397.4s±7.9s to 18.9s±0.4s. It was found that in the process of activating persulfate with hydrothermal coupling Fe²⁺ at low temperature to enhance the dewatering performance of sludge, the particle size of sludge first decreased and then increased, the extracellular polymer substance (EPS) was degraded, and the floc structure was damaged. The combination of heat and Fe²⁺ accelerated the decomposition of persulfates to generate sulfate radicals (SO₄^•-) and hydroxyl radicals (^•OH) for oxidizing EPS, promoted the conversion of bound water into free water, and facilitated the solid-liquid separation of sludge. These studies provided a theoretical basis for dewatering sludge with low temperature hydrothermal coupling Fe²⁺-activated persulfate.

This paper used a thermogravimetric analyzer to study the changes in the pyrolysis properties of oily sludge (OS) before and after hydrothermal treatment. At the same time, the apparent activation energies of the samples were calculated by two model-free methods, Kissinger-Akahira-Sunose (KAS) and Ozawa-Flynn-Wall (FWO). The apparent activation energy of oily sludge treated at different hydrothermal temperatures in different pyrolysis stages was determined. The effects of hydrothermal treatment and hydrothermal temperature on the pyrolysis characteristics and kinetic parameters of oily sludge were investigated. The thermal analysis results showed that the temperature range in different pyrolysis stage intervals shifted to a lower level and the weight loss rate increased significantly in the first stage and the third stage due to the change in oil type and content after hydrothermal treatment. At the same conversion rate, the apparent activation energy of OS after hydrothermal treatment at different pyrolysis stages was lower than that of OS. According to the FWO method, as the hydrothermal reaction temperature increased from 160℃ to 240℃, the apparent activation energy of OS in the first-stage and the third-stage pyrolysis increased from 75.20kJ/mol and 171.12kJ/mol to 78.28kJ/mol and 192.59kJ/mol, respectively, and the average apparent activation energy in the second stage of pyrolysis decreased from 151.04kJ/mol to 144.18kJ/mol.

Oily sludge widely exists in the petroleum exploration, petrochemical processing and application. Because of its high viscosity, complex and stable emulsification characteristics, the treatment of oily sludge is fairly difficult with low treatment efficiency. Aiming at the problem of low separation efficiency of traditional process, this study put forward the resourceful treatment of oily sludge through multiphase compound conditioning and demulsification separation process, based on the engineering application. Firstly, the different viscosity reduction methods of oily sludge was studied. It was found that the viscosity of oily sludge could be effectively reduced by multiphase composite method, owning to the control of the emulsification state, the dissolution of the heavy components and the destruction of its spatial structure. On this basis, the resourceful treatment of oily sludge was carried out by the combination of multiphase compound conditioning and demulsification, and the influence of conditioning and demulsification process on the treatment effect was studied respectively. The results showed that the addition of water could assist the conditioning process to reduce the viscosity effectively, help disperse oily sludge aggregates and promote the dissolution and mass transfer of heavy oil. The oil was dissolved and liberated from the solid surface by the solvent. Through the control of the emulsification state and the use of high-efficiency demulsifier, the efficient separation of oil, water and solid could be realized. When the solvent dosage was 130% and the water dosage was 30%, the system was in water-in-oil state. After adding 400mg/kg water-in-oil demulsifier TJU-3, the heavy oil recovery could reach to 92.9%, and the oil phase was clean. This study could provide reference for the large-scale resource recovery and treatment of oily sludge.

Norfloxacin as one of quinolone antibiotics is widely used in medical treatment, animal husbandry, agriculture, aquaculture and other industries. In recent years, the accumulation of quinolones in the environment poses a direct or potential threat to ecosystem stability, diversity and human health. Therefore, how to rapidly degrade quinolones has become an urgent problem. However, the removal efficiency of the antibiotics is limited. Therefore, in this paper, the Au-TiO₂ photocatalyst was prepared, and the effects on the visible light degradation of norfloxacin were mainly studied by changing the reaction conditions such as pH, chloride concentration and Au-TiO₂ amount, and the highest norfloxacin degradation rate of 80% of was obtained. This study not only proved that the visible light degradation of norfloxacin by Au-TiO₂ was feasible, but also further indicated that the visible light catalytic technology was a potential method for the treatment of antibiotic wastewater.

Aiming at the problems of complex plastic components, unstable components and difficult quality control of pyrolysis oil production, this study used municipal sludge as raw material to prepare Fe-loaded sludge-based biochar catalyst, and conducted research on the experimental route of promoting tar cracking and syngas production by catalytic pyrolysis of polypropylene plastic (PP). The tar removal effect in PP pyrolysis products, the key components of H₂-rich syngas, and the effect of catalytic pyrolysis process on the surface characteristics of sludge-based biochar were analyzed. The results showed that the sludge-based biochar with FeCl₃ impregnation ratio of 5% (mass fraction, calculated as Fe) could significantly promote the catalytic pyrolysis of PP to produce hydrogen. The hydrogen yield reached 17.39mmol/g_plastic, which was higher than the biochar without Fe-loaded catalysis control group of 268.43% and the pure PP pyrolysis control group of 2046.91%, respectively. The catalytic pyrolysis process strengthened the tar cracking, and the tar cracking rate reached 29.65%. The relative proportion of alcohols in the tar component decreased, and the relative proportion of olefins and halogenated esters increased. At the same time, a special thin-layered pore structure appeared on the surface of the sludge-based biochar after catalytic pyrolysis, and the specific surface area increased to 225.90m²/g. XPS analysis found that the relative proportion of carbon-oxygen functional groups on the surface of sludge-based biochar bound to carbon, lattice oxygen and carboxyl oxygen increased, which proved that more active sites appeared at this Fe impregnation ratio.

In order to explore the method of application field of of tannery sludge protein, the biomass flame retardant coating was constructed by layer-by-layer self-assembly on the surface of cotton fabric using tannery sludge protein phytic acid and chitosan as raw materials. When the coating number reached 15TL (three layers), it could be observed by SEM that the coating was evenly adsorbed on the surface of cotton fabric. The thermal decomposition temperature (T_5%) of 15TL cotton fabric decreased, which was beneficial to the production of protective carbon layer and improved the thermal stability. Importantly, unfinished cotton fabrics burned quickly when exposed to flame, whereas 15TL cotton fabrics could not be ignited by flame and self-extinguish immediately after the fire left. Compared with unfinished cotton fabric, peak heat release rate (PHRR) and total heat release amount (THR) of 15TL cotton fabric decreased by 33.1% and 38.9%, respectively, showing excellent flame retardant performance and improving the fire safety. The gaseous and condensed analysis demonstrated that biomass flame retardant coating released non-flammable NH₃ gas, inhibited the effusion pyrolysis products as flammable gas CO, C-H compounds, ethers and carbonyl compounds, and promoted the generation of high graphitized protective carbon layer on surface of cotton fabrics.

Restricted by the construction environment of the boiler, the back water of heat network is the most easily obtained cold source for waste heat recovery. However, the high back water temperature limits the recovery of the latent heat. In order to achieve high-efficiency total heat recovery, a flue gas condensation waste heat recovery system coupled with a direct contact heat exchanger and a compression heat pump was proposed, which aimed to create an artificial cold source through the heat pump's ability to extract low-grade heat energy to meet the requirement of temperature for latent heat recovery. The waste heat recovery capacity and heating capacity of the system were experimentally studied under the condition of variable inlet water flow and temperature of the heat network back water at the inlet of the heat pump condenser. The results showed that, based on the minimum calorific value of the input gas, the heating efficiency of the system under all working conditions exceeded 100%, and the system had excellent heating capacity. Under the condition of back water temperature of 50℃ and flow rate of 40L/min at the inlet of the heat pump condenser, the exhaust gas temperature of the system could be reduced to 26.9℃, and the waste heat recovery efficiency could reach 13.85%. At this time, the condensation amount of water vapor in the flue gas was 6.5—7kg/h. It could save about 1966.42m³ of gas every year, and the investment payback period was about 3.33 years, which proved that the system had excellent energy saving and economic benefits.

In this paper, a mixing performance prediction method based on PLIF test technology and convolutional neural network technology was proposed to analyze the mixing characteristics of the flow field in the impingement flow reactor, which could accurately predict the mixing uniformity and mixing time of the concentration field in the impingement flow reactor. Mixed performance prediction model was constructed based on CNN, using the impinging stream reactor concentration field experimental data for the construction of the model of supervised training and forecasting. The prediction results showed that the mixing uniformity of prediction accuracy was 95%, and the calculation efficiency increased by 99.99%. In order to better understand the prediction mechanism of the mixing performance prediction model on the mixing uniformity, the output of the convolution layer was visualized, and the physical interpretation of the concentration field feature extraction of impingent flow reactor was given by analyzing the response of the convolution kernel through power spectrum analysis. Finally, the prediction model was used to build a fast acquisition system of mixing uniformity and apply it to study the mixing characteristics of impingement flow. The proposed prediction model based on CNN could effectively analyze the mixing characteristics of impingement flow reactor, and the prediction model was reliable and applicable to a wide range of applications, providing scheme experience for the application of deep learning algorithm in the field of impingement flow.

Methanol-to-olefin (MTO) opens up a new way to produce light olefins. Due to the limitation of the separation accuracy of the cyclone separator in the MTO reactor, the fine catalyst particles will enter the water system, resulting in large amounts of wastewater. The separation of fine particles in MTO quench wastewater is the key to realize wastewater reuse. In view of the shortcomings of the current MTO wastewater treatment technologies, a novel swirl regenerating microchannel separation technology was proposed to treat MTO wastewater, and an industrial-scale device with a treatment capacity of 50t/h was established. The device had good performance in the treatment of MTO wastewater, the average suspended solids content decreased from 143mg/L to 22mg/L, and the average suspended solids residual rate of the separation media was below 2%. The technology had a long operating cycle and high removal efficiency for suspended solids. The operating pressure was low, and the separation media were completely regenerated. The successful application of the technology had effectively alleviated the blockage of the water system of the methanol-to-olefins unit. Water resources were greatly saved and environmental pollution was reduced.

The process conditions of urea inclusion method were studied for the separation of normal and isomeric hydrocarbons in Fischer-Tropsch (F-T) synthetic light oil. The composition of raw oil was analyzed by GC-MS method. The effects of activator type, oil/urea/activator mass ratio, inclusion temperature and time on the separation performance were investigated, and the suitable conditions for the decomposition of urea inclusion compounds were obtained. The optimal inclusion conditions of F-T synthetic light oil were determined through orthogonal experiments, which were m(urea)∶m(methanol)∶m(oil)=5∶6∶1, the terminal temperature 10℃, and the reaction time 120min. Under these conditions, the mass fraction of normal hydrocarbons in the product was 99.43%, and the yield was 38.11%. The inclusion results showed that in the middle and low carbon segments (C₄—C₁₃) of normal hydrocarbons, urea was more inclined to include those with longer carbon chains, with a yield of normal hydrocarbons of C₈ and above higher than 60%, while those below C₆ could be barely included by urea. In addition, when the raw oil contained both olefins and alkanes, the urea inclusion of n-alkanes was better than that of n-alkenes, and the yield difference was about 5.5%. In this oil, oxygenates dominated by linear alcohols were less included by urea, and so more than 95% oxygenate impurities could be removed by urea inclusion method.

The development of accurate mechanistic process models of processes at the molecular radical scale is an important direction in the development of "molecular refining" in the world. The complexity of molecular refining process systems is mainly due to the coupling and multiscale of chemical reaction networks, which poses a challenge to the in-depth understanding of chemical production processes. The key information mining and representation of the complex reaction network can help engineers to understand the process mechanism in depth and realize the transparency of the mechanism. Since the complex reaction networks of oil refining processes have modular and community-based characteristics centered on key reaction substances, this paper adopted the Leiden community detection algorithm to divide the reaction networks of steam cracking into reaction communities at mesoscale. The corresponding key reaction pathways were extracted from the reduced reaction communities at the molecular free radical scale. It provided an interpretable bridge from macroscopic reaction networks to microscopic substance interactions and helped to reveal the knowledge transfer mechanism of the substance transformation process.

The development of high-performance electronic devices requires heat transfer devices with thinner thickness and higher heat transfer performance. Heat pipe relies on the latent heat of internal working medium phase change to transfer heat. It has the characteristics of high thermal conductivity and good temperature equalization effect. It is widely used in the heat dissipation of electronic devices. In this paper, an ultra-thin flat plate heat pipe with a thickness of 0.6mm was fabricated. The interior of the heat pipe shell and the copper wire mesh were hydrophilic modified. The steam channel was processed by the wire mesh to realize gas-liquid coplanar to reduce the flow resistance. A heat pipe performance test platform was built to study the effects of deionized water and ethanol and different liquid filling rates on the heat transfer performance of ultra-thin flat heat pipe under the condition of natural convection cooling. The results showed that the chemical modification improved the wettability of the shell and copper wire mesh to deionized water, and improved the capillary force of the copper wire mesh at the same time, after hydrophilic modification, the thermal conductivity of deionized water heat pipe increased by 19.53% compared with that before modification. The optimum liquid filling rate of the heat pipe filled with the two working fluids was 1.0, and the maximum power allowed to be input was 6W when the maximum temperature of the evaporation section was controlled to be less than 80℃. The heat pipe filled with deionized water showed better thermal performance.

Using the Eulerian multiphase flow model and the evaporative condensation model, a vapor-liquid-solid three-phase flow model of the dynamic pressure mechanical seal lubricating film involving high-temperature vaporization, solid particles, viscosity-temperature effects and Newtonian fluid internal friction effects was established, the variation law of the vapor-liquid-solid flow characteristics of the lubricating film with the working conditions, and the relationship between the vaporization of the lubricating film, the distribution of solid particles and the sealing performance were calculated and analyzed. The research showed that the vaporization of the lubricating film and the distribution of solid particles were mainly located in the groove and weir area, and there was a mutual restraint relationship between the vapor phase and the solid particle phase. Liquid phase vaporization and viscosity drop caused by high medium temperature weakened fluid dynamic pressure, which would cause the high pressure area of the outer groove root to be indistinct or even disappear. The degree of vaporization of the lubricating film decreased first and then increased slowly with the increase of the speed. There was a vaporization-inhibiting speed zone and moves to the high-speed direction with the increase of the medium temperature. The volume fraction of solid particles increased rapidly when approaching the vaporization inhibition speed region. When the medium pressure increased to a certain value, the phenomenon that the volume fraction of solid particles rapidly dropped to near zero occurs, and the higher the medium temperature, the smaller the medium pressure of the rapid drop. When the medium temperature was higher than 423K, the lubricating film opening force, leakage amount, and friction torque all changed from gentle to accelerated changes near the vaporization suppression speed.

The minerals dissolution and precipitation in geothermal water has a significant impact on geothermal resource development. Based on the control equation of water-SiO₂ reaction rate, a thermal-hydraulic-chemical (THC) coupling numerical model of single-well enhanced geothermal system (SEGS) was established. The accuracy of flow heat transfer model and solute transport model was validated by the analytical solution. The coupling relationships between reservoir temperature, SiO₂ concentration, reaction rate and fracture width were simulated and analyzed. Based on the discrete fracture model, the effects of injection mineral concentration and injection flow rate on the heat transfer performance of SEGS were investigated. The results showed that, ① mineral precipitation caused by over-saturated injection and mineral dissolution caused by under-saturated injection occured at a certain distance away from the injection section, the evolution of fracture aperture was distributed as a band at a fracture plane, and the peak value of reaction rate moved to the periphery with time; ② the maximum differences between injection pressures and production temperatures obtained from the coupling model of TH and THC were 2.12MPa and 4.66℃, respectively. Under-saturated injection reduced the injection pressure and accelerated the attenuation of production temperature, while over-saturated injection was the opposite; ③ when the SiO₂ concentration increased by 0.005mol/kg, the average injection pressure increased by 0.5MPa and the average recovery temperature increased by 0.4℃. When the injection flow increased from 8kg/s to 12kg/s, for over-saturated injection, the injection pressure increased by 7.2MPa and the production temperature decreased by 8.58℃ after 30 years; for under-saturated injection, the injection pressure increased by 5.14MPa and the production temperature decreased by 10.43℃.

In view of the fact that few studies have been involved in dual-fluid composite cooling for PV/T(photovoltaic/thermal) collectors to date, this paper carried out comparative experiments between composite cooling and non-refrigerant cooling through two sets of PV/T module test platforms, which were built to study the performance of this module under different flow conditions. The research data indicated that increasing the mass flow rate of air and water synchronously was conducive to improving the electrothermal performance of the PV/T module, with a maximum integrated efficiency of 84.46%; the surface temperature of the glass plate was obviously stratified under the composite cooling mode, and its electrical efficiency was 16.09% higher than that of the non-refrigerant cooling module. The comparison of the experimental data with the simulation results had verified the credibility of the PV/T numerical model, thus paved the way for further simulation and analysis of how design parameters influence the performance of the PV/T module. The simulation results showed that: only by increasing the mass flow of air or water, the overall thermal efficiency and integrated efficiency of PV/T module were improved; increasing the temperature of the imported working medium reduced the electrothermal efficiency of the module; increasing radiation intensity could effectively boost the comprehensive performance of the module.

Solketal is an emerging derivative in biodiesel industry with high value added, which can be used as high-performance plasticizer and gasoline and diesel enhancer. Solketal exhibits several advantages such as low toxicity and degradability. However, efficient and green synthesis of solketal is still a major challenge. The reaction mechanism of acetone to glycerol and the catalyst structure-activity relationship have been critically reviewed. The reaction mechanism of glycerol acetalization mainly includes BAS, LAS, BAS-LAS synergistic and base-acid synergism. Regulation methods of catalysts involves loading metal oxides on the porous materials, treating catalysts with acids/salts and surfactant. Studying the inhibition of catalyst deactivation due to hydration polarization is necessary to improve the anti-salt and anti-impurity ability of catalysts in the future, which could provide ideas for the development of low-carbon green synthesis process of acetone glycerol and its derivatives in the future.

Metal-based catalysts suffer from sintering of metal particles at high temperature, which causes the decline of catalytic performance and even deactivation. Therefore, improving the thermal stability of metal-based catalysts becomes a critical challenge for heterogeneous catalysis. In this review, the two main sintering mechanisms for metal-based catalyst has elaborated, including particle migration and Ostwald ripening. Four approaches to determine the sintering mechanism by particle size distribution, particle growth kinetics, in situ transmission electron microscopy analysis, and experimental and computational prediction were established. Among them, temperature affects the kinetic energy of metal particle, which is the main physical factor for particle sintering, while chemical potential, as one of the chemical factors for particle sintering, is greatly affected by the metal-support interaction. In addition, we summarized the research progress in developing the sintering-resistant catalysts on the basis of metal-support interaction, spatial confinement and other novel structure strategies. Furthermore, the development and goal for the research and construction of sintering-resistant catalysts are proposed from the aspects of catalyst preparation, structure analysis and catalytic performance.

The intrinsic ZnSn(OH)₆ has a wide band gap (about 4.0eV), and the valence band and conduction band position make it have high redox potential, which is conducive to driving the photocatalytic redox reaction. It shows a good application prospect in the fields of environmental purification and energy development. In this review, the crystal structure and surface structure of ZnSn(OH)₆ are introduced according to its physical and chemical properties. Based on the application of ZnSn(OH)₆ in photocatalysis, the modification strategies of ZnSn(OH)₆ are outlined, including defect engineering, element doping, heterojunction establishment and crystal control. Finally, the application of ZnSn(OH)₆ in energy development (hydrogen production and carbon dioxide reduction) and environmental treatment (sewage disposal and air purification) are emphasized. At the same time, it is pointed out that the practical application of ZnSn(OH)₆-based photocatalyst is still in the preliminary stage. In the future, it is necessary to further explore the accuracy of the modification strategy for ZnSn(OH)₆ application requirements, expand its application fields, provide approaches and ideas for follow-up research, and accelerate the process of its industrial application.

Natural minerals have become a hotspot in catalyst research due to their large reserves, rich active components, low price, and environmental greenness. In the paper, rare earth tailings were modified with Cu by immersion-hydrothermal method, and the effect of Cu modification on the catalytic performance of rare earth tailings was investigated by XRD, SEM-EDS, XPS, NH₃-TPD, H₂-TPR and BET. The results showed that the denitrification performance of the rare earth tailings catalysts was substantially improved after Cu modification, and the active reaction temperature window was broadened to 200—350℃. The denitrification efficiency of the catalyst increased and then decreased with the increase of Cu content, and the most obvious performance enhancement was achieved at an amount of 2.5%. Cu modification increased the specific surface area of the rare earth tailings catalyst, and Cu existed mainly as CuO on the catalyst surface which interacted with Fe₂O₃,_{making the binding energies of Cu²⁺, Fe²⁺ and Fe³⁺ shifted significantly. The electron cloud density around Fe ions was induced to decrease, and the strongest interaction between the two in the 2.5% Cu modified catalyst enhanced the redox ability and acid activity center of the catalyst, and the reduction temperature of CuO had stronger influence on the denitrification activity than its oxidation ability, while the oxidation ability of Fe2O3 had stronger influence on the denitrification activity than its reduction temperature. The more mobile adsorbed oxygen on the catalyst surface was favorable for the denitrification reaction.}

The addition of surfactant in the preparation process can affect the morphology and size of photocatalyst nanoparticles, thereby affecting their photocatalytic efficiency. In this work, the Ca-doped β-In₂S₃ photocatalysts with different surfactants were prepared by a hydrothermal method. The physicochemical properties of the prepared photocatalysts were characterized by XRD, SEM, XPS and UV-vis DRS. The results showed that the addition of SDS and CTAB had no obvious effect on the morphology and structure of Ca-doped β‍-In₂S₃ photocatalyst, but the introduction of CHSB and PVP significantly changed its morphology and structure. In particular, the addition of PVP greatly promoted the growth of lamellar structure of Ca-doped β-In₂S₃, showing the richest lamellar structure and the largest specific surface area, which could increase the active sites on the surface of the photocatalyst and improve its photocatalytic performance. The degradation rate of MO could reach 98.38% in 30min. With the increase of PVP content from 0 to 0.022g, the photocatalytic degradation rate was gradually improved, and then continued to increase to 0.033g, the promotion effect was not obvious. Free radical trapping experiments proved that photo-generated holes and superoxide radicals were the main active materials in the photocatalytic process. The degradation mechanism of MO was analyzed by the above characterization methods combined with free radical trapping experiments. This paper could provide a reference for the addition of surfactants in the preparation of semiconductor photocatalysts by hydrothermal method.

Hydrodesulfurization (HDS) evaluation of the industrial Fe-Mo catalyst was carried out by using a micro fixed bed reactor. The influence of constant carbon components (CH₄、C₂H₄、C₂H₆、CO、CO₂) in coke oven gas on the hydrogenation activity, selectivity and carbon deposition were studied. The catalyst was characterized by infrared carbon sulfur analyzer, N₂ adsorption desorption, Raman and TPRS-MS. The results showed that the order of COS, CS₂ and C₄H₄S hydrogenation conversion from easy to difficult was COS>CS₂>C₄H₄S under the carbon-free atmosphere, but the hydroconversion of COS was obviously affected by the carbonaceous atmosphere, which made it difficult to completely remove COSs. The atmosphere also had an impact on the hydrogenation selectivity of sulfide, among which C₂H₄ had the most obvious effect, while CO₂ and CO had the most obvious effect on the yield of H₂S. After 11h stable reaction at 410℃ in different carbonaceous atmospheres, carbon deposition took place on the catalyst, mainly as graphitized carbon, and carbon deposition was the most serious in C₂H₄ atmosphere. The influence order of atmosphere on carbon deposition was C₂H₄>CO₂>CO>CH₄>N₂>C₂H₆.

Isobutyl alcohol can be used to produce aromatics and sulfur free fuel oil (C₈, C{}_{\mathrm{8}}^{+}) through dehydration and oligomerization. It is a new non-fossil process for producing power fuel. In this work, HY zeolites with different acidity and pore structure were characterized by XRD, SEM, NH₃-TPD, Py-FTIR and N₂ adsorption desorption and were used in the dehydration oligomerization of isobutyl alcohol. The effects of acidity and pore structure of the zeolites, and reaction time on the isobutyl alcohol conversion and C₈, C{}_{\mathrm{8}}^{+} product selectivity were investigated. HY zeolite with a SiO₂/Al₂O₃ of 20.9 showed the best catalytic performance, and the isobutyl alcohol conversion and the selectivity of C₈ and C{}_{\mathrm{8}}^{+} reached 94% and nearly 90%, respectively. The mesoporous HY was beneficial to the formation of trimers, and for HY zeolites with similar textural properties, the increase of acid content was conducive to improve the conversion of isobutyl alcohol. The catalytic activity of deactivated catalyst could be recovered by calcination in air. In addition, compared with Hβ zeolite with similar Si/Al ratio and mesoporous properties, HY zeolite had a higher C₈ and C{}_{\mathrm{8}}^{+} product selectivity for isobutyl alcohol oligomerization.

As a high molecular polymer, asphalt has complex composition and structure. Ordinary macro experiments cannot study the changes of its internal structure during self-healing. In order to study and explore the characteristics of self-healing of asphalt binder, this paper analyzed and summarized the micro mechanism of self-healing of asphalt binder from the perspective of polymer. Two kinds of methods of constructing asphalt molecular model were studied, and the difference between asphalt molecular model combination method and asphalt average molecular simulation was pointed out. Four kinds of methods for verifying the rationality of asphalt molecular structure model were proposed, namely asphalt molecular density, radial distribution function (RDF), calculation of solubility parameters and cohesion energy, and glass transition temperature. The mean square displacement (MSD) and diffusion coefficient of asphalt molecules were proposed as evaluation indexes to determine the self-healing degree of asphalt binder. The influencing factors of asphalt molecular self-healing performance were summed up as healing temperature and internal structure characteristics of asphalt, and the problems and development direction of molecular dynamics simulation of asphalt molecular self-healing behavior were also summarized.

As the main component of pavement crack silicone sealing (PCSS) material, the silicone material with highly cross-linked network structure makes PCSS material have excellent adhesion, water resistance, aging resistance, and high and low temperature. Therefore, PCSS material has become one of the important repair materials for pavement crack treatment. This paper reviewed the research progress of pavement crack silicone sealing materials. Firstly, according to the failure causes of PCSS materials, three failure modes of PCSS materials were summarized, namely, low temperature failure, high temperature failure and (rain) driving load failure. Various road performance requirements of PCSS materials to be met were summarized and proposed according to failure modes. At the same time, the preparation methods and research progress of PCSS materials were reviewed. Based on the modification methods of silicone structure, PCSS materials were divided into physical modification and chemical modification. The establishment of PCSS material evaluation method and its shortcomings were summarized. Finally, the development prospect of self-healing silicone sealing materials in the field of crack repair was prospected, which provided some theoretical guidance and technical reference for the application of silicone sealing materials in the field of crack repair.

Glass fiber reinforced resin is the most widely used engineering composite material. Since the end of the 20th century, more and more attention has been paid to the interface bonding between glass fiber and resin matrix. The nanocomposite coating called "sizing" on the surface of glass fiber contributes greatly to the smooth production and application of glass fiber. In addition, sizing serves as a crucial "chemical bridge" for the interface bonding or interaction between glass fiber and the resin matrix. However, the sizing formulations of giant glass fiber manufacturers are highly confidential, and the related industries also lack comprehensive or reliable database on the science and technology of glass fiber sizing, limiting the acquisition the sizing knowledge and effect in composite products for researchers. In this work, the characterization and analysis methods of glass fiber sizing agents were reviewed through extensive comparative analysis of published works, so as to help the R&D and production personnel in composite industry to better understand the role of glass fiber sizing in reinforced composites. In this work, the basic knowledge of glass fiber sizing was introduced first in brief. Then, some typical characterization and analytical methods of sizing were introduced. Finally, the current research status was summarized and the challenges of characterization technology were discussed and prospected.

Microencapsulation of phase change materials (PCMs) provides good sealing protection for PCMs and solves the volume change and leakage problems during phase transition. However, the problems of low thermal conductivity, poor mechanical strength and thermal stability, and single function of microencapsulated phase change materials (MEPCMs) cannot be ignored. MEPCMs modification is an effective way to solve these problems. This review firstly introduced the compositions, structures and preparation methods of MEPCMs. The principles and research progress of modification methods such as multi-core materials, multi-shell layers and hybrid shells were emphatically reviewed. The performance enhancement and function expansion of MEPCMs by different modification methods and materials were outlined, mainly including enhancing their thermal conductivity, thermal storage capacity, thermal stability and mechanical strength to make them multifunctional. On this basis, the development of modified MEPCMs in photothermal conversion was elaborated. The photothermal materials, operating principles and latest progress of photothermal conversion MEPCMs were summarized. Finally, the existing problems and prospects of MEPCMs modification were discussed. It was pointed out that the modification process should be simplified, the development of multifunctional MEPCMs should be increased and the application of photothermal conversion MEPCMs in practical engineering should be promoted.

PU yarn-based flexible strain sensors have the advantages of light weight and softness, good air permeability, excellent mechanical properties, good sensing performance, cheap and easy to obtain, etc., but there are problems of nonlinear relationship between sensitivity and strain range and hysteresis. In this paper, the composition of the carbon nanomaterial/PU yarn-based flexible strain sensor was firstly introduced and the influence mechanism of each component on the sensor performance was analyzed. On this basis, according to the different preparation methods of PU sensor yarns, the research progress of three types of sensors of homogeneous PU yarn, coated PU yarn and structured PU yarn was reviewed. It was pointed out that a reasonable selection of spinning raw material addition, spinning draft ratio, coating binder, thickness ratio of conductive skin layer to non-conductive core layer, effective coverage ratio of conductive skin layer to non-conductive core layer, multi-dimensional conductive network, and novel yarn structure and yarn. New molding technology can improve the sensing performance of PU conductive yarn. Finally, the problems existing in carbon nanomaterials/PU yarn-based flexible strain sensors were analyzed, and the future prospects for high-performance PU basic yarns, high-quality carbon nanomaterials, new processing and integration technologies, and basic conditions that should be met in the process of development and application were analyzed. The key development directions of this paper were prospected in order to provide a reference for the development of high-performance yarn-based flexible strain sensors.

Flexible supercapacitors show potential applications in wearable and portable electronic energy storage devices. Carbon materials usually serve as flexible substrate and conductive active filler in flexible supercapacitors due to their excellent flexibility, high conductivity and large specific surface area. Hence, this paper reviewed three energy storage mechanisms in supercapacitors, the double electric layer, the pseudocapacitor and the hybrid. The latest research progress of carbon materials as flexible substrate and conductive filler was introduced in the following part, respectively. According to three energy storage mechanisms, the analysis of carbon materials as flexible substrate and pseudocapacitance materials can provide not only large specific surface area, but also a large number of active sites for redox reaction. As a conductive filler, it can improve the stability of pseudocapacitance materials and transport channel for electrolyte ions. Finally, the main problems of current electrode design in terms of mechanical properties, preparation methods and evaluation standards were presented.

Paraffin (PA) phase change materials are difficult to emulsify and disperse, and ion crosslinking is used to finalize the design. Based on the hydrophilic and easy ionizing properties of polyacrylic acid (PAA) carboxyl group, the grafted paraffin of low polymerization degree polyacrylic acid (PAA) was designed. The paraffin emulsion was prepared by self-emulsification method. Paraffin solid-solid phase change materials (PA SS-PCMs) were prepared in water medium in a short period. The morphology of PA emulsion and PA SS-PCMS were characterized and analyzed by scanning electron microscope. The molecular structure, crystallization performance and thermal stability of paraffin graft products and PA SS-PCMS were tested and analyzed by infrared spectrometer, X-ray diffractometer, polarizing microscope, differential scanning calorimeter and thermogravimetric analyzer. The results showed that the setting method was universal to different kinds of paraffins, and paraffin solid-solid phase change materials with high energy storage efficiency could be obtained by grafting modification and ion crosslinking. The results indicated that adding 55^# paraffin (PA1) twice, reducing the proportion of PA1 input in the early stage and adding PA1 without participating in the reaction in the later stage, could effectively improve the self-emulsification capacity and phase change energy storage capacity of the graft products. On this basis, PA1 SSt-PCMs with AA∶PA1∶BPO mass ratio of 1.8∶15(10+5)∶0.05 were prepared with a crystallization temperature of 45.52℃ and an enthalpy of crystallization of -182.28J/g. The enthalpy of crystallization loss was 3.05% after 100 cycles with high energy storage density and good thermal storage stability.

NiO was synthesized by a static hydrothermal treatment in the mixed solvent of ethanol and deionized water. Besides, the electrochemical behavior of NiO in the KOH solution and CO₂ adsorption performance were investigated. The phase, morphology, composition and pore structure of NiO were analyzed by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive spectroscopy and N₂ adsorption-desorption techniques. The results showed that NiO was granular mesoporous material and belonged to cubic crystal. In NiO, Ni was in the form of Ni²⁺ and Ni³⁺. A pseudocapacitance behavior was detected in the three electrodes which was made up of the active substance of NiO and the electrolyte of KOH (6mol/L). When the current density was 1A/g and the voltage window was in the 0.1—0.5V range, an initial discharge efficiency of 93.5%, specific discharge capacity of 254.5F/g, the energy density of 5.7Wh/kg and the power density of 200W/kg were achieved. After 1000 cycles, the discharge specific capacity decreased only 3.93%. CO₂ adsorption process on the surface of NiO was in accordance with the Bangham model. At 25℃, the adsorption capacity of 103.2mg/g could be achieved in the gas flow rate of 10mL/min. After 20 cycles, the capacity remained stable.

The electrodeposited PbO₂ coating on stainless steel is feasible to apply on the cathode plate of proton exchange membrane fuel cell, but the PbO₂ coating prepared by the direct current (DC) process has poor compactness and insufficient corrosion resistance. In this paper, the pulse-controlled process of electrodepositing PbO₂ coating on 316 stainless steel was studied, the effects of parameters such as current density, frequency and duty cycle on the growth rate and microstructure were investigated, and the performance of the coating in the fuel cell environment was further investigated. Focusing on the electrochemical performance of PbO₂ coating at high potentials. the microstructure and XRD results showed that the PbO₂ coating by pulse electrodeposition had finer grains and denser structure than the coating by DC. The potentiodynamic polarization results indicated that the corrosion potential of the pulsed coating was slightly higher than that of the DC, and the corrosion current density was reduced by an order of magnitude. In the high potential polarization test, compared with the DC coating, the current density of the pulse process coating was significantly lower, the stability of the coating was significantly improved, the damage degree under high potential was less, and the substrate could be better protected. The polarization test at working potential showed that the reduction of PbO₂ was more serious in the anodic environment, but only a slight reduction occured in the cathodic environment. In a word, compared with the DC coating, the microstructure of the pulse coating was denser and finer, and had good corrosion resistance, especially the better stability at high potential, and it had a better application on the PEMFC cathode plate.

Nitrogen/oxygen co-doped 3D hierarchical porous carbons with ultra large specific surface area were prepared from wheat flour in the presence of potassium oxalate/urea solution on the basis of its good swelling and permeation effects on starch grains. The experimental results indicated that when the mass ratio of wheat flour to potassium oxalate was 1∶1.5, the pore structure and surface physicochemical properties of porous carbon materials could be effectively optimized by adding proper amount of urea as pore forming agent and dopant. The maximum specific surface area of the porous carbon samples prepared was 3192m²/g, and its micropore and mesopore volumes were 1.48cm³/g and 0.55cm³/g respectively. In the three electrode system, the electrochemical analysis results indicated that the specific capacitance of the porous carbon electrode sample KNPC-7.5-7.5 could reach 284F/g with an ideal rate performance when the current density was 0.5A/g. A button-type symmetric supercapacitor was assembled by using KNPC-7.5-7.5 sample as electrode material to evaluate the electrochemical energy storage performance. The sample electrode offered excellent cyclic performance with 95.6% capacitance retention after 5000 times cyclic charge and discharge at a current density of 5A/g. Moreover, the self-made supercapacitor showed a high energy density of 23.7Wh/kg at a power density of 223.6W/kg.

The polyurethane (PU) elastomer with high strength, mild irritation conditions and rapid repair based on the synergistic action of disulfide and hydrogen bonds was prepared. Starting from molecular structure design, poly(propylene glycol) (PPG) was used as a soft segment and isophorone diisocyanate (IPDI) as a hard segment to construct a polyurethane backbone, and then 1,4-butanediol (BDO) and 2,‍2'-diaminodiphenyl disulfide (DTDA) were embedded in the polyurethane backbone as chain extenders. The structure and properties were characterized by infrared spectroscopy, Raman spectroscopy, thermal analysis, mechanical testing and optical microscopy. The effects of the ratio of soft to hard segments, repair time and repair temperature on the mechanical properties and self-healing properties of PU were studied. The results showed that the self-healing polyurethane had high elongation at break of 2398%, fracture strength of 8.84MPa and puncture resistance. At the same time, the PU had excellent self-healing properties under mild stimulation conditions, and its repair efficiency was directly proportional to the repair time and repair temperature. The fracture strength of the specimen with 44.26% mass fraction of hard segment content could be recovered to 92.7% of the original specimen by heating at 70℃ for 3h. Reprocessing tests indicated that PU could also be recycled by hot pressing with a recovery rate of 98.8%. Furthermore, the self-healing PU elastomer could be used as a flexible substrate for wearable sensors to monitor human limb movements.

With China's goal of carbon peak and carbon neutrality in 2020, reducing carbon emissions has become the country's main goal in ecological and environmental governance. Carbon dioxide is the main greenhouse gas and the main form of carbon in the air. In industry, it has the advantages of easy access to raw materials and large storage under natural conditions. If the carbon dioxide in the air can be recycled and prepared into new substances that can be reused through the reaction, it not only provides a new idea for effectively reducing carbon emissions, but also makes the carbon dioxide be effectively utilized. In order to further study the reduction and transformation of carbon dioxide, the main enrichment methods of carbon dioxide in air and their reduction and transformation ideas were described in this paper. According to the requirement of carbon dioxide concentration and the research methods, including direct conversion, electrocatalysis, photocatalysis, artificial photosynthesis and enzymatic method, the research in recent two years was summarized. The preparation methods and research results were reviewed, which provided a further reference for the study of carbon dioxide reduction and utilization.

Now in the context of the novel coronavirus pneumonia outbreak, the control and removal of microbial aerosols has once again attracted academic attention, while conventional air purification methods such as filtration, chemical agents and UV have their own defects and deficiencies. With the advantages of high efficiency, wide spectrum, green, no residue, dynamic continuous disinfection, photocatalysis has broad application prospects. In this paper, the research on the inactivation of microbial aerosols with photocatalysis system is summarized and analyzed from the aspects of the types of photocatalysts, the load of photocatalysts, the light source and the structure and operation of reactors. TiO₂ or its derivative materials are selected as photocatalysts in most studies, and more novel and efficient photocatalysts should be applied. Porous, multi-channel and large surface area catalyst carriers can effectively improve the efficiency of photocatalysis system. The light source still depends on UV light, and the application of visible light needs more research. There are few studies on improving the photocatalysis system by optimizing the reactor structure, and the most commonly used is the ring reactor. Researchers have developed photocatalytic air purifiers or combined photocatalysis systems with indoor air duct systems. In the future, photocatalysis system will become an important means for indoor microbial aerosol control.

Polyethylene terephthalate (PET) are widely used. Waste PET is not easy to degrade in nature and waste PET environmental pollution is becoming increasingly serious. There are some problems in the traditional physical recycling and chemical recycling process such as unstable product performance,complicated technological processes and high equipment requirements.The transformation of waste PET into value-added functional products with excellent performance, powerful functions and wide application scope through physical or chemical process is important technologies to solve the environmental pollution problem of waste PET and realize the sustainable development of resources. In this paper, the preparation methods of porous carbon materials based on waste PET including direct carbonization, activation and template method were systematically summarized. The progress in the applications of these porous carbon materials in the fields of environmental remediation, energy storage and conversion, catalysis, and so on were especially reviewed. In view of the existing problems in studying on preparation and applications of porous carbon materials based on waste PET, important research directions to realize value-added conversion of waste PET and industrial application were proposed, including the technical research of high efficiency classification of plastic wastes and advanced preparation technology with low energy consumption and precise controllability of pore structure, and further study of structure-performance relationship mechanism.

The production of municipal sewage sludge in China is about to reach 90 million tons. Harmless, reduction and resource disposal for them is very urgent. The mass fraction of phosphorus in dried sewage sludge is 2%—6%. The potential is highly great for recycling phosphorus resource from sewage sludge. This not only reduces the consumption of phosphorus ore, but also alleviates global phosphorus crisis. The discussion about the recovery and utilization of phosphorus resource from sewage sludge focuses on five aspects, including sewage sludge disposal technologies, phosphorus content and speciation in dewatering sewage sludge, phosphorus speciation transformation during these thermal treatments (pyrolysis, incineration, gasification, hydrothermal carbonization), phosphorus recovery methods from sewage sludge ash/char and plant absorbability of phosphate minerals. It is also comparatively analyzed in detail that the effect of different factors including temperature, additive components and blending fuel types on phosphorus speciation in thermal treatment products. Finally, it is summarized and contrastively analyzed that the recovery processes of phosphorus from thermal treatment products and different factors influencing on the phosphorus recovery. Meanwhile, the plant availability for the recovered phosphate minerals were also discussed. This review could provide some suggestion for the resource utilization of phosphorus from sludge in China in the future.

The large-scale utilization mode of renewable energy based on "green electricity+green hydrogen" is an important measure to achieve the carbon neutrality. However, the current hydrogen storage and transportation technology cannot meet the large-scale and cross-temporal needs of this utilization mode. Hydrogen storage by liquid polycyclic aromatic hydrocarbons is considered to be the most likely technology to achieve large-scale safe and efficient off-site hydrogen storage and transportation. This article introduces the basic principle of polycyclic aromatic hydrocarbon liquid organic hydrogen storage technology and the physicochemical properties of common liquid organic hydrogen carriers, analyzes the key parameters of organic hydrogen carriers, explains the intra-ring and inter-ring dehydrogenation reaction mechanism of polycyclic aromatic hydrocarbons from the perspective of steric hindrance, and summarizes the further research progress on the dehydrogenation catalysts from the aspects of active component dispersion, surface charge effect, hydrogen overflow and low coordination number. The technical difficulties such as the high dehydrogenation temperature, low cyclic dehydrogenation rate and high catalyst cost and the future application scenarios and development directions such as the energy optimization and catalyst modification are prospected.

Anaerobic digestion (AD) is a conventional technique in antibiotic organic waste treatment. However, high concentration of antibiotics might threaten the activity of microbial community, thus weakening the anaerobic digestion performance and antibiotics degradation. In recent years, anaerobic digestion of organic waste containing antibiotics via conductive materials (CM) addition has been enhanced, and the efficiency of organic resources recovery has been further improved. Based on the current consumption of antibiotic and their effects on AD progress, the review analyzed the antibiotics removal mechanism in AD, and especially emphasized the application and mechanism of iron-based and carbon-based materials on improving antibiotic-stressed AD performance. The results indicated that CM could improve the performance of AD and reduce environmental risks by enhancing interspecies electron transfer, enriching functional microorganisms, and decreasing antibiotics and antibiotic resistance genes in the AD system. Finally, the future directions of conductive materials strengthening technology were discussed from the construction of biological information network, the development and optimization of new material, and the application in multi-pollutant treatment.

The low degradability of waste plastics will continue to pollute the environment, and the spread of the COVID-19 has exacerbated the use and accumulation of plastics, and thus the efficient treatment of waste plastic resources has become an urgent technical problem to be solved. By analyzing several mainstream waste plastics treatment technologies, it was clear that resourceful and high value-added utilization technology was the most competitive and environmentally friendly waste plastics treatment route in the market. The research progress of high value-added utilization technology of waste plastics at home and abroad in recent years were reviewed. The development and variation of conventional thermal cracking technology were discussed. Through this route, the highest yield of waste plastics into fuel products can reach 97%—98%. It was pointed out that the conversion of waste plastics into jet fuel, high value-added chemicals and functional materials for special applications through chemical, catalytic and biological technologies was the mainstream research direction and development trend in this field. Among them, the yield of conversion to high value-added monomer could reach more than 97%, so as to realize the upgrading of plastic waste from the primary treatment stage of "waste clearance" to "turning waste into use" and "turning waste into treasure", and help China achieve the goal of "double carbon"。

Cost-effective capture of SO₂ and CO₂ from flues gas is still an ongoing challenge to the global ecological environment. Adsorption separation technology with low energy consumption is a promising gas capture technology but porous adsorbents with high capacity, high selectivity and good stability are very scarce. Herein a stable porous organic polymer (named PPN-1) by the reaction of isatin with triptycene under superacidic condition was synthesized. The ionic porous organic polymer was achieved by quaternization of PPN-1 with methyl iodide and then treated with KOH solution for exchange of I^- with OH^- to obtain PPN-1-OH. PPN-1 and PPN-1-OH had high affinity toward SO₂ and CO₂ due to their suitable BET surface areas, considerable microporous structures and abundant electron-rich nitrogen and oxygen atoms. Interestingly, PPN-1-OH possessed an ultra-high SO₂ capture performance (13.09mmol/g) at 0.1MPa and 298K, which exceeded previous reported porous adsorbents. Moreover, an excellent SO₂ dynamic adsorption capacity of 1.81mmol/g and SO₂/CO₂ selectivity (211) in ternary gas mixture (SO₂/CO₂/N₂=0.2/9/90.8, v/v/v) was achieved in PPN-1-OH based on column breakthrough experiments. The theory simulation revealed that the introduction of hydroxyl groups into the micropore channels of PPN-1-OH could significantly enhance the interaction between SO₂ and PPN-1-OH and improved the SO₂ capture capacity and selectivity.

Hydrothermal filter cake, produced from 90% food waste digestate residues and 10% incineration fly ash, was pyrolyzed to prepare biochar (DFC). The DFC was used together with sludge biochar (SSC) as raw materials for proportioning and sintering to prepare high-strength building ceramsite to realize the resource utilization of solid waste. The performance testing was according to national standard GB/T17431.1—2010. BCR morphological analysis and potential ecological risk indexes were used to assess its safety. The results showed that all the performance indicators of the building ceramsite prepared by DFC and SSC in the ratio of 25%∶75% at a sintering temperature of 1050℃ comply with the national standard GB/T17431.1—2010, including compressive strength greater than 5.85MPa (density class 900), bulk density less than 1050kg/m³, apparent density less than 2000kg/ m³, chloride content less than 0.02%, and sulphide and sulphate content less than 1%. The leaching toxicity of heavy metals was lower than the threshold values of national standard GB 5085.3—2007, and the main fraction of Cr, Ni, Cu, Zn, As and Pb is F4 fraction, accounting for more than 70% of the total, while the potential ecological risk index indicates that the safety of heavy metals in building ceramics was high and belongs to low risk. Through economic calculation, it could be seen that every 1t of construction ceramics produced could generate an additional income of about 2000—2500CNY, so this study had a broad application market and prospect, and was also one of the effective ways to achieve the resourcefulness, reduction and harmless disposal of DR, FA and SSC.

Polyester fiber is an important source of microplastics in wastewater treatment plants, but the effect of polyester fiber on wastewater biological treatment is not clear. In this study, the response of polyester fiber microplastics with different concentrations (0, 10mg/L, 1000mg/L) of 1mm in length and 20µm in diameter to the reactor performance and microbial community structure was investigated in laboratory-scale sequencing batch reactor (SBR). The results showed that polyester fiber microplastics accumulated continuously in the sludge, but the treatment performance of the reactor was not significantly affected, with high purification capacity. At the same time, the continuous exposure of polyester fiber microplastics made the sludge settling performance worse and inhibited the secretion of extracellular polymeric substances (EPS). Under the stress of high concentration of polyester fiber microplastics, the abundance and diversity of sludge microbial community increased. Dokdonella was the most abundant denitrifying bacteria in activated sludge, and the relative abundance of denitrifying bacteria increased with the increase of polyester fiber microplastic concentration. This study showed that filamentous polyester fiber microplastics had no significant effect on the biological treatment performance of sewage, but had certain selectivity to sludge microbial community in a certain period.

Dioxin (DXN) produced by municipal solid waste incineration (MSWI) processes is a highly toxic pollutant with unclear mechanism up to date. It is important to understand the boundary conditions of the formation, combustion and regeneration of DXN in the grate furnace for reducing pollution emissions. In this paper, a numerical simulation method of DXN emission concentration in grate furnace incineration processes for municipal solid waste was presented. First, according to the MSWI processes flow of a typical grate furnace, the mechanism of DXN-related reactions such as solid-phase combustion, gas-phase combustion, high-temperature heat exchange and low-temperature heat exchange in the incinerator was described. Then, according to the above divided areas, a numerical simulation model combined with the relevant parameters of actual MSWI process was constructed. Finally, a univariate analysis was performed based on the reactant concentrations characterized by the flue gas split fraction and the reaction temperatures in different regions to obtain the boundary conditions for the DXN concentration at G1. The effects of split fraction and reaction temperature on the DXN concentration at G1 were analyzed based on orthogonal experiments, and the optimal parameter combination was obtained. The validity of the model was proved by numerical simulation analysis and verification based on the actual data of a MSWI power plant in Beijing. It will provide support for the subsequent optimal control of DXN emission concentration at G1.

The harmless treatment of fracturing flow-back fluid is one of the urgent problems to be solved in the green development of shale gas, which is also an important part of realizing the goal of "carbon peaking and carbon neutrality". In this paper, the hydrophilic hydrogel with double network pore structure was prepared from natural polymer material NPG and polyvinyl alcohol (PVA), with polypyrrole (Ppy) as solar absorber. Taking solar energy as driving force, the interface solar evaporation technology based on the hydrogel was applied to core desalination and pollution reduction of fracturing flow-back fluid, achieving the low energy consumption and standard discharge treatment of fracturing flow-back fluid. The experimental results showed that under a standard solar intensity (1kW/m²), the maximum evaporation rate of fracturing flow-back fluid treated with SH was 3.59kg/(m²·h), and the average solar evaporation efficiency was more than 96%. After desalination and sewage treatment, the total dissolved solids of the flow-back fluid was less than 150mg/L, the concentration of various salt ions was significantly reduced by 3—4 orders of magnitude, and the removal efficiency of TOC content was as high as 87.1%. At the same time, hydrogel had good salt resistance and self-cleaning function, which can ensure its long-term and continuous use.

Anaerobic ammonia oxidation (Anammox) process has been rapidly developed due to its excellent nitrogen removal performance and low consumption, but the lack of sufficient Anammox sludge limits the practical application. Although adopting Anammox sludge containing anaerobic ammonium oxidizing bacteria (AAOB) as seed sludge can shorten the start-up period, it is impractical since the Anammox sludge is expensive. Therefore, in this study, the feasibility of starting Anammox process by adopting municipal waste sludge as seed sludge was explored, and the performance was optimized by adjusting the operational parameters. The results showed that the Anammox could be successfully started-up after 59d's operation in three phases (aerobic+anaerobic, aerobic with temperature control and anaerobic with temperature control), and the Anammox showed strong nitrogen removal on the 33rd day. The stirring period of 10h was the shortest that the Anammox could endure, and the maximum total nitrogen removal rates could reach 0.555kg/(m³·d). After the reactor ran stably, the microbial diversity decreased, while the nitrogen removal related bacteria was significantly enriched, with the relative abundances of Candidatus_Kuenenia, Denitratisoma, Arenimonas, and Truepera increased from 0.8%, 0.9%, 3.2%, and 4.0% to 20.4%, 15.2%, 10.1%, and 8.9%, respectively. Adopting municipal waste sludge as the seed sludge for Anammox could solve the difficult start-up problem of Anammox, as well as provide a new way for treating excess sludge.

The anaerobic/anoxic/aerobic-aerated biological filter (A²/O-BAF) process was used to treat low-C/N municipal sewage, the nitrogen and phosphorus removal efficiency of the process was studied when the reflux ratio of nitrification solution was 0, 50%, 100%, 150% and 200%. The results showed that when A²/O operated with the sludge retention time (SRT) being 15d, the hydraulic retention time (HRT) being 10h, and the dissolved oxygen (DO) in the aerobic stage being 2.0mg/L, BAF operated under the conditions of HRT of 3h, aerobic/anoxic exposure time ratio of 50min∶10min, and nitrification solution reflux ratio R of 200%, and the concentrations of COD, TN, NH₄⁺-N and PO₄^3--P in the influent were 232.61mg/L, 53.99mg/L, 52.20mg/L and 5.54mg/L, respectively, the concentrations of COD, TN, NH₄⁺-N and PO₄^3--P in the effluent of the system were 34.11mg/L, 12.44mg/L, 1.01mg/L and 0.34mg/L, respectively, and the nitrite accumulation rate (NiAR) was as high as 95.20%. After the effluent NO₂^--N returned to the A²/O anoxic section, the PO₄^3--P content of the effluent in the anoxic section dropped to 2.68mg/L, denitrifying phosphorus removal (DPR) contributed 75.42% to the removal of PO₄^3--P in the system. Batch tests showed that the phosphorus release of phosphorus removal bacteria in A²/O reactor reached 36.35mg/L after anaerobic treatment for 120min. Under anoxic conditions, the amount of phosphorus absorbed in the reaction with NO₂^--N as electron acceptor was 26.28mg/L, and the phosphorus absorption rate was 72.30%. Denitrifying phosphorus removal bacteria (DPB) with NO₂^--N as electron acceptor accounted for 72.91% of the total phosphorus removal bacteria.

Along with the energy revolution and the advent of the hydrogen produced by electric power, the raw materials and technology for ammonia synthesis are constantly changing. In the context of the revolution of the hydrogen energy industry, the ammonia synthesis industry using hydrogen from water electrolysis in China is not easily constrained by capacity, quota, feedstock and resources, resulting in constructing the largest industrial chain of water electrolysis production and utilization of hydrogen in China. Ammonia synthesis will also transition from traditional hydrogen production from fossil feedstocks to ammonia synthesis from water electrolysis. In addition to being used for the production of fertilizer, ammonia synthesized from green power water electrolysis is expected to replace heavy oil for ship fuel, and to be used for energy storage and peak regulation in coal power plants to replace coal collaborated with the reducing carbon for the production of urea. The application scenario for ammonia synthesis will also shift from traditional synthetic ammonia urea plants from fossil feedstocks to hydrogen production from photovoltaic or wind power plants to produce ammonia, and the capture of carbon dioxide from coal power plant flue gas could produce ammonia to generate renewable urea. Hydrogen production from water electrolysis in oil and gas fields to produce ammonia can realize coupled co-production of electricity-hydrogen-ammonia above ground and oil and gas underground. Along with the changes and progress of hydrogen production from photovoltaic or wind power and ammonia synthesis technology, new challenges will be emerged, such as ammonia transportation, oxygen consumption by water electrolysis and steam consumption by ammonia synthesis.