Reviews

• Research progress in advanced manufacturing of high-purity electronic chemicals and trend of industry-education integration

  WU Chaoyan¹; WEI Chenjun²; YANG Lifeng²; SUO Xian³

  High-purity electronic chemicals are specialized in semiconductors, flat-panel displays, photovoltaics and other advanced industries. It raises high requirements on both high purity and high quality, yet encounters the low localization rates in China. This review uncovers the kinds, functions, preparation and quality requirements of electronic chemicals, such as electronic gas, wet electronic chemicals, photoresist, and highlights the content requirements of purity and trace impurities of critical electronic chemicals. Moreover, this review provides the analysis of industrial scale, competitive landscape, and industry barriers of electronic chemicals in domestic and international markets. It summarizes the research progress of separation technologies (e.g. subboiling distillation, reactive distillation, adsorptive separation, membrane separation) in preparing high-purity electronic chemicals. Furthermore, it highlights the challenges of trace impurities removal in electronic chemicals, and provides the systematic discussions about the mechanisms and advantages/disadvantages of various separation technologies, and the structure-property relationship between separation materials (e.g. adsorption, membrane) and metal ion removal performance. In response to domestic production of electronic chemicals, the review concludes the critical technological challenges that are yet to be addressed in the purification and advance manufacture of electronic chemicals, as well as the importance of integrated development of education, science and technology, and talents in boosting the development of electronic chemicals.

  2025 04 [Abstract][OnlineView][Download 3113K]
  

Chemical Engineering Thermodynamics and Fundamental Data

• Study on kinetics and mechanism of the synthesis of <i>N</i>-benzylnonanamide catalyzed by 3-NPBA-TMPDA

  YU Yanjie; ZOU Shuai; ZHONG Xinle; WANG Jinyu; FANG Kai; XUE Tian

  <i>N</i>-benzylnonanamide and its analogues have wide applications in various fields of medicine, biological control, and tear gas weapons. There are some problems in the synthesis process of these compounds, such as harsh conditions, corrosive and toxic activation reagents. To solve these problems, a novel reaction system was constructed using nonanoic acid and benzylamine as raw materials, with 3-nitrophenylboronic acid (3-NPBA) and <i>N,N,N',N'</i>-tetramethylpropylenediamine (TMPDA) as synergistic catalysts. Aiming to accumulate further knowledge and expertise, the synthesis process and reaction kinetics of <i>N</i>-benzylnonanamide were explored, along with an exploration of the underlying reaction mechanism. The results show that the activation energy of <i>N</i>-benzylnonanamide synthesis catalyzed by the synergistic catalysis of 2.5% 3-NPBA+2.5% TMPDA (molar fraction) is 87.88 kJ·mol^-1 fitted by first-order reaction kinetics. A possible synthesis pathway for <i>N</i>-benzylnonanamide is proposed as follows: 3-NPBA and TMPDA react with nonanoic acid through dehydration to form a six-membered ring intermediate, which then reacts with benzylamine to form the amide. TMPDA, acting as a Lewis base, donates an electron pair to the boron atom of 3-NPBA, stabilizing the intermediate. Meanwhile, during the configuration transition of the intermediate, the nitrogen atom of TMPDA forms a hydrogen bond with the hydrogen atom of benzylamine.

  2025 04 [Abstract][OnlineView][Download 4497K]
  

Chemical Engineering Thermodynamics and Fundamental Data

• Study on the heat transfer performance of tubular reactors under continuous flow steady-state conditions

  SHEN Yang^1;3; CHEN Bingbing^1;2;3; CHEN Lyuming^1;3

  Continuous flow reactors are widely used in nitration reactions due to their efficient and flexible operating characteristics. The research on their heat transfer performance is of great significance for optimizing the reaction process, improving production efficiency and ensuring safety. In order to study the heat transfer characteristics of the continuous stirred tubular reactor with jacket cooling, this paper used the wall method to measure the convective heat transfer coefficient of the reactor, and utilized the numerical simulation method combined with relevant Computational Fluid Dynamics (CFD) software to conduct a detailed study on the relationship between the turbulent characteristics and heat transfer of the reactor. In addition, a comparative analysis with the traditional Wilson plot method was also carried out. The results show that the wall method can measure the convective heat transfer coefficients of the reactor and the jacket quite well, and the used CFD model can also effectively simulate the heat transfer process when the reactor is in a dynamically stable state. The maximum temperature error between the simulation and the experimental monitoring points is 3.71%. The error between the convective heat transfer coefficient on the inner side of the tubular reactor measured by the wall method and that obtained from the CFD simulation results is 4.53%, which proves the accuracy of the wall method. However, the error between the convective heat transfer coefficient of the jacket measured by the Wilson plot method and the simulation result is 32.07%. The research conclusions provide a reference for the optimization design of the heat transfer performance of the tubular reactor under the continuous flow steady-state working condition.

  2025 04 [Abstract][OnlineView][Download 14856K]
  

Chemical Engineering Thermodynamics and Fundamental Data

• Structural optimization and performance analysis of single-pump suction downhole hydrocyclone

  XING Lei^1;2;3; LIU Chang¹; JIANG Minghu^1;2; ZHAO Lixin^1;2; GAO Yang⁴; LI Xinya¹; GUAN Shuai¹

  In order to adapt to the single-pump suction single-well injection-production technology and reduce the cost of downhole oil production and injection equipment, a single-pump suction downhole hydrocyclone was proposed. Combined with the experimental design, numerical simulation, and test research methods, the significant structural parameters of the hydrocyclone were analyzed and optimized, the mathematical relationship model between the structural parameters and the separation efficiency was established, the matching scheme of structural parameters was presented, and the effects of operating parameters on the separation performance of hydrocyclone were analyzed. The results show that the separation efficiency of the hydrocyclone improves from 91.2% to 99.3% after structure optimization. When the split ratio is 40%, the oil volume fraction is 1%, and the inlet flow rate is 5 m³·h^-1, the optimal separation efficiency of 99.83% is achieved. The numerical simulation results are in good agreement with the experimental results. This study can provide technical support for the implementation of single-pump suction single-well injection-production technology.

  2025 04 [Abstract][OnlineView][Download 9614K]
  

Chemical Reaction Engineering

• Parameter optimization of hydrogen purification reactor parameters based on metal hydrides

  HUANG Xianchun¹; WU Zhen¹; ZHANG Zaoxiao^1;2

  Metal hydrides Adsorption Purification (MHAP) is regarded as an effective method for hydrogen separation and purification due to the selective chemical adsorption of hydrogen. This paper investigated the optimal selection of materials for MH reactors, from the perspective of materials to operational conditions. The study collated and analysed the hydrogen storage performance of materials in a mixture of impurities, and identified a reliable set of MH materials. The hydrogen absorption and discharge reaction thermodynamics of the materials were determined by PCT experiments, and the control equations and coupled models were obtained by considering the complex physical conditions of heat transfer and flow in the reactor. The design and operational parameters of the reaction vessel were further investigated through the coupled model, with the aim of determining their impact on the purity and loss of hydrogen in the process. The simulation results indicate that, at a temperature of 353 K, a flow rate of 0.05 kg·m^-2·s^-1 results in a hydrogen purity of 99.999% at the outlet within 505 s.

  2025 04 [Abstract][OnlineView][Download 3566K]
  

Biochemical Engineering

• Response surface optimization of purification process of Lanzhou lily polysaccharide by macroporous adsorption resin and its activities

  LIAO Wenzhu^1;2;3;4; KANG Shuhe^1;2;3;4; LI Li^1;2;3;4; YUAN Mengyao^1;2;3;4; AN Lili^1;2;3;4

  The process conditions for purifying crude polysaccharides from Lanzhou lily were optimized using macroporous adsorption resin, and the whitening, moisturizing, and hygroscopic activities of both crude and purified polysaccharides were evaluated. Through static experiments, DM301 was selected as the optimal resin. Based on dynamic experiments, the weighted comprehensive score (including decolorization rate, protein removal rate, and polysaccharide retention rate) was used as the response value to optimize the optimal process conditions for DM301 purification of lily polysaccharides using response surface methodology. The whitening activity was evaluated by the inhibition of Polysaccharide on monophenolase and diphenolase. The moisture retention and hygroscopic activities of the samples were investigated at 22℃ and relative humidity of 11%, 43%, 81% and 95% within 24 hours. Under the conditions of a sample concentration of 4.30 mg·mL^-1, eluent volume of 0.70 BV, flow rate of 1.36 BV·h^-1, and sample volume of 1.0 BV, the comprehensive score reaches 63.99%±0.02% (<i>n</i>=3), which is close to the predicted value, indicating that the established mathematical model is reasonable. The purified polysaccharides exhibited good whitening activity, which IC₅₀ values for the inhibition rates of tyrosinase monophenolase and diphenolase are 3.52 mg·mL^-1 and 2.79 mg·mL^-1, respectively. At 22℃ and four humidity conditions, both crude polysaccharides and purified polysaccharides exhibit excellent moisture absorption properties (with a 24-hour moisture absorption rate greater than 100%). Purified polysaccharides and their mixtures have high moisturizing properties (24-hour moisturizing rate greater than 97.5%). The optimization of the purification process of crude lily polysaccharides using macroporous adsorption resin combined with response surface methodology is stable and feasible, providing a theoretical basis for the effective purification of lily polysaccharides.The whitening, moisturizing, and hygroscopic activities of purified lily polysaccharides have been enhanced, providing experimental basis for the development of Lanzhou lily polysaccharides.

  2025 04 [Abstract][OnlineView][Download 4051K]
  

Chemical Technology

• A process study on one-step preparation of methyl lactate from sucrose alcoholysis catalyzed with In-TS-1

  LYU Xilei^2;3; JIANG Yuxi¹; NING Shuyu^2;3; REN Aotian¹; QIN Wenqi¹; LYU Xiuyang¹

  Polylactic acid (PLA) is a commercially available bio-based polymer, but the price is high. So, the development of inexpensive monomers, lactic acid (LA) is crucial. The chemical catalytic conversion of sugars into methyl lactate (MLA) is a route with great potential. Compared to crystalline fructose, which is used as raw material in most studies, sucrose is more abundant and cheaper, and using sucrose as a raw material can significantly reduce the production cost of MLA. This work studied the one-pot synthesizing of MLA from sucrose catalyzed with In-TS-1. The Ti/Si molar ratio was optimized, and a Ti/Si molar ratio of 0.015 was found to be optimal. The optimal reaction condition was determined: 10 g·L^-1 sucrose was catalyzed by In-TS-1, whose weight was 50% of sucrose at 170℃ for 18 hours, and the yield of MLA was 55.4%. It is found that a certain amount of water can improve the yield of MLA, and when the water content is 4%, the combined yield of MLA and LA can reach 61.7%. In future production, it's promising to use sugarcane juice as a raw material for continuous production of MLA. The research provides important basic data for the production of MLA from sucrose.

  2025 04 [Abstract][OnlineView][Download 2052K]
  

Process Systems Engineering

• Operational flexibility oriented working fluid selection for organic Rankine cycles

  WANG Yihao; ZHANG Yuxin; ZHU Lingyu; WANG Jiayuan

  The selection of working fluids is crucial for organic Rankine cycle (ORC) design, which has traditionally focused on achieving optimal performance at the design point, while overlooking potential performance degradation caused by deviations from nominal operating conditions. This work developed an operational flexibility analysis framework to facilitate optimal process design and working fluid selection by explicitly considering environmental uncertainties. The framework was based on ORC off-design models to capture potential deviations in process performance from that at the design point. The volumetric flexibility index was adopted to quantify the size of the operational feasible region in the uncertain parameter space. The application of the analysis framework was demonstrated on an ORC-based flue gas heat recovery system. The results show that the choice of working fluid impacts operational flexibility and can be correlated with its boiling point.

  2025 04 [Abstract][OnlineView][Download 6186K]
  

Process Systems Engineering

• Cyberattack path identification and risk analysis of chemical process industrial control system

  LI Susu¹; WANG Haiqing¹; ZHANG Yutao²; CAO Guangkuo¹

  To identify and quantify the potential impacts of cyberattack on industrial operational systems, a Process Bayesian Network (PBN) model was proposed, integrating Process Hazard Impact Analysis (PHIA) and Bayesian Network (BN) theory. The model first identified key risk factors and assessed the potential impacts of cyberattack on the process system, then incorporated the Leaky Noisy-OR (LNOR) logic to establish a probabilistic hybrid quantification framework. Combined with an optimized Expectation Maximum (EM) algorithm, the model addressed parameter uncertainty in traditional methods. Applied to a Continuous Stirred Tank Heater (CSTH) system, the PBN model updated fault probabilities under attack scenarios and evaluated performance using Path Coverage Rate (PRC). Results show that the highest risk propagation path occurs under combined attack, with PRC significantly improving compared to traditional attack tree models, enhancing network attack path identification and risk assessment for optimal prevention strategies.

  2025 04 [Abstract][OnlineView][Download 2718K]
  

Process Systems Engineering

• Renewable energy-driven methanol modular production supply chain optimization strategy based on information gap decision theory

  LI Yang; WU Le; DING Xin; ZHENG Lan; WANG Yuqi

  Considering the methanol demand uncertainty on the influence of methanol modular production supply chain, on the basis of certainty renewable energy driven methanol modular production supply chain optimization model, information gap decision theory was introduced. Two uncertain optimization models were constructed for the cost of capital input and operation process, respectively focusing on the robustness and opportunity of scheduling decision. Finally, the methanol modular production supply chain scheduling scheme under different risk attitudes was obtained through case analysis, in which the reliability and effectiveness of the model were verified. The results show that the risk avoidance methanol modular production supply chain can make the cost no higher than the expected cost, while the risk pursuit can exploit the favorable uncertainty and cost the expected cost lower.

  2025 04 [Abstract][OnlineView][Download 1247K]
  

Process Systems Engineering

• Fault detection in industrial processes based on feature fusion and temporal convolutional autoencoder

  ZENG Fengrong¹; SUN Huanqi¹; XIONG Weili^1;2

  In order to solve the problem of multi-scale time series feature extraction of industrial process data, a fault detection method based on feature fusion and temporal convolutional autoencoder was proposed. Firstly, the multi-layer temporal convolutional network structure was used to extract features from the input time series at different scales, and a multi-scale temporal convolutional autoencoder was constructed. Secondly, a feature fusion module based on efficient channel attention was designed, which was added to the temporal convolutional autoencoder through jump joining and connected the temporal series features of different scales across channels. It generated corresponding weights to weight and fuse the features, so as to capture richer temporal information and enhance the model’s discrimination between normal sequence and abnormal sequence reconstruction error. Finally, the statistics were established by reconstructing the error, and the kernel density estimation was used to determine the control limit to realize fault detection. The proposed detection method is applied to numerical cases and Tennessee-Eastman process, and the experimental results show that the proposed method has good fault detection performance, which can provide a certain reference for fault detection in complex industrial processes.

  2025 04 [Abstract][OnlineView][Download 3368K]
  

Process Systems Engineering

• Combined cycle utilizing LNG cold exergy and nuclear industry waste heat

  DONG Ying¹; ZHAO Chunli¹; WANG Guofu¹; WANG Huaqiang²; ZHAO Pengyue¹; GAO Shenqi¹

  In order to investigate the cold energy of liquefied natural gas (LNG) and nuclear industrial waste heat efficient utilization, two-stage tandem cycle system (TTC) and two-stage parallel cycle system (TPC) were established. Effects of condensation temperature and LNG vaporization pressure on system performance were analyzed. Six working fluids were selected as candidates, with the objective function of maximizing net power output, genetic algorithm was utilized to optimize the system parameters. The results show that there exists a first-stage and second-stage condensation temperature making the performance of the TTC and TPC system optimal. The optimal working fluids for TTC and TPC systems are C₂H₆+C₂H₄F₂ and C₂H₄F₂+<i>i</i>-C₄H₁₀ , respectively. In optimal conditions, the TTC system demonstrates higher net output power, thermal efficiency and exergy efficiency, while the TPC system required heat exchange area has significantly increased, which may have an impact on system economy.

  2025 04 [Abstract][OnlineView][Download 1295K]
  

Material Science & Engineering

• Preparation and properties of quaternary phosphonium salt containing poly-acrylic emulsion

  WANG Lingxiao; XU Guilong; TANG Min; LIANG Yun

  To solve the problems of migration, precipitation and poor antibacterial effect of antibacterial agent added to poly-arylic resin, a quaternary phosphonium salt antibacterial monomer—methacryloyloxypropyl triphenylphosphonium bromide (Br-MAP) was synthesized and used to synthesize quaternary phosphonium salt containing poly-acrylic emulsion. The quaternary phosphonium salt monomer and poly-acrylic emulsion were respectively characterized by ¹H-NMR and ATR-FTIR. Effects of antibacterial monomer contents on the emulsion polymerization stability and the thermal stability, film properties and antibacterial properties of poly-acrylic emulsion resin containing quaternary phosphonium salt were evaluated by TGA, film property test and agar plate diffusion method. The results show that with the increase of the content of Br-MAP, the polymerization stability of emulsion is improved, the particle size of emulsion becomes smaller, while the water absorption of film increases and the thermal stability decreases. When the content of Br-MAP respectively is 2% and 6%, the antibacterial rate against <i>Staphylococcus</i> and <i>Escherichia coli</i> reachs 99.99%.

  2025 04 [Abstract][OnlineView][Download 5946K]
  

Material Science & Engineering

• Effect of benzoxazine resin on the carbonization of ABS resin and its flame retardant modification

  PING Chenhui^1;2; YAN Hongqiang²; GUO Zhenghong²; LI Juan²; TONG Zaizai¹; FANG Zhengping²

  Aiming at poor carbonization of ABS resin, different structures of benzoxazine monomers (BOZ) were blended with ABS resin compounded with the flame retardant bisphenol A diphenyl phosphate (BDP) and the synergist zinc borate (ZB), and the effects of different structures of BOZ monomers and its formulation with BDP and ZB on the flame retardant and mechanical properties of ABS were also studied in order to achieve efficient halogen-free flame retardancy of ABS resin. The experimental results showed that the combination of BOZ, BDP, and ZB could effectively improve the carbonization of ABS resin and demonstrate excellent synergy in flame retardant modification of ABS resin. The LOI of ABS/10C/15B/2ZB reached 34.4%, and PHRR, THR, AEHC, TOC, and TSR decreased by 45.4%, 22.8%, 23.2%, 21.9%, and 7.7%, respectively, finally FPI and FGI also showed significant improvement. At the same time, its tensile strength also increased to 40.2 MPa, which was slightly higher than that of pure ABS resin (39.9 MPa). Therefore, the combination of BOZ with BDP and ZB can achieve a synergistic improvement in flame retardancy and mechanical properties of ABS resin.

  2025 04 [Abstract][OnlineView][Download 2991K]
  

Environmental Chemical Engineering

• Degradation of high-salinity phenol containing wastewater and resource utilization of salt components in ionic membrane electrolysis process

  HE Wenqi¹; ZHAO Jingwei²; LAN Peiqiang³; YAN Zhaochao¹; NI Jie²; WEI Yanfei³; HUANG Mei¹

  If high-salinity organic wastewater is discharged without effective treatment, it will cause environmental pollution and waste of inorganic salts. In the context of carbon neutrality and peak carbon dioxide emissions, the "zero discharge" of high-salinity wastewater and the high-value reuse of salt have become the research focus of high-salinity wastewater treatment. As the efficient removal of organic pollutants from high-salinity wastewater is a prerequisite for achieving desalinated water reuse and the utilization of salt resources in wastewater, MOFs-derived catalyst FeCo-C/N was prepared. Then the FeCo-C/N+O₃ catalytic oxidation system was applied to treat high-salinity phenol-containing wastewater with a NaCl concentration of 310 g·L^-1 and a total organic carbon (TOC) content ranging from 20 to 60 mg·L^-1. Due to the oxidation reaction, the removal rate of TOC reached 65.1% to 88.2%, resulting in a residual TOC content in the wastewater of less than 10 mg·L^-1, which meets the quality requirements of inlet saltwater for the ionic membrane-based chlor-alkali process. Subsequently, an ionic membrane electrolysis test was conducted on the oxidized high-salinity wastewater to ensure that the NaCl concentration in the dilute brine from the anode was between 200.0 and 210.0 g·L^-1, while the NaOH concentration from the cathode was between 32.0% and 33.5%. After 336 h of electrolysis process, the current efficiency and power consumption per ton of alkali were 96.8% and 2 167.0 kW·h, respectively. These experimental results indicate that the treated high-salinity phenol-containing wastewater exhibits stability and economy during the ionic membrane electrolysis process, suggesting its broad application prospects in high-salinity wastewater resource utilization. These results serve as a guide for the large-scale application of high-salinity organic wastewater as raw brine in the chlor-alkali electrolysis industry.

  2025 04 [Abstract][OnlineView][Download 8743K]
  

Environmental Chemical Engineering

• Decarbonization performance of mixed amine absorbents in sulfur-containingblast furnace gas

  MOU Man¹; XIA Zhixiang¹; XU Xiaoming³; XIA Yang³; XIE Ying¹; HU Ximing²; LIU Zihao³; XIANG Hao³; FANG Mengxiang^1;2

  At present, carbon capture from blast furnace gas is a key focus for low-carbon emission reduction in China’s steel industry. To explore the influence of trace sulfides such as hydrogen sulfide (H₂S) and carbonyl sulfide (COS) in blast furnace gas on the performance of mixed amine absorbents in absorbing carbon dioxide (CO₂) and their reaction characteristics during the chemical absorption decarbonization process, four mixed amine absorbents were formed by using methyl diethanolamine (MDEA) as the main agent and adding piperazine (PZ), aminoethylpiperazine (AEP), 2-(methylamino)ethanol (MMEA) and 2-(ethylamino)ethanol (EMEA), respectively. Additionally, ethanolamine solution (30% MEA, mass fraction) and 40% MDEA solution were used as control groups. The removal rates of H₂S and COS, the absorption rate, regeneration rate and cycle capacity of CO₂ in the mixed amine absorbents under the atmosphere of sulfur-containing blast furnace gas were tested. The results showed that the absorption rate, regeneration rate and cycle capacity of CO₂ in the MDEA + PZ and MDEA + AEP systems were higher than those in the MDEA + MMEA and MDEA + EMEA systems. Piperazine and its derivatives had a better activation effect on tertiary amines than secondary amines. Among them, the CO₂ cycle capacity of the 20% MDEA + 20% PZ absorbent formulation reached 1.87 mol·L^-1, which was 86.2% higher than that of 30% MEA. The removal rate of H₂S was higher than 90%, and it exhibited high CO₂ absorption and regeneration effects and good desulfurization capacity, making it an excellent formula for desulfurization and decarbonization of blast furnace gas. The study also found that trace H₂S and COS had a small impact on the CO₂ absorption and regeneration performances and did not significantly affect the CO₂ absorption rate and cycle capacity. The research provides a theoretical reference for the application of chemical absorption carbon capture in the actual engineering of blast furnace gas decarbonization.

  2025 04 [Abstract][OnlineView][Download 2365K]
  

Environmental Chemical Engineering

• Physical and chemical properties of soot from slurry-bed hydrogenationtail oil gasification

  WANG Yifei; HUANG Xuanxuan; TANG Dongping; WANG Chen; YU Guangsuo; WANG Fuchen

  In order to study the physical and chemical properties of soot in slurry-bed hydrogenation tail oil gasification, using elemental analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and X-ray fluorescence spectroscopy (XRF) were used to systematically characterize and analyze soot from suspension bed hydrogenation tail oil gasification. The results show that the content of fixed carbon, volatile matter, and ash in soot are 43.73%, 19.63%, and 36.64%, respectively; The C/H ratio is 3.93, which belongs to immature soot; The surface of soot exhibits collapse, roughness, and random distribution of irregular small pores. In addition, most soot has a more "hollow" structures; Soot ash exists in the form of aggregates, with the main components V₂O₅, MoO₃, and NiO accounting for 53.33%, 27.13%, and 12.83%, respectively. Therefore, soot can be regarded as a target for vanadium, nickel, and nickel resource recovery; The surface of soot adsorbs soluble organic matter and contains a certain amount of functional groups such as C-O and—OH; The specific surface area and pore volume of soot are only 42.05 m²·g^-1 and 0.13 cm³·g^-1, respectively; Soot shows low combustion reactivity (<i>S</i>=6.9×10^-12 min^-2·℃^-3), which may be due to its internal structural characteristics, which hinders the diffusion and adsorption of oxygen molecules on its surface, thus affecting the speed and efficiency of combustion reaction.

  2025 04 [Abstract][OnlineView][Download 6897K]
  

Environmental Chemical Engineering

• Mechanism and principles of the degradation of C.I.Acid Orange G azo dye via copper(II) ion-activated sodium percarbonate

  WANG Xudong; TANG Yuchao; WU Changnian; ZHU Xiansheng

  In response to the intractable degradation issue of azo dye acid orange G (C.I.Acid Orange G) wastewater, trace amounts of Cu²⁺ were employed to activate sodium percarbonate (SPC) for the degradation treatment of C.I.Acid Orange G, and the reaction mechanism and degradation principle during the degradation process were analyzed. The findings demonstrate that at an C.I.Acid Orange G concentration of 30 mg·L^-1 , with Cu²⁺ and SPC dosages of 5 μmol·L^-1 and 0.2mmol·L^-1 respectively, a 10minutes reaction achieves a removal rate of 91.06%, which increases to 98.39% after 16minutes. An alkaline environment is found to facilitate the degradation process, when pH=9.23, the degradation rate of 16minutes is 99.48%, which is 91.76% higher than that at pH=3.19. HCO^-₃ exhibits significant inhibitory effects on the system, while Cl^-, SO^2-₄, and NO^-₃ show no discernible promoting or inhibiting effects. Radical trapping experiments reveal the presence of singlet oxygen (¹O₂) and carbonate radicals (CO^-₃·) as reactive oxygen species (ROS) within the system. Total organic carbon (TOC) analysis indicates that the system possessesmineralization capabilities, achieving a TOC removal rate of up to 46.2% after 16minutes. Based on the results of ultraviolet-visible absorption spectroscopy and mass spectrometry, the degradation mechanism of C.I.Acid Orange G is as follows: cleavage of the azo bond, ring-opening of the benzene ring, and oxidation of the naphthalene ring. In conclusion, it is established that the Cu²⁺/SPC system effectively degrades C.I.Acid Orange G.

  2025 04 [Abstract][OnlineView][Download 8911K]
  

Environmental Chemical Engineering

• Pyrolysis characteristics of sheets sludge with nitrogen-rich volatiles and the kinetics of high heating rate reactions

  LI Aishu; HAN Hengda; DU Liping; HU Song; XU Kai; XU Jun; JIANG Long; WANG Yi; SU Sheng; XIANG Jun

  The upgrading process of functional biomass residues is accompanied by the generation of a large amount of harmful sheets sludge, posing potential hazards to the environment and human health. Pyrolysis is a critical method for the harmless treatment and resource recovery of sheets sludge. However, sheets sludge exhibits different pyrolysis characteristics compared to municipal sludge due to its smaller molecular weight and higher content of nitro and amino structures in the volatiles. At a heating rate of 100-500℃·min^-1, the pyrolysis reaction kinetics model of sheets sludge transitions from a third-order reaction (F3) to a three-dimensional diffusion reaction (D3), indicating that at high heating rates, the pyrolysis process is limited by heat and mass transfer. Sheets sludge exhibits higher volatile content, with a syngas yield of 205.60mL·g^-1 at 650℃, significantly higher than that of municipal sludge, wherein H₂ and CO proportions exceed municipal sludge by 28% and 25%, respectively, indicating higher syngas quality. At 350℃, sheets sludge tar contained around 20% nitrogen-containing aromatics, four times higher than reported in municipal sludge. As the temperature increased, nitrile, amine, and amide molecules decreased in tar, while pyridine, pyrrole, and indole became the main nitrogen-containing aromatics, accounting for 79.20%~95.83%. In conclusion, the syngas from sheets sludge pyrolysis demonstrate higher quality, and the tar holds the potential to become a nitrogen-rich chemical material.

  2025 04 [Abstract][OnlineView][Download 2276K]
  

Environmental Chemical Engineering

• Removing PFASs in drinking water by calcium chloride-modified nanofiltration membranes

  CHU Tianran^1;2; HOU Dawei³

  With the progression of industrialization, an increasing number of emerging contaminants (ECs) have entered natural water bodies. Among these, per- and poly-fluoroalkyl substances (PFASs) are a particular class of synthetic compounds characterized by their exceptional stability, bioaccumulation potential, and toxicity, posing significant threats to human and ecological health. This study introduced calcium chloride (CaCl₂) into the aqueous phase to facilitate the chelation between Ca²⁺ and acyl chloride monomers, thereby internally regulating the interfacial polymerization (IP) reaction. As a result, a CaCl₂-modified nanofiltration membrane (CaCl₂-TFC) was successfully prepared, featuring a thinner, rougher, more hydrophilic surface with enhanced negative charge and a lower molecular weight cut-off. The impact of CaCl₂ concentration on the separation performance of the nanofiltration membrane was investigated. The results indicate that the modified membrane achieves a pure water flux of 101.86 L·m^-2·h^-1, nearly 3.28 times that of unmodified TFC membrane, with a Na₂SO₄ rejection rate of 95.61%, overcoming the trade-off effect of TFC membranes. This alleviates the trade-off effect between water permeability and solute rejection to some extent. Furthermore, the membrane exhibites rejection rates of 95.78% and 90.92% for PFHxA and PFHxS, respectively. This research presents a simple, environmentally friendly, and low-cost method for the fabrication of TFC NF membranes, applying it to the treatment of PFASs and providing a technical reference for ensuring drinking water safety.

  2025 04 [Abstract][OnlineView][Download 14584K]
  
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