Catalysts with high catalytic performance are crucial for the catalytic ozonation of organic wastewater. This study synthesized an efficient, stable, and practical Fe-Mn/Al2O3 ozone catalyst for wastewater treatment u...
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Catalysts with high catalytic performance are crucial for the catalytic ozonation of organic wastewater. This study synthesized an efficient, stable, and practical Fe-Mn/Al2O3 ozone catalyst for wastewater treatment using an impregnation calcination method, and applied it in the catalytic ozonation of wastewater. When the concentration of manganese nitrate was 0.15 mol/L, the Mn/Fe ratio was 3:1, the immersion time was 24 h, the calcination temperature was 500 degrees C, and the calcination time was 4 h, the prepared Fe-Mn/Al2O3 had the best catalytic effect on simulated wastewater, with a chemical oxygen demand (COD) removal efficiency of 73.6 %. At the same time, the physicochemical properties of the catalyst were investigated, and the catalytic effect of the catalyst on actual coking wastewater was investigated on a laboratory scale. When the ozone concentration was 20 mg/L, the gas flow rate was 0.5 L/min, the catalyst concentration was 400 g/L, and the pH was 7.02, the actual COD removal efficiency of coking wastewater was 71.6 %. The pilot test results showed that the COD of the treated coking wastewater could stably meet the standard (COD<80 mg/L), with an average COD removal rate of about 58.3 %, indicating that the Fe-Mn/Al2O3 had high catalytic activity and good stability. Kinetic analysis showed that the degradation process of organic pollutants followed the pseudo-second-order kinetic equation. The results of water quality analysis such as conventional water quality indicators, fluorescence spectroscopy, and molecular weight classification indicated that the large molecular organic pollutants were efficiently degraded. Mechanism analysis indicated that the active components of the catalyst reacted with ozone through electron transfer to enhance the ozone utilization efficiency and efficiently remove organic pollutants. This study can provide theoretical support and technical reference for the standardized discharge of coking wastewater in the future.
The resource utilization of red mud (RM) is crucial for the aluminum industry and for addressing environmental concerns. In this study, RM-based slag pellets were prepared through a cold pressing process and used for ...
The resource utilization of red mud (RM) is crucial for the aluminum industry and for addressing environmental concerns. In this study, RM-based slag pellets were prepared through a cold pressing process and used for converter steelmaking. In the pellet preparation experiment, the effects of binder starch and carboxymethyl cellulose sodium (CMC) dosage, moisture content, drying temperature, particle size, and forming pressure on the strength of RM-based pellets were studied. The formation mechanism of RM particles was determined by analyzing the changes in the crystal structure, functional groups, elemental valence state information, and density functional theory calculations. Finally, the environmental benefits of the pellet production process were analyzed. Under the optimal reaction conditions, the compressive strength of RM pellets prepared based on starch and CMC can reach 1162.06 and 1345.6 N/P, which can meet the production needs of the converter. Mechanism analysis shows that organic adhesives adsorb and solidify particles through chemical or hydrogen bonding, resulting in a denser particle structure. RM particles have an excellent slag and phosphorus removal performance. The results of the life cycle assessment clarify the potential contributions of each stage of particle production. The raw materials and transportation distance have significant impacts on the particle production system. The experimental results provide theoretical guidance and a sustainable evaluation for the production of RM slag aggregates.
Electromagnetic killing is characterized by high efficiency and low cost when dealing with the threat of low, slow and small cluster targets. Firstly, For the characteristics of electromagnetic energy to target can be...
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Hepatitis-hydropericardium syndrome, caused by fowl adenovirus serotype 4 (FAdV-4), has resulted in significant economic damage to the poultry industry. To monitor viral exposure and vaccine efficacy, some traditional...
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Hepatitis-hydropericardium syndrome, caused by fowl adenovirus serotype 4 (FAdV-4), has resulted in significant economic damage to the poultry industry. To monitor viral exposure and vaccine efficacy, some traditional antibody-based immunoassays have been developed for detecting anti-FAdV-4 antibodies. However, these assays have some drawbacks including multi-step operations and higher production cost. Recently, nanobodies are regarded as a promising tool for developing immunoassays. In the study, 23 nanobodies against FAdV-4 were screened and expressed with horseradish peroxidase (HRP) in the HEK293T cells. Then, the FAdV-4-Nb28-HRP fusion protein was selected for developing competitive enzyme-linked immunoassays (cELISA) to detect antiFAdV-4 antibodies in the chicken sera. The optimal concentrations and dilutions for the coating antigen, fusion protein and testing sera were determined to be 400 ng/well, 1:80 and 1:20, respectively. After the coated plates were vacuumized and stored, the operation of cELISA to detect clinical chicken sera was only one-step and the full time was 75 min. The cELISA also exhibited high sensitivity, specificity, reproducibility and good agreement with the commercial ELISA kit. When the sequential sera from the challenged chickens were tested, the cELISA showed superior sensitivity compared with the commercial ELISA kit. Moreover, epitope mapping revealed that the nanobody specifically recognized the sites GLN235 ASN236 SER238 of the fiber-1 protein, highly conserved among different FAdV-4 isolates and different from the FAdV-1 and-8. The results indicated that cELISA can specifically detect anti-FAdV-4 antibodies. Collectively, the developed one-step nanobody-based cELISA is an ideal method for epidemiological investigation and vaccine immune evaluation of FAdV-4.
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