Microporous aeration has been widely used to restore eutrophic water bodies. The gas-liquid mass transfer in the aeration process has a significant influence on the improvement of water quality. Therefore, the influence mechanism of oxygen mass transfer is worth studying. However, the influence of bubble movement characteristics on oxygen mass transfer has not been systematically studied. https://www.selleckchem.com/products/yoda1.html Thus, the present study explored the influence mechanism of microporous apertures on oxygen mass transfer in terms of bubble motion characteristics by investigating the oxygen mass transfer process and the feature of bubble movement under different aeration microporous aperture sizes. The results showed that the mass transfer efficiency was reduced as the micropore aperture increased from 200 to 400 μm. and the reduction rate was 7.17% when the aperture increased from 200 to 300 μm, which was lower than that from 300 to 400 μm (19.17%). Furthermore, the micropore aperture showed a positive correlation with the time-averaged velocity field. With the increase in aperture, the bubble velocity gradient (from the center to both sides of the edge) increased from about 0.2 to 0.4 m/s, which increased the oxygen mass transfer effect. The increase of micropore aperture caused the increase of average Sauter bubble diameter and the decrease of specific surface area of bubbles. In addition, the negative effects of the reduction of specific surface area and the shortening of bubble residence time on oxygen mass transfer efficiency were greater than the positive effects of the increase of turbulent kinetic energy. When the aperture changes from 300 to 400 μm, the shortening of bubble residence time should have played a major role. This study provides some theoretical parameters for investigating the mechanism of oxygen mass transfer in microporous aeration.Due to its environmental friendliness and biodegradable ability, the enzymatic decolorization of azo dyes is the best option. However, the free enzyme suffers from various limitations, including poor stability, no repeatable use, and a high expense, which is the key drawback for its practical use. In this analysis, the laccase enzyme was immobilized in mesoporous silica coated magnetic multiwalled carbon nanotubes (Fe3O4-MWCNTs@SiO2) by a glutaraldehyde cross-linker to create an easily separable and stable enzyme. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) were used to characterize the as-synthesized Fe3O4-MWCNTs@SiO2. Laccase immobilized in Fe3O4-MWCNTs@SiO2 showed a good improvement in temperature, pH, and storage stability. Moreover, the operational stability of the biocatalyst was improved, retaining 87% of its original activity even after 10 cycles of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) oxidation. The biocatalysts were applied for the decolorization of selected azo dyes without a mediator, and up to 99% of Eriochrome Black T (EBT), 98% of Acid Red 88 (AR 88), and 66% of Reactive Black 5 (RB5) were decolorized. Based on these properties, the biocatalysts can be potentially utilized in various environmental and industrial applications.Plant polyphenols have attracted attention in recent years due to their ability to undergo oxidative coupling reactions enabled by the presence of multiple phenolic hydroxyl groups, forming chemically versatile coatings and biocompatible nanoparticles (NPs) for various applications. The aim of this study was to investigate whether coffee bean aqueous extracts, which are known to be rich in polyphenols, could serve as a natural source of NP building blocks. Extracts were prepared by heating ground Arabica beans of varying roasting degrees in water with or without the addition of sodium metaperiodate or copper sulfate as an oxidizing agent, followed by filtration. NP formation was verified by dynamic light scattering and transmission electron microscopy, which revealed the presence of nano-sized particles with varying sizes and polydispersities as a function of the coffee type and oxidizing agent used. NP colors ranged from light to medium to dark brown, and particle sizes were between 44 and 250 nm with relatively low polydispersity indices. In vitro antioxidant assays showed that oxidizing agent-treated coffee NPs had lower antioxidant potency compared to air-oxidized NPs, but the free-radical scavenging activity was still retained. Coffee NPs exhibited no antimicrobial activity against common bacterial and fungal strains. Cell viability assays demonstrated that the NPs were biocompatible in human dermal fibroblasts, while exhibiting antiproliferative activity against MCF7 breast cancer cells, particularly copper sulfate-oxidized NPs. This study presents a facile and economical method to produce template-free antioxidant NPs that may be explored for various applications such as drug delivery and cosmetics.In this work, the gas-solid flow and water vaporization process are simulated by the method of Euler-Eulerian two-fluid model in a three-dimensional spouted bed, which have a significant influence on the desulfurization efficiency. The results of simulation indicate that the change trends of the particle volume fraction are similar under superficial gas velocities of 0.7 and 0.8 m/s. The degree of particle pulsation is the highest at the bottom of the spout area, and the degree of gas pulsation is the highest at the junction of the annulus area and spout area. The temperatures of gas, liquid, and particles are also analyzed. The results demonstrate that in the spout area, the gas temperature is much higher than that of the liquid and particles, but the three phases are uniformly mixed and have similar temperatures in other areas. Moreover, water vaporization mainly occurs at the junction of the annulus area and the spout area, a small amount of liquid is vaporized at the center of the spout area, and basically no vaporization reaction occurs in the outer radius of the annulus area. With the increase in gas velocity, gas temperature, and liquid temperature and the decrease in gas humidity, water vaporization reaction is promoted.