HYDROMETALLURGY
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2022
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IF 4.217
Jie Tang,Guihua Liu,Tiangui Qi,Qiusheng Zhou,Zhihong Peng,Xiaobin Li,Yilin Wang,Leiting Shen,Jiaping Zhao,HongJie Hao
An understanding of the mechanisms of reactive Al and AlN in a sodium aluminate solution contributes to the safe and effective utilization of secondary aluminum dross (SAD). This study demonstrates that the slurry temperature increased exponentially with an increase in the SAD dosage. Synergistic kinetic phenomena in the form of a large dosage and high temperature occurred initially in relatively stable microbubbles and later in the slurry. The leaching efficiencies of pure Al and AlN powders were greater than that of Al and AlN in SAD, respectively. Meanwhile, the leaching rate became higher for Al in SAD but lower for AlN in SAD compared to that of pure Al and AlN powder. The AlN particles in SAD were covered by Al(OH) 3 precipitated from the saturated solution in the bubbles. As a result, the relatively stable microbubbles with a thick border accelerated the reaction of Al and AlN and produced a saturated solution thereby changing the leaching efficiency and leaching rate of AlN in SAD. The embedded Al and AlN grains in the SAD, relatively stable microbubbles, and the SAD particles covered by Al(OH) 3 , synergistically changed the leaching mechanism. These results provide further understanding of the reaction mechanism of rich bubbles and facilitate the optimization of the comprehensive utilization of SAD.
研究领域:
冶金学
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2024
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IF 2.7
Hao Wu,Dengwang Lai,Mengyao Nan,Wuyan Cao,Li Liu,Yuejun Liu,Jun Yang
This paper utilizes the reaction of phytic acid (PA) and urea (UM) in polyvinyl alcohol (PVA) solution to synthesize flame retardant gasses (CO 2 , NH 3 ) for the preparation of PVA composite films containing flame retardant microbubbles. The flame retardancy of PVA composite films was assessed using methods including limiting oxygen index (LOI), vertical burning (UL 94), and cone calorimetry. The results indicated an increase in the LOI of the PVA composite film containing flame retardant microfoam from 20% to 30% compared with the pure PVA film, and that UL 94 reached VTM-0. Furthermore, its peak exothermic rate and total exothermic amount were reduced by 36.25% and 38.92%, respectively, compared with the pure PVA film. The investigation of the flame-retardant mechanism employed thermogravimetric-infrared (TG-IR), scanning electron microscopy (SEM), Raman spectroscopy, and infrared spectroscopy. The results demonstrate that the CO 2 and NH 3 flame retardant microbubbles within the composite film render it less ignitable at the initial stage, and that the internal UM of the composite film continues to decompose, releasing CO 2 and NH 3 upon heating. In addition, the acidic substances decomposed by PA during combustion promote the dehydration, cross-linking, and cyclization of PVA, generating chemical structures such as P O C, P O P, and PO 4 with enhanced thermal stability. This encourages the formation of a continuous, dense charcoal layer and impedes the transfer of oxygen and heat into the interior.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
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2019
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IF 4.087
Yimou Fu,Haotian Lu,Guodong Nian,Peng Wang,Nan Lin,Xiaocheng Hu,Haofei Zhou,Honghui Yu,Shaoxing Qu,Wei Yang
High-rate loading induced cavitation of soft materials, including brain and muscle, has increasingly been studied due to its importance in a variety of biomedical applications , such as potential impact-related traumatic brain injury and high-intensity focused ultrasound therapy. The size of cavitation nuclei or defects is crucial to the onset of cavitation. However, it remains challenging to introduce gaseous defects with controllable size into soft materials and to understand the underlying mechanism of impact-bubble interaction in soft materials. Here, we set up a drop-tower system to perform impact loading tests on gelatin samples with controllable monodispersed microbubbles, allowing us to mimic the general cavitation behavior of human tissues. The microbubbles are inserted into the soft matrix as cavitation nuclei by taking advantage of microfluidic flow focusing. A high-speed camera paired with a signal acquisition system is utilized to determine the critical pressure at which cavitation initiates for different defect sizes . Meanwhile, we propose a theoretical model based on surface tension to predict the time-dependent spherically symmetric cavitation of a pre-existing gas bubble in elastomers under high-speed loading. Our experiments and theoretical modeling demonstrate the strong effect of gas-filled defects on cavitation and indicate the necessity and significance of controlling defect size in mimicking targeted organs using soft gels. Our work provides a promising route to predict cavitation-induced injury in tissues with variable materials stiffness and initial defect size.
研究领域:
生物力学
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医学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
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IF 5.518
Ming Li,Ming Xu,Lijuan Sun,Chunyun Zhu,Jincheng Liu,Qinshan Liu,Yaowen Xing,Xiahui Gui
The surface microbubbles (SMBs) induced by air nucleation on mineral surfaces exert a powerful influence over enhancing the adhesion of air bubbles or oil droplets on mineral surfaces in flotation . The contact angles and TPLs were characterized by captive-bubble/oil droplet on the graphite surfaces. They were combined with dynamic bubble/oil droplet-graphite surface attachment and detachment visualization and force measurements using a microbalance system equipped with a camera to demonstrate the role of SMBs in bubble/oil droplet-graphite surface adhesion. The results show that after depressurization, the dissolved air in water nucleates on both hydrophobic and oxidized graphite surfaces, resulting in SMBs formation, which can enhance the adhesion of bubbles/oil droplets with the different graphite surfaces. For bubble-solid adhesion, these enhancements are attributed to the bridging effect of the SMBs coalescing with the large bubble increasing three-phrase contact lines (TPLs) and with this the adhesion forces. For oil-solid interactions, SMBs induce the attachment and spreading of the oil droplet on the graphite surfaces, as the TPLs and spreading forces are increased. SMBs also result in a more stable oil droplet-graphite interface, as the adhesion forces are improved. Therefore, SMBs are efficient for improving graphite flotation by increasing the stability of the mineralized bubble and promoting the spreading and adhesion of dodecane oil. Hence, SMBs coupled with the modification of the surface hydrophobicity may be more beneficial for flotation separation.
研究领域:
矿物加工工程
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界面科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Water Process Engineering
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2023
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IF 7
Ce Wang,Yuling Lü,Chao Song,Jiakai Shi,Peng Zhang,Limin He
The poor adhesion of oil droplets and bubbles in the flotation process leads to inefficient separation of oil and water. In this paper, condensate bubbles were prepared by partial vaporization of low boiling point condensate to increase the oil removal effect. The purpose of partial vaporization was achieved by bringing emulsified condensate droplets into the produced water at different temperatures. The structure of the bubble is composed of condensate film wrapped around the gas core of the vaporized portion. The contact angle between condensate bubble and oil surface is >150°, which show great similarity-intermiscibility. The average bubble size prepared at 303 K - 318 K is 20 - 100 μm. The stability of bubbles decreased with an increase in temperature, the half-decay time decreased from 340 s to 110 s, and the zeta potential decreased from −31 mV to −12 mV. However, the gas hold-up of the bubbles first increased and then decreased with the increase in temperature, while the highest gas holdup was 21 % at 313 K. The rise of the condensate/water ratio (R con-wat ) did not increase the stability of the bubbles, but the gas holdup increase. The condensate bubble flotation experiment found that at the optimum temperature 313 K, the oil removal efficiency of 1.5 % R con-wat can reach 85 %. In contrast, the oil removal efficiency of the dissolved air flotation experiment is <75 %. Otherwise, with a smaller amount of flocculant (ferric chloride), the oil removal efficiency of condensate bubble flotation can reach >95 %.
研究领域:
石油工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
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2024
·
IF 8.3
Xuelin Wang,Xitong Wang,Chenao Xu,Yubing Ye,Rongsheng Ning,Ratul Rehman,Enchao Li,Pan Li
Fouling control strategies play a crucial role in membrane distillation (MD) process, primarily due to the significant limitation of fouling during the scaling-up process. The utilization of microbubbles (MBs) aeration has exhibited promising potential in mitigating membrane fouling when treating high salinity wastewater. Aeration can introduce gas-liquid two-phase flow on the membrane surface , thereby increasing the membrane surface shear force. The mechanism of aeration technology for controlling fouling includes the following points: introduction of gas-liquid two-phase flow; physical substitution of concentration polarization layer ; pressure pulses caused by bubbles flowing through the membrane surface and increasement of the cross flow velocity. This research aims to optimizing the effect of air MBs with different concentrations and sizes introduced in the feed side on membrane fouling control, we creatively used the method of releasing pressure gradiently to achieve size regulation of MBs within a certain range for the first time, firstly regulated the generation of MBs by manipulating gas flow rate and release pressure. Under the optimal condition of 40 mL/min and 0.6 MPa, it will yield concentration of 1.58 × 10 4 /mL and D50 Sauter size of 64.69 μm MBs with pure water permeance flux of 12.32 kg/(m 2 ·h). It was observed that higher gas flow rates primarily increased MBs concentration, while lower pressures predominantly reduced MBs size through the method of inline imaging. Experimental results indicated that introduction of MBs can slightly improve the temperature polarization coefficient and mass transfer coefficient under different operating modes. Consequently, further investigations focused on the influence of MBs characteristics on different fouling control. All conditions reach 99 % rejection for inorganic salt and HA. This study provided empirical evidence that higher concentration and larger size of MBs intensify the gas-liquid two-phase flow disruption and exhibit a better shear effect on scaling phenomena, which yield advantageous outcomes in terms of augmenting permeance flux and water vapor production, with permeance flux increased from 40.12 % to 55.42 % for inorganic fouling and increased from 68.35 % to 80.15 % for inorganic and HA fouling. These results were confirmed via membrane surface using scanning electron microscopy and energy dispersive spectroscopy. In summary, this research aided in identifying appropriate operating conditions for mitigating inorganic and composite scaling by implementing air-infused MBs in direct contact membrane distillation (DCMD), which provides scientific and technical guidance for controlling fouling in MD in practical applications.
研究领域:
环境工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Water Process Engineering
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2022
·
IF 7.34
Yonglei Wang,Xinglin Wang,Liping Tian,Yanan Li,Guilin He,Haiyang Yu,Hua Qi,Wentao Sun
Algal blooms in lake and reservoir water lead to water quality problems, including water odors, algal toxins, and disinfection byproducts . A novel dissolved air flotation process that incorporates positively charged bubbles (PosiDAF) can effectively remove algae in lakes and reservoirs. Chitosan, as a modified bubble agent in the PosiDAF process, has attracted extensive attention due to its natural nontoxicity and good flocculation properties. In this paper, three types of amphiphilic chitosan with different lengths of carbon chains were prepared via amphiphilic modification and were used as bubble modifiers to remove microcystis aeruginosa in the PosiDAF process. The effects of algae removal under different dosage of modifiers were compared, and the role of algal organic matter was investigated. Results showed that the water solubility of chitosan was markedly enhanced after amphiphilic modification, while thermal stability were decreased. When using butyl-N-2 hydroxypropyl trimethyl chitosan ammonium chloride (C4-HTCC), the effect of modified air flotation was the best, and the removal ratio of algae was 93.47% when the C4-HTCC dosage was 1.0 mg/L. The presence of AOM enhanced the overall effect of algae removal, and electrostatic attraction was the primary adhesion mechanism of the microbubble-amphiphilic chitosan-algal organic matter-algal cell system. In addition, adsorption bridging and net trapping also have positive effects on algae removal.
研究领域:
环境科学
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水处理技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2024
·
IF 8.4
Shinan Xu,Guodong Kang,Bihai Chen,Yunhao Li,Xingming Jie,Yiming Cao,Xiaoyan Fu,Wu Kuang,Ning Cao,Haijun Yu
In this study, an innovative strategy of fabricating Janus hollow fiber membrane to produce microbubbles for enhancing CO 2 removal was proposed. The polyvinylidene difluoride (PVDF) hollow fiber membrane was prepared using two different hydrophilic dopes followed by modification with 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (FAS). The contact angle of the Janus hollow fiber membrane was 37° for the outer layer and 122° for the inner layer. Attenuated total reflectance Fourier transform infrared spectrometer (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) were employed to verify the grafting of FAS onto the inner layer of membrane. The unique morphology showing a progressive transition from sponge-like to finger-like pores, extending from the inner to the outer layer, was examined using a scanning electron microscope (SEM); this morphology helped reduce mass transfer resistance. Microbubbles were produced by the prepared Janus hollow fiber membrane at high and consistent fluxes. The CO 2 mass transfer flux reached 5.0 × 10⁻³mol m⁻ 2 s⁻ 1 under the gas-liquid pressure difference of 0.10 MPa. The average size of microbubbles was 75 μm and the CO 2 removal rate was nearly 100 % in CO 2 removal experiments. The Janus hollow fiber membrane developed in this study exhibited good aeration property and application potential in post-combustion CO 2 capture.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Qinyu Han,Tao Lin,Jiayu Du,Wei Liu
In order to remove the trace organic contaminants (TrOCs) in drinking water, an advanced oxidation system using ceramic membrane aeration was proposed in this study to generate ozone microbubbles (CA/O 3 ). The pesticide atrazine (ATZ) was selected as the target pollutant. The results showed that a 35.51 % higher removal efficiency was achieved using CA/O 3 compared to the traditional titanium diffuser aeration (TA/O 3 ). This improved performance was attributed to the higher aeration pressure in CA/O 3 , which resulted in a greater actual ozone dosage under identical inlet gaseous ozone flow rate and concentration. The microbubbles with small size, large specific surface area and prolonged residence time, further enhanced the aqueous ozone concentration and mass transfer rate within CA/O 3 . ·OH was found to be the main active species for ATZ degradation. Electron paramagnetic resonance (EPR) spectroscopy and probe experiments confirmed that the exposure ratio of ·OH in CA/O 3 was 2.12 times higher than in TA/O 3 . This contributed to the effective degradation of ATZ. Inlet gaseous ozone concentration was the critical factor influencing ozone mass transfer and degradation efficiency. Through LC-MS/MS analysis, coupled with frontier molecular orbital calculations, ten ATZ transformation products were identified, and dechlorination-hydroxylation and dealkylation were verified to be the primary transformation pathways. Based on blood flow activity, moving distance, and heart rate in zebrafish, toxicity assessments indicated that CA/O 3 effectively mitigated the toxicity of the transformation products. Therefore, CA/O 3 can be to efficiently degrade ATZ, ensuring effective control of toxicity associated with degradation products.
研究领域:
环境科学
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化学工程
·
毒理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ULTRASOUND IN MEDICINE
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2024
·
IF 2.1
Xinyu Zhong,Xinghao Zhang,Yuting Cao,Ping Zhou
Objectives This study aimed to explore the interactions between microbubbles and microwave ablation (MWA). Methods The study employed custom-made phantoms (in vitro) and white New Zealand rabbits (in vivo). MWA was performed with or without microbubbles in the phantoms (2 × 10 5 particles mL −1 ) and rabbit livers (intravenous injection of 0.05 mL/kg SonoVue). During the MWA, K-type thermocouple probes were used to monitor the MWA-induced temperature increase. Contrast-enhanced ultrasound imaging (CEUS) was used to monitor and analyze the microbubbles signal intensity. After MWA, the ablation-zone volumes were evaluated and compared between the groups with and without microbubbles. Results In both the phantom models and rabbits, microbubbles showed no significant influence on MWA, including the ablation range and MWA-induced temperature increase. In phantoms and rabbit livers filled with microbubbles, MWA caused the formation of a gradually expanding microbubble-defect region over the ablation time. An increase in the temperature caused microbubble destruction. Conclusions Microbubbles had no significant influence on MWA. However, MWA induced the destruction of microbubbles in a temperature-dependent manner. Thus, the poor thermotolerance of microbubbles is a non-negligible barrier when using CEUS to monitor the ablation range during MWA in real-time.
研究领域:
医学影像学
·
肿瘤学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Water Process Engineering
·
2022
·
IF 7.34
Xiaohong Wang,Yonglei Wang,Liping Tian,Ling Ju,Ruibao Jia,Wuchang Song,Haiyang Yu,Jingjing Li
The eutrophication of reservoir water leads to the proliferation of algae, the DAF process can overcome the lack of algae removal capacity in conventional treatment processes, and its pollution removal efficiency is affected by the equipment performance. Among DAF equipment, multiphase flow pumps have attracted attention because of their simple configuration and low failure rate. This paper studied the equipment performance and pollution removal efficiency of a multiphase flow pump for DAF. The results showed that the dissolution efficiency of the equipment was approximately 55% and the average particle size of bubbles was less than 26 μm. When the pressure was greater than 0.36 MPa, the bubble stability time exceeded 4 min. The optimal working conditions were achieved at a dissolved gas pressure of 0.4 MPa. The maximum removal rates of turbidity , chlorophyll a , TOC, UV 254 and COD Mn by the DAF process were 56.49%, 50.23%, 23.73%, 28.75% and 23.98%, respectively. The trend in pollution removal efficiency was consistent with that of equipment performance parameters. The surface of the microbubbles was hydrophobic and could more easily adsorb high-molecular-weight organic substances with strong hydrophobicity and algae with strongly hydrophobic colloidal layers inside. In addition, regarding the THMFP, the experimental results showed that the removal rates of the precursors CHCl 3 , CHBrCl 2 and CHBr 2 Cl after DAF were 28.93%, 23.26% and 21.53%, respectively. Surface hydrophobicity is one of the main mechanisms by which microbubbles adhere to pollutants.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Xiemin Liu,Jin Jin,Yu Gao,Zheng Zhou,Feng Zhang,Jiao Geng
Efforts have been made to enhance ozone utilization efficiency and reduce energy costs in ozone-aerated wastewater treatment. Microbubbles, characterized by their large interfacial area and efficient gas-liquid mass transfer, are extensively used to boost ozone utilization. However, generating microbubbles demands significant energy, and their actual efficiency requires careful evaluation due to the absence of universal strategies for designing microbubbles with optimal performance. This study established an integrated mathematical model for ozone oxidation in wastewater treatment, based on comprehensive ozone reaction kinetics, microbubble mass transfer control theory, and mass conservation equations for gas-liquid phase components. Simulation results showed a pollutant removal rate with a prediction error of less than 20 %, confirming the model's reliability. Further analysis revealed that although the initial mass transfer rate of 0.5 mm bubbles is lower than that of 0.1 mm bubbles, the total mass transfer quantity is reduced by only 8.7 %. This suggests that an optimal bubble diameter can balance mass transfer efficiency and energy consumption. Based on this finding, we integrated ozone production and bubble generation energy consumption to develop a regulation mechanism for optimizing bubble diameter, minimizing total energy consumption while meeting target removal rates. Results indicate that the optimal bubble diameter is closely related to water depth: as depth increases, the optimal bubble diameter also increases. At a depth of 2.1 meters, the optimized bubble diameter reduces energy consumption by 33.5 % and 16.2 % compared to millimeter-sized and 100-micron bubbles, respectively. Sensitivity analysis shows that total energy consumption is more sensitive to changes in specific ozone energy consumption, while variations in bubble generation energy remain relatively stable. These results underscore the feasibility of using the proposed model to guide energy-efficient bubble size selection.
研究领域:
环境科学
·
废水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）