Rocking disposable bioreactors are a newer approach to smaller-scale cell growth that use a cyclic rocking motion to induce mixing and oxygen transfer from the headspace gas into the liquid. Compared with traditional stirred-tank and pneumatic bioreactors, rocking bioreactors operate in a very different physical mode and in this study the oxygen transfer pathways are reassessed to develop a fundamental mass transfer (k a) model that is compared with experimental data. The model combines two mechanisms, namely surface aeration and oxygenation via a breaking wave with air entrainment, borrowing concepts from ocean wave models. Experimental data for across the range of possible operating conditions (rocking speed, angle, and liquid volume) confirms the validity of the modeling approach, with most predictions falling within ±20% of the experimental values. At low speeds (up to 20 rpm) the surface aeration mechanism is shown to be dominant with a of around 3.5 hr , while at high speeds (40 rpm) and angles the breaking wave mechanism contributes up to 91% of the overall (65 hr ). This model provides an improved fundamental basis for understanding gas-liquid mass transfer for the operation, scale-up, and potential design improvements for rocking bioreactors.
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http://dx.doi.org/10.1002/bit.27000 | DOI Listing |
Environ Sci Pollut Res Int
January 2025
Department of Chemical Engineering, Zakir Hussain College of Engineering and Technology, Aligarh Muslim University, Aligarh, 202002, Uttar Pradesh, India.
Water pollution because of the presence of heavy metals remains a serious worry. The present work demonstrates the exclusion of cobalt ion (or Co(II)) from water using novel and cost-effective biosorbents. Initially, the biosorbent was chemically modified using orthophosphoric acid and then subjected to calcination to result acid modified date seed biochar (AMDB).
View Article and Find Full Text PDFSci Rep
January 2025
Department of Environmental Analytical Chemistry, Helmholtz Centre for Environmental Research (UFZ), 04318, Leipzig, Germany.
Nanoplastics are suspected to pollute every environment on Earth, including very remote areas reached via atmospheric transport. We approached the challenge of measuring environmental nanoplastics by combining high-sensitivity TD-PTR-MS (thermal desorption-proton transfer reaction-mass spectrometry) with trained mountaineers sampling high-altitude glaciers ("citizen science"). Particles < 1 μm were analysed for common polymers (polyethylene, polyethylene terephthalate, polypropylene, polyvinyl chloride, polystyrene and tire wear particles), revealing nanoplastic concentrations ranging 2-80 ng mL at five of 14 sites.
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January 2025
Behavioural Ecology Group, Institute of Biology, Leipzig University, Talstraße 33, 04103, Leipzig, Germany.
Primates are well-known for their complex social lives and intricate social relationships, which requires them to obtain and update social knowledge about conspecifics. The sense of smell may provide access to social information that is unavailable in other sensory domains or enhance the precision and reliability of other sensory cues. However, the cognition of social information in catarrhine primates has been studied primarily in the visual and auditory domain.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Sun Yat-Sen University, School of Chemistry, 135 Xingang West, 510275, Guangzhou, CHINA.
Integrating enzymes with reticular frameworks offers promising avenues for access to functionally tailorable biocatalysis. This Minireview explores recent advances in enzyme-reticular frameworks hybrid biocomposites, focusing on the utilization of porous reticular frameworks, including metal-organic frameworks, covalent-organic frameworks, and hydrogen-bonded organic frameworks, to regulate the reactivity of an enzyme encapsulated inside mainly by pore infiltration and in situ encapsulation strategies. We highlight how pore engineering and host-guest interfacial interactions within reticular frameworks create tailored microenvironments that substantially impact the mass transfer and enzyme's conformation, leading to biocatalytic rate enhancement, or imparting enzyme with non-native biocatalytic functions including substrate-selectivity and new activity.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
MOE Key Laboratory for UV Light-Emitting Materials and Technology, Department of Physics, Northeast Normal University, Changchun, Jilin 130024, PR China; Faculty of Chemistry, Northeast Normal University, Changchun, Jilin 130024, PR China. Electronic address:
Considering factors such as crustal reserves, atomic mass, redox potential and energy density, sodium-ion batteries (SIBs) are regarded as the most promising alternative to lithium-ion batteries (LIBs). Transition metal-based layered oxides, especially typical NaMnO, stand out among cathode materials due to their low cost and high energy density. However, NaMnO cathodes face several challenges, including Jahn-Teller distortion, manganese dissolution, structural collapse, irreversible phase transition and significant capacity loss.
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