A standard transmembrane pressure (TMP) step method has been used in membrane fouling assessment in tube ultrafiltration (UF) membrane system treating oil water (o/w) emulsion operated at constant TMP. Three flux reduction curve with different o/w concentration based on TMP variation were concluded by experiment, then, to describe fouling behavior and identify the occurrence of fouling in the so-called critical flux. Furthermore, sub-critical and super-critical flux experiment with a long time was determined, and zero rate of flux reduction (dF/dt) was never found during the whole trial period, indicating that critical flux in o/w UF process with its strict definition could not be defined in this paper. However, quasi-critical flux exists, under which the pollution rate was very slow. Moreover, a high-efficiency four steps cleaning method: mechanic scraping, pure water wash, pure water reverse wash, and dosing cleaning, was explored. It concluded that critical flux in real o/w UF system determined by TMP-step method can be used to predict long-term critical behavior with useful data on fouling propensity.
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http://dx.doi.org/10.2166/wst.2017.445 | DOI Listing |
mSystems
January 2025
Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Gluconeogenesis, the reciprocal pathway of glycolysis, is an energy-consuming process that generates glycolytic intermediates from non-carbohydrate sources. In this study, we demonstrate that robust and efficient gluconeogenesis in bacteria relies on the allosteric inactivation of pyruvate kinase, the enzyme responsible for the irreversible final step of glycolysis. Using the model bacterium as an example, we discovered that pyruvate kinase activity is inhibited during gluconeogenesis via its extra C-terminal domain (ECTD), which is essential for autoinhibition and metabolic regulation.
View Article and Find Full Text PDFIn the leucine (Leu) biosynthesis pathway, homeostasis is achieved through a feedback regulatory mechanism facilitated by the binding of the end-product Leu at the C-terminal regulatory domain of the first committed enzyme, isopropylmalate synthase (IPMS). In vitro studies have shown that removing the regulatory domain abolishes the feedback regulation on plant IPMS while retaining its catalytic activity. However, the physiological consequences and underlying molecular regulation on Leu flux upon removing the IPMS C-terminal domain remain to be explored in plants.
View Article and Find Full Text PDFSci Total Environ
January 2025
Department of Biology, Ecology and Earth Sciences (DIBEST), University of Calabria, Ponte Bucci street, cube 15B, 87036 Rende, Italy.
The work aims to estimate natural greenhouse gas emissions from soils in the Sibari Coastal Plain (Southern Italy), to understand (i) the contribution in terms of the total amount of CO and CH emitted in non-volcanic areas, (ii) the relationship among emitted gas, land use, organic matter and tectonic structures, and (iii) their potential environmental implications. Data were elaborated with statistical and geostatistical methods to separate the different populations and obtain prediction and probability maps. Methane fluxes had values consistently below the detection limit (0.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha P.O. Box 34110, Qatar.
The development of ultrafiltration (UF) polymeric membranes with high flux and enhanced antifouling properties bridges a critical gap in the polymeric membrane fabrication research field. In the present work, the preparation of novel PES membranes incorporated with carrageenan (CAR), which is a natural polymer derived from edible red seaweed, is reported for the first time. The PES/CAR membranes were prepared by using the nonsolvent-induced phase separation (NIPS) method at 0.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Physics, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Key Laboratory of Low Dimensional Condensed Matter Physics (Department of Education of Fujian Province), Jiujiang Research Institute, Xiamen University, Xiamen, China.
Silicon-based all-solid-state batteries offer high energy density and safety but face significant application challenges due to the requirement of high external pressure. In this study, a LiSi/Si-LiSi double-layered anode is developed for all-solid-state batteries operating free from external pressure. Under the cold-pressed sintering of LiSi alloys, the anode forms a top layer (LiSi layer) with mixed ionic/electronic conduction and a bottom layer (Si-LiSi layer) containing a three-dimensional continuous conductive network.
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