This study was aimed at developing an immobilized bioreactor system in which long-term continuous ferrous iron oxidation can be realized with no formation of jarosite, which causes clogging of support pores and reactor lines. For this purpose, a medium with no jarosite formation was developed first by selecting optimal nitrogen and phosphate sources and their concentrations. Then with the developed medium containing ammonium phosphate instead of ammonium sulfate and potassium phosphate, repeated batch and continuous operations of ferrous iron oxidation by Acidothiobacillus ferrooxidans cells immobilized in a depth filter were successfully performed for an extended period of time. For about 510 h of operation including 450 h of continuous operation at dilution rates of 0.1, 0.2, and 0.3 h(-)(1), no formation of jarosite and thus no clogging of the reactor system were observed. The maximum ferrous iron oxidation rate was as high as 2.6 g/(L.h) at a dilution rate of 0.3 h(-)(1).
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Water Res
January 2025
College of Environmental Science and Engineering, Yangzhou University, Yangzhou 225127, PR China; Key Laboratory of Arable Land Quality Monitoring and Evaluation, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou 225127, PR China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225127, Jiangsu, PR China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, PR China. Electronic address:
Endogenous nitrogen (N) release from lake sediments is one of main causes affecting water quality, which can be affected by the presence of iron (Fe) minerals and organic matter, especially low-molecular-weight organic acids (LMWOAs). Although these substances always coexist in sediments, their interaction effect on N fate is not yet clear. In this study, the role and mechanisms of the coexistence of iron mineral (ferrihydrite, Fh) and LMWOAs, i.
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January 2025
Australian Antarctic Program Partnership (AAPP), Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, TAS, 7004, Australia.
Iron plays a pivotal role in regulating ocean primary productivity. Iron is supplied from diverse sources such as the atmosphere and the geosphere, and hence iron biogeochemical research has focused on identifying and quantifying such sources of "new" iron. However, the recycling of this new iron fuels up to 90% of the productivity in vast oceanic regions.
View Article and Find Full Text PDFChemphyschem
January 2025
Southern Methodist University, Chemistry, 3251 Daniel Ave, 75275, Dallas, UNITED STATES.
We analyzed the intrinsic strength of distal and proximal FeN bonds and the stiffness of the axial NFeN bond angle in a series of cytochrome b5 proteins isolated from various species, including bacteria, animals, and humans. Ferric and ferrous oxidation states were considered. As assess- ment tool, we employed local vibrational stretching force constants ka(FeN) and bending force constants ka(NFeN) derived from our local mode theory.
View Article and Find Full Text PDFBiopolymers
March 2025
Department of Chemistry, School of Chemical and Physical Sciences, Lovely Professional University, Phagwara, India.
In this paper, we offer a unique green synthetic approach for producing iron sulfide quantum dots (FeS QD)-chitosan composites using gel chemistry. The technique uses the environmental features of chitosan, a biocompatible and biodegradable polysaccharide, and the excellent electrical properties of FeS QDs. By sustainable chemistry principles, the synthesis process is carried out under gentle settings, using aqueous solutions and avoiding hazardous solvents and strong chemicals.
View Article and Find Full Text PDFNanotoxicology
January 2025
Institute of Biotechnology, College of Natural Sciences, University of Rzeszow, Rzeszow, Poland.
Urotropine, an antibacterial agent to treat urinary tract bacterial infections, can be also considered as a repurposed drug with formaldehyde-mediated anticancer activity. Recently, we have synthesized urotropine surface modified iron oxide nanoparticles (URO@FeO NPs) with improved colloidal stability and limited cytotoxicity against human fibroblasts. In the present study, we have investigated URO@FeO NP-mediated responses in a panel of forty phenotypically different breast cancer cell lines along with three non-cancerous corresponding cell lines.
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