Discontinuing application of pre-filter chlorine is a common water treatment plant practice to permit a bioactive filtration process for the removal of soluble Mn. However, soluble Mn desorption has sometimes been observed following cessation of chlorine addition, where filter effluent Mn concentration exceeds the influent Mn concentration. In this paper it is hypothesized that Mn-reducing bacteria present in a biofilm on the filter media may be a factor in this Mn-release phenomenon. The primary objective of this research was to assess the role of Mn-reducing microorganisms in the release of soluble Mn from MnO-coated filter media following interruption of pre-filtration chlorination. Bench-scale filter column studies were inoculated with MR-1 to investigate the impacts of a known Mn-reducing bacterium on release of soluble Mn from MnO coatings. vial assays were developed to gain insight into the impacts of MnO age on bioavailability to Mn-reducing microorganisms and a quantitative polymerase chain reaction (qPCR) method was developed to quantify gene copies of the gene, which is involved in Mn-reduction. Results demonstrated that microbially-mediated Mn release was possible above a threshold equivalent of 2 × 10 MR-1 CFU per gram of MnO coated media and that those organisms contributed to Mn desorption and release. Further, detectable gene copies were associated with observed Mn desorption. Lastly, MnO age appeared to play a role in Mn reduction and subsequent release, where MnO solids of greater age indicated lower bioavailability. These findings can help inform means of preventing soluble Mn release from drinking water treatment plant filters.
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http://dx.doi.org/10.1016/j.wroa.2018.100009 | DOI Listing |
ACS Nano
January 2025
Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu 610041, P. R. China.
The stimulator of interferon genes (STING) pathway exhibits great potential in remodeling the immunosuppressive tumor microenvironment and initiating antitumor immunity. However, how to effectively activate STING and avoid undesired toxicity after systemic administration remains challenging. Herein, platinum(IV)-backboned polymer prodrug-coated manganese oxide nanoparticles (DHP/MnONP) with pH/redox dual responsive properties are developed to precisely release cisplatin and Mn in the tumor microenvironment and synergistically amplify STING activation.
View Article and Find Full Text PDFMolecules
December 2024
Shanxi Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China.
Lithium-sulfur (Li-S) batteries have emerged as a promising candidate for next-generation high-energy rechargeable lithium batteries, but their practical application is impeded by the sluggish redox kinetics and low sulfur loading. Here, we report the in situ growth of δ-MnO nanosheets onto hierarchical porous carbon microspheres (HPCs) to form an HPCs/S@MnO composite for advanced lithium-sulfur batteries. The delicately designed hybrid architecture can effectively confine LiPSs and obtain high sulfur loading up to 10 mg cm, in which the inner carbon microspheres with a large pore volume and large specific surface area can encapsulate high sulfur content, and the outer MnO nanosheets, as a catalytic layer, can improve the conversion reaction of LiPSs and suppress the shuttle effect.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Environmental Engineering, Kwangwoon University, Seoul, 01897, Republic of Korea.
This study explores the enhanced adsorption performance of activated carbon felt (ACF) for Cu(II) and Cd(II) ions, achieved using a dual-synergistic approach combining MnO coating and plasma treatment. ACF's intrinsic properties, including a high surface area (~ 1000-2000 m²/g), large porosity, and excellent mechanical stability, make it a promising material for environmental applications. However, its limited surface functional groups hinder its adsorption efficiency for heavy metals.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
School of Physics and Electronic Sciences, Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, Changsha University of Science and Technology, Changsha 410114, PR China. Electronic address:
Developing a catalytic nanoenzyme activated by the tumor microenvironment (TME) shows excellent potential for in situ cancer treatment. However, the rational design of a cascade procedure to achieve high therapeutic efficiency remains challenging. In this study, the colorectal TME-responsive multifunctional cascade nanoenzyme CuO@MnO@glucose oxidase (GOx)@hyaluronic acid (HA) was developed to target in situ cancer starvation/chemodynamic therapy (CDT)/photothermal therapy (PTT).
View Article and Find Full Text PDFSmall
January 2025
State Key Laboratory of Electromechanical Integrated Manufacturing of High-performance Electronic Equipment, School of Mechano-Electronic Engineering, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710071, China.
In this research, a novel detection method employing rare-earth upconversion nanoparticle (UCNP) as the core, coated with MnO nanosheets is designed, which formed a color and fluorescence dual-responsive UCNP composite material, MnO-modified NaYF:Yb,Tm@NaYF. By enabling both colorimetric and fluorescence methods simultaneously, this composite material allows for the detection of glucose concentration under different conditions, while exhibiting strong resistance to environmental interference, chemical stability, and accuracy. To further enhance the sensitivity of the detection method, a photonic crystals (PCs)-PDMS array where polymethyl methacrylate PCs are deposited onto a substrate composed of PDMS-glass slice with hydrophobic surfaces is developed.
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