Fe-catalyzed S(IV) oxidation revisited: Roles of iron ligands and dissolved oxygen.

J Hazard Mater

Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, China; Technology Innovation

Published: September 2025


Category Ranking

98%

Total Visits

921

Avg Visit Duration

2 minutes

Citations

20

Article Abstract

Fe(III)-catalyzed sulfite oxidation is a critical process that influences the sulfur transformation in atmospheric waters and contributes to acid precipitation. Despite being an old topic, it has not yet succeeded to establish a universally accepted reaction model since real-time data on dissolved oxygen (DO) consumption is not incorporated. Utilizing an advanced fibre optic oxygen meter, kinetics of Fe(III)-catalyzed sulfite oxidation were revisited. In contrast to the promoting role of oxalate in traditional photochemical Fe(III)-S(IV) system, the presence of either oxalate or malonate significantly diminished the rates of the sulfite oxidation and the oxygen consumption under dark conditions, by inhibiting inner-sphere complexation of Fe(III) with sulfite, with the kinetic rate ratios (k/k) were 282 for the ferric sulfate system, 0.13 for the Fe(III)-oxalate system and 67 for the Fe(III)-malonate system. This study further elucidated the central role of dissolved oxygen, which acts as the terminal electron acceptor facilitating the redox cycling of Fe(II)/Fe(III), thereby regulating the free radical chain reaction pathway from SOto SO. The present work is significant for advancing the understanding of the redox reactions of the aqueous Fe-S(IV)-DO system and for establishing kinetic models in aquatic oxygenation reactions by filling the missing link of oxygen.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jhazmat.2025.139478DOI Listing

Publication Analysis

Top Keywords

dissolved oxygen
12
sulfite oxidation
12
oxidation revisited
8
feiii-catalyzed sulfite
8
oxygen consumption
8
oxygen
6
system
5
fe-catalyzed siv
4
oxidation
4
siv oxidation
4

Similar Publications

Populations of the acidophilic purple nonsulfur bacterium were identified in two geographically distinct thermal areas in Yellowstone National Park (Wyoming, USA), as confirmed by 16S rRNA gene sequencing and detection of characteristic methoxylated ketocarotenoids. Microcosm-based carbon uptake assays where oxygenic photosynthesis was excluded via addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea yielded a light-driven dissolved inorganic carbon (DIC) assimilation rate (7 ± 2 mg C g C h) comparable to those of highly productive algal mats in acidic hot springs, suggesting that may be performing photoautotrophy at the time of the assay. Rates of acetate assimilation were more than two orders of magnitude lower than DIC assimilation and did not differ between light and dark treatments, indicating photoheterotrophic use of acetate was not occurring, though photoheterotrophic assimilation of other organic compounds cannot be excluded.

View Article and Find Full Text PDF

Diabetic wounds present persistent challenges due to impaired healing, recurrent infection, oxidative stress, and dysregulated glucose metabolism. Bioinspired polymeric microneedle (MN) patches have emerged as multifunctional platforms capable of penetrating the stratum corneum to deliver therapeutics directly into the dermis, enabling glucose regulation, antimicrobial action, reactive oxygen species (ROS) modulation, and proangiogenic stimulation. Recent experimental evidence has demonstrated that the integration of glucose oxidase-loaded porous metal-organic frameworks, photothermal nanomaterials, and antioxidant hydrogels within dissolvable MNs achieves synergistic bactericidal effects, accelerates collagen deposition, and enhances neovascularization in diabetic wound models.

View Article and Find Full Text PDF

Background And Aim: Hospital effluents are a major source of environmental contaminants, harboring pathogenic bacteria, toxic trace metals, and high organic loads. This study aimed to evaluate the bacteriological and physicochemical profiles of wastewater discharged from three coastal hospitals in Oran, Algeria, and to assess the associated public and livestock health risks under the One Health approach.

Materials And Methods: A cross-sectional study was conducted from January 2023 to February 2024, involving monthly sampling at three hospitals and one drainage collector.

View Article and Find Full Text PDF

Dissolved oxygen (DO) dramatically impacts the habitat use of many aquatic animals, particularly for air-breathing animals that rely on 'physical gills' for respiration while submerged. Invertebrates that use bubbles as physical gills directly uptake DO from the water for respiration. However, no vertebrate animals have yet been documented using physical gills.

View Article and Find Full Text PDF

Beyond Hemoglobin: A Review of Hemocyanin and the Biology of Purple Blood.

Zhongguo Ying Yong Sheng Li Xue Za Zhi

September 2025

PSIT-Pranveer Singh Institute of Technology (Pharmacy), Kanpur - Agra - Delhi, NH#2, Bhauti, Kanpur, Uttar Pradesh, India.

Hemocyanin is dissolved freely in hemolymph, the invertebrate blood substitute, in contrast to haemoglobin, which is encased in red blood cells. When oxygenated, this pigment gives mollusc and arthropod blood its characteristic blue or purple hue. This review article delves into the fascinating biology of hemocyanin, the copper-based oxygen-carrying protein responsible for "purple blood" in many invertebrates, contrasting its characteristics with the more familiar iron-based hemoglobin.

View Article and Find Full Text PDF