The oxidation of atrazine (ATZ) was studied in the presence of hydrogen peroxide (H(2)O(2)) and ferrihydrite at different concentrations and pHs. The rate of ATZ oxidation increased with H(2)O(2) concentration and is independent of pH ranging from 4 to 8. However, at pH 3 an increase of ten times in the rate of ATZ oxidation was observed due to the mineral dissolution. The decomposition rate of H(2)O(2) was three times higher at pH 8 than 3 and increased with increase of both H(2)O(2) and ferrihydrite concentrations. The results indicate that ferrihydrite controls oxidation of ATZ by H(2)O(2) in two different ways: (i) mineral dissolution at low pH allowing the Fenton reaction to proceed in solution and (ii) surface-mediated decomposition of H(2)O(2) producing non-reactive oxygen species in particular at higher pH. Three degradation products (desethylatrazine, desisopropylatrazine, and 2-hydroxyatrazine) were identified and corroborate with a Fenton reaction taking place in solution.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.watres.2006.09.016 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Coexisting ferrihydrite-enhanced contaminant degradation during pyrite oxygenation.
J Hazard Mater
December 2024
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, PR China; Key Laboratory of Urban Water Supply, Water Saving and Water Environment Governance in the Yangtze River Delta of Ministry of Water Resources, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China. Electronic address:
Oxygenation of pyrite (Py) is known to mediate generation of reactive oxygen species (ROS) with these species capable of inducing contaminants degradation, whereas the possible participation of coexisting Fe(III) minerals in these processes is still unclear. This study finds that freshly formed ferrihydrite (Fh) significantly enhances the Py-mediated sulfamethoxazole (SMX) degradation process. Through the Fe isotope tracer experiment and a series of control experiments, Fh is found to be reduced by Py to form secondary solid-phase Fe(II) species (Fe(II)) which in turn facilitates generation of HO from the O reduction pathway.
View Article and Find Full Text PDFReactions between ferric oxyhydroxide mineral coatings and a dimethoxyhydroquinone: A source of hydroxyl radicals.
Sci Total Environ
November 2024
Centre for Environmental and Climate Science, Lund University, SE-223 62 Lund, Sweden.
Quinones are organic molecules that facilitate electron-transfer reactions in terrestrial environments. The reduced forms, hydroquinones, are powerful reductants that can trigger non-enzymatic radical-based decomposition of organic matter and contaminants by simultaneous reduction of iron and oxygen. Iron oxides often occur as coatings on other minerals, thus our study investigated the reactions between the ferric oxyhydroxide (FeO(OH)) surface coatings on gibbsite (Al(OH)) and 2,6-dimethoxy-1,4-hydroquinone (2,6-DMHQ).
View Article and Find Full Text PDFCritical roles of low-molecular-weight organic acid in enhancing hydroxyl radical production by ferrous oxidation on γ-AlO mineral surface.
Water Res
September 2024
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu Province, PR China. Electronic address:
Recognizing the pervasive presence of alumina minerals and low-molecular-weight organic acids (LMWOAs) in the environment, this study addressed the gap in the interaction mechanisms within the ternary system involving these two components and Fe(II). Specifically, the impacts of LMWOAs on hydroxyl radicals (•OH) production and iron species transformation during Fe(II) oxidation on γ-AlO mineral surface were examined. Results demonstrated that adding 0.
View Article and Find Full Text PDFInsights into sunlight-driven transformation of tetracycline by iron (hydr)oxides: The dominating role of self-generated hydrogen peroxide.
Water Res
July 2024
MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China. Electronic address:
Iron (hydr)oxides are abundant in surface environment, and actively participate in the transformation of organic pollutants due to their large specific surface areas and redox activity. This work investigated the transformation of tetracycline (TC) in the presence of three common iron (hydr)oxides, hematite (Hem), goethite (Goe), and ferrihydrite (Fh), under simulated sunlight irradiation. These iron (hydr)oxides exhibited photoactivity and facilitated the transformation of TC with the initial phototransformation rates decreasing in the order of: Hem > Fh > Goe.
View Article and Find Full Text PDFInsights into the Crystallinity-Dependent Photochemical Productions of Reactive Oxygen Species from Iron Minerals.
Environ Sci Technol
June 2024
Department of Environmental Science, Zhejiang University, Hangzhou 310058, China.
Iron minerals are widespread in earth's surface water and soil. Recent studies have revealed that under sunlight irradiation, iron minerals are photoactive on producing reactive oxygen species (ROS), a group of key species in regulating elemental cycling, microbe inactivation, and pollutant degradation. In nature, iron minerals exhibit varying crystallinity under different hydrogeological conditions.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!