Washing and drying processes are essential when synthesizing nano-scale zero valent irons (nZVIs) by borohydride reduction of iron salts in aqueous phase. However, effects of these processes on nZVI reactivity have not been investigated in detail, although different washing and drying conditions might alter surface characteristics of nZVIs and thus vary their reactivity towards reducible contaminants. In this study, effects of three washing solutions and drying conditions on the reactivity of nZVIs for nitrate were investigated. Washing with volatile solvents and drying under anaerobic condition decreased thickness of Fe-oxide layer on nZVIs and increased content of Fe(2+)-containing oxides in the layer, which enhanced nZVI reactivity toward nitrate. Volatile solvent washing could minimize the decrease in nZVI reactivity according to changing anaerobic drying condition to aerobic. Findings from this study suggest that application of washing with volatile solvents and drying under aerobic condition should be recommended as effective processes to obtain nZVIs with maximum reactivity at reasonable costs and efforts.
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http://dx.doi.org/10.1016/j.chemosphere.2013.11.010 | DOI Listing |
Environ Res
January 2025
Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China. Electronic address:
Residual antibiotics in aquatic environments pose health and ecological risks due to their persistence and resistance to biodegradation. Thus, it is crucial to develop efficient technologies for the degradation of such antibiotics. This study presents a novel approach using a nano zero-valent iron/graphitic carbon nitride (nZVI/g-CN)-enhanced dielectric barrier discharge (DBD) plasma process for the degradation of ciprofloxacin (CIP).
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou, Fujian 350118, China. Electronic address:
The essential shortcoming of rapid passivation deactivation limits the efficient application of nano zero-valent iron (nZVI) in eliminating disinfection byproducts from drinking water. Copper-coated nano zero-valent iron (Cu-nZVI) bimetallic composites were synthesized to efficiently activate persulfate (PS) to remove nitrosopyrrolidine (NPYR). By introducing Cu-coated coatings, nZVI is protected from direct contact with PS; thus, Cu-nZVI appears to activate PS efficiently and stably without rapid deactivation.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Key Laboratory of Jiangxi Province for Functional Biology and Pollution Control in Red Soil Regions, School of Life Science, Jinggangshan University, Ji'an, 343009, China. Electronic address:
Sulfonamide antibiotics (SAs) are widely used in the biomedical field but pose an environmental risk as ecotoxic pollutants. Developing eco-friendly methods to degrade SAs into harmless compounds is crucial. In this work, biochar (BC) was prepared from rice straw via pyrolysis and used to support S-nZVI, thereby forming the S-nZVI/BC composites.
View Article and Find Full Text PDFSci Total Environ
January 2025
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
It is a great challenge to depict the evolution process of soil-nanomaterials micro-interfaces during soil remediation. A novel biochar loaded nano zero-valent iron (BC-nZVI) reactor with low density, high reactivity and suitable magnetism was prepared using the method we established. Fe nanoparticles (NPs) with the size <10 nm uniformly embedded in a layer of porous carbon networks, which attached firmly in the pores and outer surface of biochars.
View Article and Find Full Text PDFPolymers (Basel)
November 2024
Faculty of Architecture, Civil and Transportation Engineering, Beijing University of Technology, Beijing 100124, China.
The study of the co-transport of Cr(VI) and microplastics (MPs) in porous media is important for predicting migration behavior and for achieving pollution removal in natural soils and groundwater. In this work, the effect of MPs on Cr(VI) migration in saturated porous media was investigated at different ionic strengths (ISs) and pHs. The results showed that pH 7 and low IS (5 mM), respectively, promoted the movement of Cr(VI), which was further promoted by the presence of MPs.
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