In this study, changes in the reactivity of nanoscale zerovalent iron (NZVI) in five different groundwater (GW) systems under anoxic and oxic conditions were examined over a wide range of aging time (0 - 60 d). p-nitrophenol (p-NP) was used as a redox-sensitive probe, whereas nalidixic acid (NA), a typical antibiotic found in the natural environment, was used as a sorbing compound. Investigation of the p-NP reduction in pure water systems showed that NZVI lost 41% and 98% of its reductive activity under anoxic and oxic conditions after 60 d, while enhancement of its reactivity was observed after short-term aging in GW (1 - 5 d), followed by a further decline. This behavior has been ascribed to the formation of secondary Fe(II)-bearing phases, including magnetite and green rust, resulting from NZVI aging in GW. Adsorption experiments revealed that GW-anoxic-aged NZVI samples exhibited a good affinity toward NA, and a greater NA adsorption (∼27 µmol g ) than that of pristine NZVI (∼2 µmol g ) at alkaline pH values. Surface complexation modeling showed that the enhanced adsorption of NA onto secondary minerals can be attributed to the Fe(II)-NA surface complexation. This considerable change in the reductive ability and the adsorption capacity of NZVI arising from groundwater corrosion calls for greater attention to be paid in assessment studies, where NZVI is injected for long-term remediation in groundwater.
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http://dx.doi.org/10.1016/j.watres.2022.119472 | DOI Listing |
Environ Sci Technol
January 2025
Faculty of Agriculture, Life, and Environmental Sciences, Zhejiang University, Hangzhou 310058, China.
Electron release and transfer are pivotal to the efficiency of multiple biogeochemical and pollutant processes. Despite substantial efforts to develop electron-transfer characterization techniques, visualization of electron transfer remains challenging. This study introduces an innovative strategy for mapping electron-transfer distance using nanoscale zerovalent iron (nZVI) as a case study.
View Article and Find Full Text PDFJ Environ Manage
January 2025
INDUROT and Environmental Biogeochemistry & Raw Materials Group, Campus of Mieres, University of Oviedo, 33600, Mieres, Spain.
Here we describe two innovative approaches for remediating sediments contaminated with organotin compounds (OTCs, mainly TBT) and metal(loid)s. The first involves chemical stabilization through amendments with nanoscale zero-valent iron (nZVI), dunite mining waste, and coal tailings, materials that have not been previously studied for OTC remediation. The second focuses on physical soil washing, using grain-size separation and magnetic separation to isolate the most polluted fractions, thereby reducing the volume of contaminated material destined for landfills.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Division of Environmental Science and Engineering (DESE), Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea; Division of Advanced Nuclear Engineering (DANE), Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea. Electronic address:
A geopolymer waste form has become a suitable approach for the immobilization of the volatile technetium (Tc) due to the low curing temperature (<60 °C). However, the low retention and the high mobility of the anionic technetium (TcO) remain challenging due to the charge repulsion stemming from the negative charges of the geopolymer surface and the anionic TcO. Herein, a geopolymer composite containing sulfidized nanoscale zerovalent iron (S-nZVI) was developed to reductively immobilize ReO (used as a non-radioactive surrogate for TcO).
View Article and Find Full Text PDFJ Environ Manage
January 2025
Korea Biochar Research Center, Division of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Korea.
Pristine or modified nanoscale zero-valent iron (nZVI) synthesized though conventional chemical reduction have been widely recommended for remediating metal(loid)-contaminated water. However, their eco-friendliness is often challenged with the concomitant bio-toxicity and secondary environmental risks. Alternatively, this study utilized waste tea leaves extract and remaining residue as the reducing agent and pyrolytic matrix to innovatively fabricate a green synthesized nZVI impregnated tea residue biochar (G-nZVI/TB).
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Centre for Applied Research, Saveetha School of Engineering, Saveetha institute of Medical and Technical Sciences (SIMATS), Chennai, Tamil Nadu 602105, India.
Recent advances in nanotechnology, particularly those utilizing polymeric nanocomposites, have garnered significant attention for their effectiveness and biocompatibility in cancer diagnosis and treatment. In this study, a chitosan-okra mucilage polymeric nanocomposite doped with nano zero-valent iron (CS-OM-nZVI), synthesized using green chemistry principles, was evaluated for its anti-cancer activity against drug-resistant oral carcinoma cells (KBChR). The nanocomposite was created from chitosan, mucilage derived from okra biomass, and nano zerovalent iron particles synthesized through chemical reduction.
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