Adsorption and reduction of some aromatic contaminants with nanoscale zerovalent irons and further treatments
Journal
ACS Symposium Series
Journal Volume
1150
Pages
147-158
ISBN
9780841229167
Date Issued
2013
Author(s)
Abstract
The nanoscale zerovalent iron (NZVI) has been used as a useful tool for the treatment of contaminated sites. NZVI and Pd/Fe nanoparticles were synthesized to investigate the removal of recalcitrant aromatic contaminants such as decabrominated diphenyl ether (DBDE), hexachlorobenzene (HCB), pentachlorophenol (PCP), and Congo red (CR) and some geochemical effects were also evaluated. These recalcitrant aromatic compounds can be fast removed with NZVIs. The degradation with NZVIs is favorable in an acid condition. Increasing the dose of NZVI particles enhanced the dechlorination rates of HCB. With an increase in temperature, the degradation rate increases. The degradation kinetics of HCB was not influenced by the HCO3- ion but was enhanced in the presence of the Cl- ion due to its corrosion promotion. The NO3- competes with the reactants so it inhibits the degradation reaction. The enhancement effect of Cu2+ and Ni2+ ions on the degradation of PCP by Pd/Fe nanoparticles results from the deposition of reduced forms of copper and nickel on Pd/Fe surfaces. The debromination of PBDEs from para positions is more difficult than that from meta or ortho positions. Furthermore, adsorption process plays an important role on the removal mechanism on these halogenated aromatic compounds with NZVIs. The effect of the combination of microorganisms or sequential Fenton treatments on the mineralization of some contaminants was also evaluated. Anaerobic microbes co-incubated with MZVI could lead to the enrichment of heterotrophic microbial populations and increase DBDE removal. Rapid decolorization of CR by NZVI and sequential Fe(II)(produced from NZVI)/H2O2 process can effectively decompose CR. To combine other treatment processes, the application of NZVI can be more attractive in pollutant removal. These better understandings serve as a useful reference for remediation design and prediction of treatment efficiency of aromatic contaminants with NZVIs. © 2013 American Chemical Society.
SDGs
Type
journal article