Three types of wrappped nanoscale zero-valent iron (W-nZVI) with different coatings including agar, starch, and carboxyl methyl cellulose, were synthesized using a rheological phase reaction method. The structure and morphology of W-nZVI particles were characterized by scanning electron microscopy and transmission electron microscopy. Batch degradation experiments exhibited that W-nZVI dosage, initial trichloroethylene (TCE) concentration and solution pH had significant effects on TCE dechlorination. Experimental results proved that the highest dechlorination efficiency was obtained within 320 minutes for 10 mg/L of TCE at the optimal pH of 5.0 and W-nZVI dosage of 0.5 g/L. Kinetic study revealed that TCE dechlorination by W-nZVI in aqueous solution obeyed the quasi-first-order reaction kinetics. The product after the reaction could be easily separated by the permanent magnet for re-use.
- IWA Publishing
- Preparation of wrapped nZVI particles and their application for ...
N. Railroad Ave. Plume Superfund Site - New Mexico
The NRAP site is a state-lead site in its 7th year of groundwater treatment operations by in-situ enhanced reductive dechlorination. The site’s lead agency, the New Mexico Environment Department (NMED), recently completed a response action report to document ongoing progress in their remediation efforts. NMED utilized EnviroInsite in that effort to assist in the interpretation of sampling results.
Treatment of a mixed wood preservative leachate by a hybrid constructed wetland and a willow ...
The performance and removal mechanisms of a hybrid constructed wetland (HCW) followed by a willow planted filter (WPF) were evaluated for the treatment of a leachate contaminated by wood pole preservatives (pentachlorophenol (PCP) and chromated copper arsenate) to reach the storm sewer discharge limits. The HCW aimed to dechlorinate the PCP and polychlorodibenzo-p-dioxins/polychlorodibenzofuran (PCDD/F) and to remove metals by adsorption and precipitation. The HCW was efficient in removing PCP (>98.6%), oil,...
How to deal with hazardous waste?
At present,hazardous waste is a facing an increasingly serious environmental problem .so the mainstream of industrial waste disposal methods: curing landfill, biochemical method, incineration disposal method. Other hazardous waste disposal methods include high temperature steam sterilization, microwave, plasma incineration, pyrolysis incineration, wet air oxidation, advanced biology, alkali metal dechlorination, cement kiln incineration, melt incineration, centrifugal separation and electrolytic oxidation.
Chlorate adsorption from chlor-alkali plant brine stream
Chlorates are present in the brine stream purged from chlor-alkali plants. Tests were conducted using activated carbon from coconut shell, coal or palm kernel shell to adsorb chlorate. The results show varying levels of adsorption with reduction ranging between 1.3 g/L and 1.8 g/L. This was higher than the chlorate generation rate of that plant, recorded at 1.22 g/L, indicating that chlorate can be adequately removed by adsorption using activated carbon. Coconut based activated carbon exhibited the best adsorption...
Degradation of 4-chlorophenol by mixed Fe0/Fe3O4 nanoparticles: from the perspective of mechanisms
Fe0 nanoparticles have been widely studied for pollution abatement in recent years; however, regarding the mechanism for pollutant degradation, studies have mainly focused on the reductive dechlorination by Fe0, and the dynamic process has not been clarified completely. As reported, some organics could be degraded during the oxidation of Fe0 by O2, and hydrogen peroxide was supposed to be produced. In this study, Fe3O4, an oxidation product of Fe0, was used to treat the pollutant combining with Fe0 nanoparticles,...