Interaction of zero-valent iron and carbonaceous materials for reduction of DDT
| Autor: | Sarah Sühnholz, Katrin Mackenzie, Frank-Dieter Kopinke, Anett Georgi |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Environmental Engineering
Hydrogen Halogenation Health Toxicology and Mutagenesis Iron 0208 environmental biotechnology Inorganic chemistry chemistry.chemical_element 02 engineering and technology 010501 environmental sciences Electrochemistry 01 natural sciences Chemical reaction Catalysis DDT chemistry.chemical_compound Hydrolysis Adsorption Environmental Chemistry Dichlorodiphenyldichloroethane 0105 earth and related environmental sciences Zerovalent iron Public Health Environmental and Occupational Health General Medicine General Chemistry Pollution Carbon 020801 environmental engineering chemistry |
| Zdroj: | Chemosphere. 253 |
| ISSN: | 1879-1298 |
| Popis: | Dechlorination of dichlorodiphenyltrichloroethane (DDT) as a model compound was performed with zero-valent iron (micro-ZVI and nano-ZVI) as reductant and carbonaceous adsorbents as sink and catalyst in water. DDT is rapidly converted to dichlorodiphenyldichloroethane (DDD) in direct contact with ZVI. However, up to 90% of the DDD is transformed into non-identified, most likely oligomeric products. There is no indication of dechlorination at the aromatic rings. DDT is still rapidly dechlorinated when it is adsorbed on carbonaceous adsorbents, even though ZVI particles have no direct access to the adsorbed DDT. The carbonaceous materials function as adsorbent and catalyst for the dechlorination reaction at once. From electrochemical experiments, we deduced that direct physical contact between ZVI particles and the adsorbent is essential for enabling a chemical reaction. Electron conduction alone does not effect any dechlorination reaction. We hypothesize hydrogen species (H∗) which spill from the ZVI surface to the carbon surface and initiate reductive transformations there. The role of carbonaceous adsorbents is different for different degradation pathways: in contrast to hydrodechlorination (reduction), adsorption protects DDT from dehydrochlorination (hydrolysis). |
| Databáze: | OpenAIRE |
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