University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Hülya Hazler
(2015):
Einfluss von Zuschlagstoffen auf den reduktiven Abbau von chlorierten Kohlenwasserstoffen mit nullwertigem Eisen..
Master / Diploma Thesis - Institut für Bodenforschung (IBF),
BOKU-Universität für Bodenkultur,
pp 125.
UB BOKU
obvsg
- Abstract:
- It is assumed that about one third of all substantielly contaminated sites in Europe contain chlorinated hydrocarbons, such as Trichloroethylene (TCE). The reductive dechlorination of TCE with nanoscale zero-valent iron (nZVI), enables an effective sanitation of contaminated soils and aquifers underneath buildings. nZVI can be directly injected via jet grouting. As part of the research project ‘Halocrete’ and the following work, this method was adapted for the in-situ chemical reduction. The aim of this study was to develop a suitable setup, which would allow an anoxic operation of column tests. In addition, the influence of shaking, clay mineral additives (bentonite, concresol), sulfur and various nanoiron suspensions on TCE-degradation kinetics in batch experiments was investigated. The column tests showed that it was not possible to produce oxygen-free solutions and to determine the oxygen concentration in the glass columns with the chosen approach. In addition, an iron migration along the flow direction of the glass columns, was observed. In tests which were layered with additional fine quartz sand, the iron migration was inhibited. The batch experiments showed that after 48 hours without shaking, the observed rate constant [k(obs, 48h)] was significantly lower than the observed rate constant of vials which were shaken. An accelerated TCE degradation occurred by adding clay mineral additives or different sulfur concentrations. A combination of both resulted in the fastest TCE-degradation. The Nanofer 25 suspensions with sulfur (which were prepared on-site by the company Nanoiron s.r.o.) led to a slower reduction of TCE in comparison to the Nanofer 25 suspensions, which as part of my work, were supplemented with the same amount of sulfur shortly before beginning the experiment.
- Beurteilende(r):