eprintid: 16746
rev_number: 11
eprint_status: archive
userid: 1134
dir: disk0/00/01/67/46
datestamp: 2014-04-16 13:12:35
lastmod: 2014-04-23 09:51:22
status_changed: 2014-04-16 13:12:35
type: doctoralThesis
metadata_visibility: show
creators_name: Krause, Torsten
title: Natural Occurrence of Volatile Mono-/Polyhalogenated amd Aromatic/Heteroaromatic Hydrocarbons in Hypersaline Environments
subjects: 550
divisions: 121000
adv_faculty: af-12
abstract: Volatile compounds are important substances for tropospheric and stratospheric chemistry.
Anthropogenic sources of specific gases causing greenhouse effect, stratospheric ozone
depletion, groundlevel ozone formation and aerosol formation are well known. Additionally,
many natural sources, like oceans, wetlands and forests, have been investigated and assessed
for their atmospheric impact previously.
While emissions from natural sources are often affiliated to biotic mechanisms, model
reactions demonstrated also the importance of abiotic reactions. As such furan formation from
catechol was successfully accomplished in this work using Fenton chemistry with a well
defined biomimetic bispidine Fe2+ complex. Furthermore, abiotic formation of ethylfuran
from ethylcatechol was demonstrated.
The work in hand also deals with the amalgamation of model reaction and the natural release
of volatile compounds from Western Australian salt lakes and the Dead Sea.
On the one hand, Fe2+ was determined as the predominant active iron species in most natural
hypersaline ecosystems. On the other hand, the release of several aromatic and nonaromatic
hydrocarbons, furanoic compounds, sulfur and selenide containing compounds and
halogenated compounds was investigated in correlation with geochemical parameters like pH,
iron and organic carbon content. Benzene, toluene, ethylbenzene and xylene emissions,
normally attributed to anthropogenic sources, correlated significantly with the iron content of
Australian salt lake sediments demonstrating their genuine natural abundance. The same was
observed for furan and hitherto mostly unnoticed n-alkyl chlorides with a C3-C8 carbon
structure. Furthermore, a connection between emissions of methylfurans and their
homologoues methylthiophenes was observed indicating a mutual precursor and similar
formation mechanism in the soils/sediments.
Aside from various known natural chlorinated, brominated and iodinated compounds, new
compounds were identified like 3-chlorofuran. Additionally, natural tetrachloromethane
formation in acidic salt lakes was postulated supported by various results.
Relevance of these compounds for the atmospheric chemistry was assessed with regard to
ultrafine particle formation in Western Australia and reactive IO/BrO over the Dead Sea.
date: 2014
id_scheme: DOI
id_number: 10.11588/heidok.00016746
ppn_swb: 165498244X
own_urn: urn:nbn:de:bsz:16-heidok-167464
date_accepted: 2014-04-07
advisor: HASH(0x564e138d0e00)
language: eng
bibsort: KRAUSETORSNATURALOCC2014
full_text_status: public
citation:   Krause, Torsten  (2014) Natural Occurrence of Volatile Mono-/Polyhalogenated amd Aromatic/Heteroaromatic Hydrocarbons in Hypersaline Environments.  [Dissertation]     
document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/16746/1/Dissertation%20Torsten%20Krause.pdf