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Author(s): Konrad Stemmler (corresponding author) [1]; Markus Ammann [1]; Chantal Donders [1, 3]; Jörg Kleffmann [2]; Christian George [4] Nitrous acid is a significant photochemical precursor of the hydroxyl radical [...]

Researchers from the Swiss Federal Institute for Environmental Science and Technology investigated the degradation of atrazine by ozone and OH radicals to be used as a valuable tool in the treatment of drinking water.

An Escherichia coli whole-cell biosensor was developed for linear alkane detection through the transcriptional fusion of Vibrio harveji promotorless luxAB genes and Pseudomonas oleovorans alkB promoter. Standardized and optimized assays were then employed in evaluating the biosensor strain's ability to detect octane concentrations. The biosensor was also found to be useful in estimating linear akane concentrations in groundwater samples contaminated with oil.

The hydroxyl radical (OH)-initiated oxidation of 2-ethoxyethanol yields as major products ethyl formate, ethylene glycol monoformate, ethylene glycol monoacetate and ethoxyacetaldehyde. A mechanism involving initial OH attack at the three CH2 groups in 2-ethoxyethanol and subsequent reactions of the resulting alkyl and alkoxy radicals is proposed to explain the product distribution. Preferential C-C cleavage is involved in the decomposition reactions of the alkoxy radicals from 2-ethoxyethanol.

The photochemical reactivity of phenols to different types of dissolved natural organic material (DNOM) and aromatic ketones was investigated to elucidate the transformation kinetics of phenols in water. The results indicated that excited triplet states of DNOM acted as photooxidants for different methyl and methoxy phenols in sunlit waters. Other DNOM-derived photooxidants with relatively long lifetimes influenced phenol transformation rates.

HFC-365mfc (1,1,1,3,3-pentafluorobutane)is an industrial chemical used for polyurethane foam blowing. From early 2003, HFC-365mfc has been commercially produced as a substitute for HCFC-141b, whose use in Europe has been banned since January 2004. We describe the first detection of HFC-365mfc in the atmosphere and report on a 2 year long record at the high Alpine station of Jungfraujoch (Switzerland) and the Atlantic coast station of Mace Head (Ireland). The measurements at Jungfraujoch are used to estimate the central European emissions of HFC-365mfc, HCFC-141b, and CFC-11. For HFC-365mfc, we estimate the central European emissions (Germany, France, Italy, Switzerland, The Netherlands, Belgium, and Luxembourg) in 2003 and 2004 as 400–500 tonnes year-1. These emissions are about one-third lower on a per capita basis than what we estimate from the Mace Head measurements for the total of Europe. The estimated emissions of HCFC-141b for central Europe are higher (i.e., 7.2–3.5 ktonnes year-1) with a decreasing trend in the period from 2000 to 2004. Residual emissions of CFC-11 are estimated at 2.4–4.7 ktonnes year-1 in the same time period. The Po Valley (northern Italy) appears to be a main source region for HFC-365mfc and for the former blowing agents HCFC-141b and CFC-11. In 2004, the emissions of HFC-365mfc arose from a wider region of Europe, which we attribute to an increased penetration of HFC-365mfc into the European market. [ABSTRACT FROM AUTHOR]