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Photodegradation in natural waters of nitrosamines and nitramines derived from CO2 capture plant operation

Photodegradation in natural waters of nitrosamines and nitramines derived from CO2 capture plant operation

Category
Academic article
Abstract
Amine solvents used in post combustion CO2 capture (PCCC) plants react with NOx, forming carcinogenic nitrosamine and nitramine compounds. These can be emitted to the atmosphere, undergoing deposition to aquatic and terrestrial environments. In the current study, the hydrolytic and photolytic degradation of nine nitramines and nitrosamines identified as possible degradation products of 2-monoethanolamine and piperazine solvents are studied. Nitrosamines and nitramines are generally resistant to hydrolysis, although nitrosopiperazine and piperazine nitramine both undergo up to 50 % degradation at 50 °C and pH 7, but not at lower temperatures or other pH values. Owing to absorbance at ~340 nm, the nitrosamines degrade rapidly in aqueous solution when exposed to sunlight (half-lives in the range 6-11 minutes), whilst nitramines are photolytically stable. Light screening by natural organic matter (1-100 mg/L) lead to an ~3-fold decrease in nitrosodiethanolamine (NDELA; 1 mg/L) degradation rate. A theoretical study indicates environmentally relevant concentrations of NDELA may be persistent due to competition with NOM for photons. The main photodegradation products are identified for each nitrosamine, and degradation mechanisms suggested.
Client
  • Research Council of Norway (RCN) / 203095
Language
English
Affiliation
  • SINTEF Ocean / Miljø og nye ressurser
  • SINTEF Industry / Biotechnology and Nanomedicine
  • SINTEF Industry / Process Technology
Year
Published in
International Journal of Greenhouse Gas Control
ISSN
1750-5836
Publisher
Elsevier
Volume
32
Page(s)
106 - 114