Photodegradation of micropollutants using V-UV/UV-C processes: Triclosan as a model compound

Publikation: Beiträge in ZeitschriftenZeitschriftenaufsätzeForschungbegutachtet

Authors

  • Yuval Alfiya
  • Eran Friedler
  • Janin Westphal
  • Oliver Olsson
  • Yael Dubowski

Non-potable reuse of treated wastewater is becoming widespread as means to address growing water scarcity. Removal of micropollutants (MPs) from such water often requires advanced oxidation processes using [rad]OH radicals. [rad]OH can be generated in-situ via water photolysis under vacuum-UV (λ < 200 nm) irradiation. The aim of this study was to investigate the potential of unmasking V-UV radiation from low pressure Hg lamps (emitting at 185 and 254 nm), commonly used in decentralized treatment systems, for enhancing MPs removal efficiency. Triclosan, a biocide of limited biodegradability, served as a model compound for MPs that are not very biodegradable. Its degradation kinetics and identification of intermediate products were investigated under 254 nm and under combined 254/185 nm irradiation both in dry thin films and in aqueous solutions. In the latter, degradation was faster under combined 254/185 nm radiation, although the 185 nm radiation accounted for only 4% of the total UV light intensity. In contrast, triclosan photodegradation in dry film did not show significant differences between these irradiation wavelengths, suggesting that the enhanced degradation of dissolved triclosan under combined radiation is mainly due to oxidation by [rad]OH formed via water photolysis under V-UV. This conclusion was supported by slower TCS degradation in aqueous solution when methanol was added as [rad]OH scavenger. Under both irradiation types (254, 254/185 nm) three transformation products (TPs) were identified: 2,8-dichlorodibenzo-p-dioxin, 5-chloro-2-(4- or 2-chlorophenoxy)phenol, and 2-hydroxy-8-chlorodibenzodioxin. In-silico QSAR toxicity assessment predicted potential toxicity and moderate-to-low biodegradability of these TPs. Removal of these TPs was faster under 254/185 nm irradiation. Considering the low cost, simple operation (i.e. no chemicals addition) and small size of such low-pressure mercury lamps, this is a promising direction. Further investigation of the process in flow-through reactors and real wastewater/greywater effluent is needed for its future implementation in small on-site systems for post-treatment of persistent pollutants.

OriginalspracheEnglisch
ZeitschriftThe Science of The Total Environment
Jahrgang601-602
Seiten (von - bis)397-404
Anzahl der Seiten8
ISSN0048-9697
DOIs
PublikationsstatusErschienen - 01.12.2017

DOI

Zuletzt angesehen

Publikationen

  1. Algorithmic Catastrophe - the Revenge of Contingency
  2. Diversity of Play
  3. Jordan Canonical Form for Solving the Fault Diagnosis and Estimation Problems
  4. Quasi-in-situ observation of microstructure at the friction interface
  5. Structuring Sustainability Reports for Environmental Standards with LLMs guided by Ontology
  6. A path to clean water
  7. How Big Does Big Data Need to Be?
  8. Forest structure and heterogeneity increase diversity and alter composition of host–parasitoid networks
  9. Usage pattern-based exposure screening as a simple tool for the regional priority-setting in environmental risk assessment of veterinary antibiotics
  10. Release of monomers from four different composite materials after halogen and LED curing
  11. Modelling scenarios to identify a combined sediment-water management strategy for the large reservoirs of the Tuyamuyun hydro-complex
  12. Consular Assistance: Rights, Remedies, and Responsibility Comments on the ICJ's Judgment in the LaGrand Case
  13. Understanding Similarities and Differences of Digital Health Platforms
  14. Effect of salinity-changing rates on filtration activity of mussels from two sites within the Baltic Mytilus hybrid zone
  15. Der "fachdidaktische Code" der Lebenswelt- und/oder (?) Situationsorientierung
  16. Putting Architecture in its Social Space: the Fields and Skills of Planning Maastricht
  17. Das relationale Apriori Wiens / Das städtische Apriori des Relationalismus
  18. Monitoring of methotrexate chlorination in water
  19. Time for the Environment: The Tutzing Time Ecology Project
  20. Evidence for singlet state β cleavage in the photoreaction of α-(2,6-dimethoxyphenoxy)-acetophenone inferred from time-resolved CIDNP spectroscopy
  21. The complementary relationship of exploration and exploitation in professional service firms: An exploratory study of IT consulting firms
  22. Multivariate Optimization of Analytical Methodology and a First Attempt to an Environmental Risk Assessment of β-Blockers in Hospital Wastewater
  23. The rise and decline of regional power
  24. Modeling Interactions and Dependencies in Production Planning and Control
  25. How to specify the structure of substituted blade-like zigzag diamondoids
  26. X Machina and the World of Tomorrow