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Profile photo of Ronny Berndtsson

Ronny Berndtsson

Professor, Dep Director, MECW Dep Scientific Coordinator

Profile photo of Ronny Berndtsson

Use of sterols to monitor surface water quality change and nitrate pollution source

Author

  • Kei Nakagawa
  • Hiroki Amano
  • R. Berndtsson
  • Yuji Takao
  • Takahiro Hosono

Summary, in English

Coprostanol was tested as ecological indicator to trace domestic and manure effluents and to investigate possible pollution sources in surface water. Pollution assessment was performed by analysing NO3−, NO2−, coprostanol (5β(H)-Cholestan-3β-ol), and cholestanol (5α(H)-Cholestan-3β-ol) in water samples from 42 sites along rivers in Shimabara and Unzen City, Japan. NO2-N concentration exceeded 0.04 mg L−1 at 2 sampling sites during winter and 6 sampling sites during summer. NO3 + NO2-N concentration exceeded 10 mg L−1 at 19 sampling sites during winter and 7 sampling sites during in summer. The highest concentration was 82.4 mg L−1 in summer. Detectable NO3-N concentration was observed in northern parts of the study area. Coprostanol concentration exceeded 700 ng L−1 (Australian Drinking Water Standard) at 8 sampling points during winter and 6 sampling sites during summer. At 10 and 5% of the sampling sites, both nitrate and coprostanol concentration exceeded drinking water standard during winter and summer, respectively. The percentage of sampling sites where either concentration was above drinking water standard was 45% during winter and 22% during summer season. However, depending on sampling site, the relationships between nitrate and coprostanol concentrations showed different patterns. The sterol ratio exceeded 0.5 at 17 sampling sites during winter and 14 sampling sites during summer. Thus, it was confirmed that fecal pollution is present in the studied surface water. A method to distinguish between principal pollution sources was developed by separating four areas in a nitrate concentration and sterol ratio plot. Results show that sampled data could be reasonably classified into appropriate polluted/non-polluted groups. Thus, coprostanol and sterol ratio can be used as indicators to distinguish between different nitrate pollution sources in surface water.

Department/s

  • Centre for Advanced Middle Eastern Studies (CMES)
  • MECW: The Middle East in the Contemporary World
  • Division of Water Resources Engineering

Publishing year

2019-12

Language

English

Publication/Series

Ecological Indicators

Volume

107

Document type

Journal article

Publisher

Elsevier

Topic

  • Oceanography, Hydrology, Water Resources
  • Analytical Chemistry

Keywords

  • Coprostanol
  • Nitrate pollution
  • Sterol ratio
  • Surface water

Status

Published

ISBN/ISSN/Other

  • ISSN: 1470-160X