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On the use of coprostanol to identify source of nitrate pollution in groundwater

Nakagawa, Kei; Amano, Hiroki; Takao, Yuji; Hosono, Takahiro and Berndtsson, Ronny LU (2017) In Journal of Hydrology 550. p.663-668
Abstract

Investigation of contaminant sources is indispensable for developing effective countermeasures against nitrate (NO3 ) pollution in groundwater. Known major nitrogen (N) sources are chemical fertilizers, livestock waste, and domestic wastewater. In general, scatter diagrams of δ18O and δ15N from NO3 can be used to identify these pollution sources. However, this method can be difficult to use for chemical fertilizers and livestock waste sources due to the overlap of δ18O and δ15N ranges. In this study, we propose to use coprostanol as an indicator for the source of pollution. Coprostanol can be used as a fecal contamination indicator because it is a... (More)

Investigation of contaminant sources is indispensable for developing effective countermeasures against nitrate (NO3 ) pollution in groundwater. Known major nitrogen (N) sources are chemical fertilizers, livestock waste, and domestic wastewater. In general, scatter diagrams of δ18O and δ15N from NO3 can be used to identify these pollution sources. However, this method can be difficult to use for chemical fertilizers and livestock waste sources due to the overlap of δ18O and δ15N ranges. In this study, we propose to use coprostanol as an indicator for the source of pollution. Coprostanol can be used as a fecal contamination indicator because it is a major fecal sterol formed by the conversion of cholesterol by intestinal bacteria in the gut of higher animals. The proposed method was applied to investigate NO3 pollution sources for groundwater in Shimabara, Nagasaki, Japan. Groundwater samples were collected at 33 locations from March 2013 to November 2015. These data were used to quantify relationships between NO3-N, δ15N-NO3 , δ18O-NO3 , and coprostanol. The results show that coprostanol has a potential for source identification of nitrate pollution. For lower coprostanol concentrations (<30 ng L−1) in the nitrate-polluted group, fertilizer is likely to be the predominant source of NO3 . However, higher concentration coprostanol samples in the nitrate-polluted group can be related to pollution from livestock waste. Thus, when conventional diagrams of isotopic ratios cannot distinguish pollution sources, coprostanol may be a useful tool.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Coprostanol, Groundwater, Nitrate pollution, Stable isotopes
in
Journal of Hydrology
volume
550
pages
6 pages
publisher
Elsevier
external identifiers
  • scopus:85019665635
  • wos:000404816000051
ISSN
0022-1694
DOI
10.1016/j.jhydrol.2017.05.038
language
English
LU publication?
yes
id
33ca8ecd-c16b-4068-ae55-f0ca9fe9ab82
date added to LUP
2017-06-08 12:53:54
date last changed
2017-09-18 11:39:29
@article{33ca8ecd-c16b-4068-ae55-f0ca9fe9ab82,
  abstract     = {<p>Investigation of contaminant sources is indispensable for developing effective countermeasures against nitrate (NO<sub>3</sub> <sup>−</sup>) pollution in groundwater. Known major nitrogen (N) sources are chemical fertilizers, livestock waste, and domestic wastewater. In general, scatter diagrams of δ<sup>18</sup>O and δ<sup>15</sup>N from NO<sub>3</sub> <sup>−</sup> can be used to identify these pollution sources. However, this method can be difficult to use for chemical fertilizers and livestock waste sources due to the overlap of δ<sup>18</sup>O and δ<sup>15</sup>N ranges. In this study, we propose to use coprostanol as an indicator for the source of pollution. Coprostanol can be used as a fecal contamination indicator because it is a major fecal sterol formed by the conversion of cholesterol by intestinal bacteria in the gut of higher animals. The proposed method was applied to investigate NO<sub>3</sub> <sup>−</sup> pollution sources for groundwater in Shimabara, Nagasaki, Japan. Groundwater samples were collected at 33 locations from March 2013 to November 2015. These data were used to quantify relationships between NO<sub>3</sub>-N, δ<sup>15</sup>N-NO<sub>3</sub> <sup>−</sup>, δ<sup>18</sup>O-NO<sub>3</sub> <sup>−</sup>, and coprostanol. The results show that coprostanol has a potential for source identification of nitrate pollution. For lower coprostanol concentrations (&lt;30 ng L<sup>−1</sup>) in the nitrate-polluted group, fertilizer is likely to be the predominant source of NO<sub>3</sub> <sup>−</sup>. However, higher concentration coprostanol samples in the nitrate-polluted group can be related to pollution from livestock waste. Thus, when conventional diagrams of isotopic ratios cannot distinguish pollution sources, coprostanol may be a useful tool.</p>},
  author       = {Nakagawa, Kei and Amano, Hiroki and Takao, Yuji and Hosono, Takahiro and Berndtsson, Ronny},
  issn         = {0022-1694},
  keyword      = {Coprostanol,Groundwater,Nitrate pollution,Stable isotopes},
  language     = {eng},
  month        = {07},
  pages        = {663--668},
  publisher    = {Elsevier},
  series       = {Journal of Hydrology},
  title        = {On the use of coprostanol to identify source of nitrate pollution in groundwater},
  url          = {http://dx.doi.org/10.1016/j.jhydrol.2017.05.038},
  volume       = {550},
  year         = {2017},
}