Nitrate and ferrous iron concentrations in the lower Burdekin aquifers: assessing denitrification potential

T. Thayalakumaran, P.B. Charlesworth, Keith Bristow, R.J. van Bemmelen, J. Jaffres

Research output: Book chapter/Published conference paperConference paper

Abstract

The lower Burdekin is one of Australia's premier irrigation districts with more than 80,000 ha ofsugarcane and other crops. Because it is located adjacent to the Great Barrier Reef Lagoon, there is stronginterest in understanding the fate of nitrogen applied as fertiliser. Natural denitrification is increasinglyrecognised for its ability to reduce nitrate concentrations in groundwater and we therefore analysed watersamples for a range of constituents (nitrate, ferrous iron, dissolved oxygen, redox potential, pH) from 57monitoring bores to investigate the denitrification potential of the lower Burdekin aquifers. Nitrateconcentrations ranged from <0.1 to 14.4 mg/L NO3-N (three times the ANZECC environmental standardof 5 mg/L). Ferrous concentration varied from 1 to 360 mg/L, dissolved oxygen was < 2 mg/L, redoxpotential varied from -120 to +235 mV, and pH ranged from 5.9 to 7.6. Elevated nitrate levels wereobserved in 16% of the bores located mostly in the Home Hill area. These areas also had low ferrouslevels. High ferrous levels were found mostly in the Ayr area and at shallow depths. The data in generalshowed an inverse relationship between nitrate and iron, and between nitrate and ammonium.Furthermore, undetectable amounts of nitrate were measured in the nested bores located along the coast.These geochemical conditions favour the presence of ferrous iron and a reduced environment conduciveto denitrification. These results suggest that denitrification is one of the mechanisms involved in reducingthe amount of nitrate in the lower Burdekin aquifers and hence reducing the potential for nitrate to movefrom the groundwater into the near-shore marine environment.
LanguageEnglish
Title of book or conference publicationSuperSoil 2004 Conference 3rd Australian New Zealand Soils Conference
EditorsBalwant Singh
Place of PublicationSydney
PublisherThe Regional Institute Ltd
Pages1-9
Number of pages9
ISBN (Electronic)1920842268
Publication statusPublished - 2004
EventSuperSoil 2004 Conference 3rd Australian New Zealand Soils Conference - Sydney, Australia
Duration: 05 Dec 200409 Dec 2004

Conference

ConferenceSuperSoil 2004 Conference 3rd Australian New Zealand Soils Conference
CountryAustralia
Period05/12/0409/12/04

Fingerprint

denitrification
aquifer
nitrate
iron
dissolved oxygen
groundwater
redox potential
barrier reef
marine environment
lagoon
ammonium
fertilizer
irrigation
crop
coast
nitrogen

Cite this

Thayalakumaran, T., Charlesworth, P. B., Bristow, K., van Bemmelen, R. J., & Jaffres, J. (2004). Nitrate and ferrous iron concentrations in the lower Burdekin aquifers: assessing denitrification potential. In B. Singh (Ed.), SuperSoil 2004 Conference 3rd Australian New Zealand Soils Conference (pp. 1-9). Sydney: The Regional Institute Ltd.
Thayalakumaran, T. ; Charlesworth, P.B. ; Bristow, Keith ; van Bemmelen, R.J. ; Jaffres, J. / Nitrate and ferrous iron concentrations in the lower Burdekin aquifers : assessing denitrification potential. SuperSoil 2004 Conference 3rd Australian New Zealand Soils Conference. editor / Balwant Singh. Sydney : The Regional Institute Ltd, 2004. pp. 1-9
@inproceedings{2c558e6becf049219cea8b48cfd0277f,
title = "Nitrate and ferrous iron concentrations in the lower Burdekin aquifers: assessing denitrification potential",
abstract = "The lower Burdekin is one of Australia's premier irrigation districts with more than 80,000 ha ofsugarcane and other crops. Because it is located adjacent to the Great Barrier Reef Lagoon, there is stronginterest in understanding the fate of nitrogen applied as fertiliser. Natural denitrification is increasinglyrecognised for its ability to reduce nitrate concentrations in groundwater and we therefore analysed watersamples for a range of constituents (nitrate, ferrous iron, dissolved oxygen, redox potential, pH) from 57monitoring bores to investigate the denitrification potential of the lower Burdekin aquifers. Nitrateconcentrations ranged from <0.1 to 14.4 mg/L NO3-N (three times the ANZECC environmental standardof 5 mg/L). Ferrous concentration varied from 1 to 360 mg/L, dissolved oxygen was < 2 mg/L, redoxpotential varied from -120 to +235 mV, and pH ranged from 5.9 to 7.6. Elevated nitrate levels wereobserved in 16{\%} of the bores located mostly in the Home Hill area. These areas also had low ferrouslevels. High ferrous levels were found mostly in the Ayr area and at shallow depths. The data in generalshowed an inverse relationship between nitrate and iron, and between nitrate and ammonium.Furthermore, undetectable amounts of nitrate were measured in the nested bores located along the coast.These geochemical conditions favour the presence of ferrous iron and a reduced environment conduciveto denitrification. These results suggest that denitrification is one of the mechanisms involved in reducingthe amount of nitrate in the lower Burdekin aquifers and hence reducing the potential for nitrate to movefrom the groundwater into the near-shore marine environment.",
keywords = "DNRA, DO, DOC, Eh, Geochemical conditions",
author = "T. Thayalakumaran and P.B. Charlesworth and Keith Bristow and {van Bemmelen}, R.J. and J. Jaffres",
note = "Imported on 03 May 2017 - DigiTool details were: publisher = Sydney: The Regional Institute Ltd, 2004. editor/s (773b) = Dr Balwant Singh; Event dates (773o) = 5-9 December 2004; Parent title (773t) = SuperSoil 2004 Conference 3rd Australian New Zealand Soils Conference.",
year = "2004",
language = "English",
pages = "1--9",
editor = "Balwant Singh",
booktitle = "SuperSoil 2004 Conference 3rd Australian New Zealand Soils Conference",
publisher = "The Regional Institute Ltd",

}

Thayalakumaran, T, Charlesworth, PB, Bristow, K, van Bemmelen, RJ & Jaffres, J 2004, Nitrate and ferrous iron concentrations in the lower Burdekin aquifers: assessing denitrification potential. in B Singh (ed.), SuperSoil 2004 Conference 3rd Australian New Zealand Soils Conference. The Regional Institute Ltd, Sydney, pp. 1-9, SuperSoil 2004 Conference 3rd Australian New Zealand Soils Conference, Australia, 05/12/04.

Nitrate and ferrous iron concentrations in the lower Burdekin aquifers : assessing denitrification potential. / Thayalakumaran, T.; Charlesworth, P.B.; Bristow, Keith; van Bemmelen, R.J.; Jaffres, J.

SuperSoil 2004 Conference 3rd Australian New Zealand Soils Conference. ed. / Balwant Singh. Sydney : The Regional Institute Ltd, 2004. p. 1-9.

Research output: Book chapter/Published conference paperConference paper

TY - GEN

T1 - Nitrate and ferrous iron concentrations in the lower Burdekin aquifers

T2 - assessing denitrification potential

AU - Thayalakumaran, T.

AU - Charlesworth, P.B.

AU - Bristow, Keith

AU - van Bemmelen, R.J.

AU - Jaffres, J.

N1 - Imported on 03 May 2017 - DigiTool details were: publisher = Sydney: The Regional Institute Ltd, 2004. editor/s (773b) = Dr Balwant Singh; Event dates (773o) = 5-9 December 2004; Parent title (773t) = SuperSoil 2004 Conference 3rd Australian New Zealand Soils Conference.

PY - 2004

Y1 - 2004

N2 - The lower Burdekin is one of Australia's premier irrigation districts with more than 80,000 ha ofsugarcane and other crops. Because it is located adjacent to the Great Barrier Reef Lagoon, there is stronginterest in understanding the fate of nitrogen applied as fertiliser. Natural denitrification is increasinglyrecognised for its ability to reduce nitrate concentrations in groundwater and we therefore analysed watersamples for a range of constituents (nitrate, ferrous iron, dissolved oxygen, redox potential, pH) from 57monitoring bores to investigate the denitrification potential of the lower Burdekin aquifers. Nitrateconcentrations ranged from <0.1 to 14.4 mg/L NO3-N (three times the ANZECC environmental standardof 5 mg/L). Ferrous concentration varied from 1 to 360 mg/L, dissolved oxygen was < 2 mg/L, redoxpotential varied from -120 to +235 mV, and pH ranged from 5.9 to 7.6. Elevated nitrate levels wereobserved in 16% of the bores located mostly in the Home Hill area. These areas also had low ferrouslevels. High ferrous levels were found mostly in the Ayr area and at shallow depths. The data in generalshowed an inverse relationship between nitrate and iron, and between nitrate and ammonium.Furthermore, undetectable amounts of nitrate were measured in the nested bores located along the coast.These geochemical conditions favour the presence of ferrous iron and a reduced environment conduciveto denitrification. These results suggest that denitrification is one of the mechanisms involved in reducingthe amount of nitrate in the lower Burdekin aquifers and hence reducing the potential for nitrate to movefrom the groundwater into the near-shore marine environment.

AB - The lower Burdekin is one of Australia's premier irrigation districts with more than 80,000 ha ofsugarcane and other crops. Because it is located adjacent to the Great Barrier Reef Lagoon, there is stronginterest in understanding the fate of nitrogen applied as fertiliser. Natural denitrification is increasinglyrecognised for its ability to reduce nitrate concentrations in groundwater and we therefore analysed watersamples for a range of constituents (nitrate, ferrous iron, dissolved oxygen, redox potential, pH) from 57monitoring bores to investigate the denitrification potential of the lower Burdekin aquifers. Nitrateconcentrations ranged from <0.1 to 14.4 mg/L NO3-N (three times the ANZECC environmental standardof 5 mg/L). Ferrous concentration varied from 1 to 360 mg/L, dissolved oxygen was < 2 mg/L, redoxpotential varied from -120 to +235 mV, and pH ranged from 5.9 to 7.6. Elevated nitrate levels wereobserved in 16% of the bores located mostly in the Home Hill area. These areas also had low ferrouslevels. High ferrous levels were found mostly in the Ayr area and at shallow depths. The data in generalshowed an inverse relationship between nitrate and iron, and between nitrate and ammonium.Furthermore, undetectable amounts of nitrate were measured in the nested bores located along the coast.These geochemical conditions favour the presence of ferrous iron and a reduced environment conduciveto denitrification. These results suggest that denitrification is one of the mechanisms involved in reducingthe amount of nitrate in the lower Burdekin aquifers and hence reducing the potential for nitrate to movefrom the groundwater into the near-shore marine environment.

KW - DNRA

KW - DO

KW - DOC

KW - Eh

KW - Geochemical conditions

M3 - Conference paper

SP - 1

EP - 9

BT - SuperSoil 2004 Conference 3rd Australian New Zealand Soils Conference

A2 - Singh, Balwant

PB - The Regional Institute Ltd

CY - Sydney

ER -

Thayalakumaran T, Charlesworth PB, Bristow K, van Bemmelen RJ, Jaffres J. Nitrate and ferrous iron concentrations in the lower Burdekin aquifers: assessing denitrification potential. In Singh B, editor, SuperSoil 2004 Conference 3rd Australian New Zealand Soils Conference. Sydney: The Regional Institute Ltd. 2004. p. 1-9