ANALYSIS OF NITRATES AND NITRITES IN SUBSOIL AND GROUND WATER SAMPLES IN SWAZILAND

  • A. O. Fadiran* Department of Chemistry, University of Swaziland, P/Bag 4, Kwaluseni, Swaziland
  • W. F. Mdlulie Department of Chemistry, University of Swaziland, P/Bag 4, Kwaluseni, Swaziland
  • B. K. Simelane Department of Chemistry, University of Swaziland, P/Bag 4, Kwaluseni, Swaziland
Keywords: Shallow wells, Boreholes, Springs, Nitrate fertilizers, Microbial conversion of nitrate, Methemoglobinemia, Maximum contaminant level (MCL)

Abstract

The concentrations of nitrate as nitrogen (NO3–N) in mg/L and nitrite as nitrogen (NO2–N) in µg/L were determined in water samples from 60 boreholes, 21 shallow wells and 7 springs located in the four regions of the country. For all the 88 sampling points nitrate levels vary within 0.05 ± 0.00 – 28.44 ± 0.80 mg/L NO3–N, out of which 10.22% have mg/L NO3–N ≥ MCL (maximum contaminant level) of 10 mg/L NO3–N. Shallow wells recorded the highest NO3–N% ≥ MCL of 20.0% followed by boreholes with NO3–N % ≥ MCL of 8.33% while for springs, the NO3–N % ≥ MCL was zero. On the other hand, NO2–N (µg/L) from all the sampling points vary within (ND/0.30 ± 0.00 – 297.0 ± 0.50) µg/L NO2–N, which were far below the recommended MCL of 1 mg/L (= 1000 µg/L).

KEY WORDS: Shallow wells, Boreholes, Springs, Nitrate fertilizers, Microbial conversion of nitrate, Methemoglobinemia, Maximum contaminant level (MCL)

Bull. Chem. Soc. Ethiop. 2005, 19(1), 45-54.
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