Distribution of Nitrate in Different Aquifers in the Urban District of Zhanjiang, China.

The study of NO3 (-) contamination in groundwater is becoming increasingly significant as high concentrations of NO3 (-) in groundwater can do damage to public health. Nitrate pollution in the shallow, middle-deep and deep aquifers in the urban district of Zhanjiang was studied using the ordinary Kriging interpolation method combined with hydrochemical and correlation analyses in 2011. The results showed NO3 (-) pollution was present in the shallow groundwater, with average concentrations of 47.43 mg/L and standard deviation of 50.92. Nitrate concentrations were lower in middle-deep and deep aquifers, with average concentrations of 2.36, 0.80 mg/L, and standard deviation of 6.23, 0.93, respectively. Nitrate was correlated with Na(+) + K(+), Mg(2+), Cl(-) and SO4 (2-) in the shallow aquifer, and the spatial distributions of NO3 (-) exhibited a same pattern with TDS in the shallow aquifer, the NO3 (-) pollution in the middle-deep and deep aquifers is less serious.