Effect of pH and Redox Potential on Concentration of Dissolved Nutrients in an Estuarine Sediment1
- R. D. De Laune,
- C. N. Reddy and
- W. H. Patrick2
A study was conducted on sediment suspensions maintained under conditions of controlled pH (5.0, 6.5, and 8.0) and redox potentials (−200, 0, 250, and 500 mV) to determine the effect of these parameters on concentrations of dissolved organic C, P, NH4+, Fe, and Mn in an estuarine sediment. Concentration of these nutrients was strongly influenced by changes in sediment pH and redox potential. Dissolved organic C increased from 42 µg ml−1 at pH 5.0 and 500 mV, to 93 µg ml−1 at pH 8.0 and −200 mV. Soluble P, NH4+, Fe, and Mn concentrations increased with decreasing sediment redox potential and pH. Phosphorus concentrations ranged from 0.002 µg ml−1 at pH 8.0 and 500 mV, to 0.215 µg ml−1 at pH 5.0 and −200 mV. Iron and manganese concentrations ranged from <0.1 µg ml−1 at pH 8.0 and 500 mV, to 101 and 13 µg ml−1, respectively, at pH 5.0 and −200 mV.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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