The Effect of pH on the Release of Phosphorus from Potomac River Sediment 1987
- Published:
- November 1, 1987
- Originator:
- Chesapeake Bay Program
Recurring algal blooms in the tidal freshwater portion of the Potomac River indicate an association between chlorophyll a, high phosphorus concentrations, and high pH of the water. In the present study, the relase of phosphorus from sediments, as a function of overlying water pH was measured at eight locations. Phosphate release under aerobic conditions was found to increase as a function of overlying water pH. The increased release of phosphate at high pH is likely due to solubilization from iron and aluminum phosphate complexes. The release of amonia from Potomac River sediments increased with increasing pH; the uptake of nitrate by the sediments generally increased with increasing pH. Denitrification appears to be an important sink for nitrogen in this portion of the Potomac River, and is removing an amount of nitrogen equivalent to approximately 35% of the nitrogen loading to this portion of the river.