Seawater induced release and transformation of organic and inorganic phosphorus from river sediments

Abstract

This paper reports an investigation of the release of organic and inorganic phosphorus from a riverine sediment subjected to salinity conditions typical of estuarine mixing. Freshwater sediment was mixed with filtered river water in a thermostatted reactor, and allowed to equilibrate under aerobic conditions for 3 days. Salinity was then increased in a stepwise manner by addition of filtered low-nutrient seawater over a period of 4 days. A control experiment was performed in a second reactor by substituting ultrapure water for seawater. Using a flow injection analysis method for measurement of filterable reactive phosphorous (FRP, the so-called inorganic fraction) and filterable organic phos..