Effect of hydrogen sulfide on phosphorus lability in lake sediments amended with drinking water treatment residuals.

The use of drinking water treatment residuals (WTRs) to immobilize P in sediments is a novel approach for lake restoration. However, the lability of P in WTRs-amended sediments may vary with many factors, e.g., hydrogen sulfide content. Earlier works in our laboratory have demonstrated that WTRs are effective sorbents for hydrogen sulfide in water. Thus, we hypothesized that the lability of P in WTRs-amended sediments would not be increased by hydrogen sulfide. The results of this work suggested that this hypothesis was tenable. Compared to the raw sediments, the amended sediments had significantly lower P desorption potential in the presence of hydrogen sulfide at different times, pH and concentrations. Moreover, the amended sediments were also better able to adsorb hydrogen sulfide. In the amended sediments, the P, which was easily desorbed due to the effect of hydrogen sulfide, was transformed into the Fe/Al bound P.