Rapid Removal of Nitrate and Sulfate in Freshwater Wetland Sediments.

This article focuses on a study conducted to examine rapid removal of nitrate and sulfate in freshwater wetland sediments. Wetlands are often situated at points of ground water recharge and discharge or along streams and rivers, and thus biogeochemical processes in wetlands can affect downstream water quality, as for example by removing nutrients. Nitrate removal by wetlands has received particular attention because of the escalating problem of nitrate contamination of drinking water supplies, and the growing recognition that nitrogen pollution of rivers causes eutrophication of marine coastal waters, leading to problems such as harmful algal blooms and oxygen depletion. The purpose of this study was to investigate rates of removal of nitrate and sulfate from small wetlands of variable hydrology in the glacial landscape of southwestern Michigan. Push-pull tracer experiments were employed to evaluate the removal of nitrate and sulfate from ground water as it comes into contact with reduced wetland sediment. This is a measurement of the potential reaction rates insofar as the ground water is relatively enriched in nitrate and to a lesser extent sulfate compared to the sediment porewaters.