Phosphate dynamics in an acidic mountain stream: Interactions involving algal uptake, sorption by iron oxide, and photoreduction

Limnology and Oceanography
By: , and 

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Abstract

Acid mine drainage streams in the Rocky Mountains typically have few algal species and abundant iron oxide deposits which can sorb phosphate. An instream injection of radiolabeled phosphate (32P0,) into St. Kevin Gulch, an acid mine drainage stream, was used to test the ability of a dominant algal species, Ulothrix sp., to rapidly assimilate phosphate. Approximately 90% of the injected phosphate was removed from the water column in the 175-m stream reach. When shaded stream reaches were exposed to full sunlight after the injection ended, photoreductive dissolution of iron oxide released sorbed 32P, which was then also removed downstream. The removal from the stream was modeled as a first-order process by using a reactive solute transport transient storage model. Concentrations of 32P mass-’ of algae were typically lo-fold greater than concentrations in hydrous iron oxides. During the injection, concentrations of 32P increased in the cellular P pool containing soluble, low-molecular-weight compounds and confirmed direct algal uptake of 32P0, from water. Mass balance calculations indicated that algal uptake and sorption on iron oxides were significant in removing phosphate. We conclude that in stream ecosystems, PO, sorbed by iron oxides can act as a dynamic nutrient reservoir regulated by photoreduction.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Phosphate dynamics in an acidic mountain stream: Interactions involving algal uptake, sorption by iron oxide, and photoreduction
Series title Limnology and Oceanography
DOI 10.4319/lo.1995.40.5.0938
Volume 40
Issue 5
Year Published 1995
Language English
Publisher Wiley
Contributing office(s) Toxic Substances Hydrology Program
Description 9 p.
First page 938
Last page 946
Country United States
State Colorado
Other Geospatial Kevin's Gulch