Natalie Lamagna
Charles A. Cravotta III
William H. J. Strosnider
Peter M. Smyntek
2022
<p><span>Hydrous ferric-oxide (HFO) coatings on streambed sediments may attenuate dissolved phosphate (PO</span><sub>4</sub><span>) concentrations at acidic to neutral pH conditions, limiting phosphorus (P) transport and availability in aquatic ecosystems. Mesh-covered tiles on which “natural” HFO from abandoned mine drainage (AMD) had precipitated were exposed to treated municipal wastewater (MWW) effluent or a mixture of stream water and effluent. Between 42 and 99% of the dissolved P in effluent was removed from the water to a thin coating (~2 μm) of HFO on the mesh. Geochemical equilibrium model results predicted the removal of 76 to 99% of PO</span><sub>4</sub><span> from the water by adsorption to the HFO, depending on the HFO quantity, initial PO</span><sub>4</sub><span> concentration, and pH. The measurements and model results indicated the capacity for P removal decreased as the concentration of P associated with the HFO increased. Continuing accumulation of HFO from upstream AMD sources replenish the in-stream capacity for P attenuation below the MWW discharge. This indicates AMD pollution may conceal P inputs and limit the amount of dissolved P transported to downstream ecosystems. However, HFO-rich sediments also represent a potential source of “legacy” P that could confound management practices intended to decrease nutrient and metal loadings.</span></p>
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10.1016/j.scitotenv.2021.152672
en
Elsevier
Mine drainage precipitates attenuate and conceal wastewater-derived phosphate pollution in stream water
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