wAbstract
@The presence of nitrate in the hypolimnion of the eutrophic,
dimictic Upper Mystic Lake has been previously shown to suppress
the release of arsenic from lake sediments during seasonal anoxia,
in large part by oxidizing iron (II) and producing iron oxyhydroxides
that sorb inorganic arsenic. Because of the importance of internal
phosphorus loading in the phosphorus budget of many eutrophic
lakes, the chemical similarities between phosphate and arsenate,
and the need to account for internal phosphorus loading as part
of many lake restoration strategies, we carried out measurements
to determine if the presence of nitrate also suppressed the release
of phosphorus from the sediments of this lake during anoxia. Observations
showed that this was the case. Arsenic, phosphorus, and iron(II)
concentrations were strongly correlated in the water column, as
expected, and the depths below which phosphorus and iron concentrations
increased relative to epilimnetic values was predicted by the
depth at which nitrate concentration approached zero. The results
suggest that knowledge of a lake's nitrogen budget may be a useful
tool in the design of lake that remediation efforts, even though
phosphorus is typically the limiting nutrient.
Keywords: Phosphorus; Nitrate; Eutrophication; Arsenic; Ironx
1. Introduction
2. Methods
3. Results
@3.1. Correlation of P and As concentrations in the water
column
@3.2. Spatiotemporal pattern of P, O2, Fe,
and NO3- concentrations
4. Discussion
5. Conclusions
Acknowledgement
References