Organic Phosphorus Sequestration in Subtropical Treatment Wetlands
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- 作者：Benjamin L. Turner ; Susan Newman ; and Jana M. Newman
- 刊名：Environmental Science & Technology
- 出版年：2006
- 出版时间：February 1, 2006
- 年：2006
- 卷：40
- 期：3
- 页码：727 - 733
- 全文大小：273K
- 年卷期：v.40,no.3(February 1, 2006)
- ISSN：1520-5851
文摘
Diffuse phosphorus pollution is commonly remediated bydiverting runoff through treatment wetlands to sequesterphosphorus into soil layers. Much of the sequesteredphosphorus occurs in organic forms, yet our understandingof its chemical nature is limited. We used NaOH-EDTAextraction and solution 31P NMR spectroscopy to speciateorganic phosphorus sequestered in a large treatmentwetland (STA-1W) in Florida, USA. The wetland wasconstructed on previously farmed peat and was designedto remove phosphorus from agricultural runoff prior todischarge into the Everglades. Unconsolidated benthic flocthat had accumulated during the 9-year operation of thewetland was sampled along transects through two connectedcells dominated by cattail (Typha dominigensis Pers.)and an additional cell colonized by submerged aquaticvegetation, including southern water nymph (Najasguadalupensis (Spreng.) Magnus) and coontail (Ceratophyllumdemersum L.). Organic phosphorus was a greaterproportion of the sequestered phosphorus in the cattailmarsh compared to the submerged aquatic vegetationwetland, but occurred almost exclusively as phosphatediesters and their alkaline hydrolysis products. It was thereforemarkedly different from the organic phosphorus inmineral soils, which is dominated typically by inositolphosphates. Phosphate diesters are readily degradable inmost soils, raising concern about the long-term fate oforganic phosphorus in treatment wetlands. Further studiesare now necessary to assess the stability of the sequesteredorganic phosphorus in response to biogeochemical andhydrological perturbation.