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Bioavailability of Organic Phosphorus in a Submerged Aquatic Vegetation–Dominated Treatment Wetland
Author(s) -
Pant H. K.,
Reddy K. R.,
Dierberg F. E.
Publication year - 2002
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2002.1748
Subject(s) - environmental chemistry , mineralization (soil science) , chemistry , phosphorus , organic matter , hydrolysis , anoxic waters , wetland , surface water , environmental engineering , ecology , nitrogen , biology , biochemistry , environmental science , organic chemistry
Enzymatic hydrolysis and mineralization of organic phosphorus (P) were determined in surface water samples collected from inflow and outflow of a submerged aquatic vegetation (SAV)–dominated treatment wetland of the Florida Everglades. Water samples were fractionated into three size fractions (>0.4 μm, <0.4 to >0.05 μm, and <0.05 μm) with a sequential flow filtration technique. The fractionated water samples were incubated to hydrolyze with alkaline phosphatase (APase) and phosphodiesterase (PDEase), and to mineralize at different redox and pH. Unlike APase, which hydrolyzed ≤10% of organic P, PDEase hydrolyzed ≥71% of organic P in unfiltered water from both inflow and outflow waters, suggesting the domination of bioavailable diester P in the water. Phosphodiesterase completely hydrolyzed organic P in the <0.4‐ to >0.05‐μm and <0.05‐μm fractions, as compared with ≤35% in the >0.4‐μm fraction. However, the P mineralization in inflow and outflow waters at different redox and pH showed that P associated with particulate > 0.4 μm had been mineralized the most. Phosphorus‐31 nuclear magnetic resonance (NMR) spectroscopy showed that surficial sediments from the inflow region contained a high proportion of polynucleotides, nucleoside monophosphates, and previously unreported glycerophosphoethanolamine and phosphoenolpyruvates. However, at the outflow, the relative proportion of polynucleotides and nucleoside monophosphates was reduced substantially. This suggests that the SAV wetland may sequester P via accretion of organic matter.