Identification of organic phosphorus compounds in the Bronx River bed sediments by phosphorus-31 nuclear magnetic resonance spectroscopy

Sediment characteristics influence the distribution and bioavailability of phosphorus (P) in rivers and lakes. The objectives of this study were to identify P compounds in sediments collected from 15 sites along the Bronx River to get insights on nutrient transport for management of highly variable and modified ecosystems such as the Bronx River. The nuclear magnetic resonance spectra showed that the dominant P species in Bronx River bed sediments are orthophosphate monoester and lesser phosphate diesters and pyrophosphates (pyro-P). The P compounds were mostly glycerophosphate, nucleoside monophosphates, and polynucleotides. A few sites showed a small amount of dihydroxyacetone phosphate, inosine monophosphate. By allowing a downstream comparison of P compound variations along the Bronx River, this study provides a step toward improving water quality in an urban river system such as New York City and helps to assess the bioavailability of P, in turn, design estuary habitat restoration projects in comparable region of the world.