Particulate organic phosphorus

Benitez-Nelson, C. R., O Neill, L., Kolowith, L. C., Pellechia, P. J., and Thunell, R. C. (2004). Phosphonates and particulate organic phosphorus cycling in an anoxic marine basin. Limnol. Oceanogr. 49,1593-1604. 

DOP, DON, and DOC represent dissolved organic phosphorus, nitrogen, and carbon, respectively. POP, PON, and POC represent particulate organic phosphorus, nitrogen, and carbon, respectively, ud = undetectable. 

Suzumura, M. and Ingall, E.D. (2001) Concentrations of lipid phosphorus and its abundance in dissolved and particulate organic phosphorus in coastal seawater. Marine Chemistry 75, 141-149. 

Growth of chemolithotrophic bacteria, such as nitrifiers, sulphide-oxidizers and methane-oxidizers, is an alternative means of primary production for the conversion of phosphate to particulate organic phosphorus. These bacteria may act as scavengers for phosphorus transported from the deep water... 

Phosphorus is transported through wetlands in soluble and particulate forms, including dissolved inorganic phosphorus (DIP), particulate inorganic phosphorus (PIP), dissolved organic phosphorus (DOP), and particulate organic phosphorus (POP). 

Algae and bacteria are known to release extracellular alkaline phosphatase, which facilitates utilization of otherwise unavailable dissolved and particulate organic phosphorus species. This behavior has been used as the basis for a speciation technique aimed at estimating BAP in the dissolved fraction. Alkaline phosphatase has been used in soluble and immobilized forms to hydrolyze FOP in natural waters, and the resultant orthophosphate is detected as FRP. Use of the soluble enzyme technique has essentially been discarded because of product inhibition of the alkaline phosphatase by orthophosphate aheady present... 

Combustion methods have been used to determine total sulphur and total organic carbon and total halides in soil, total and particulate organic carbon, total halide, phosphorus and nitrogen, total and particulate organic carbon in saline sediments and total nitrogen in sludges. 

Bloesch, J., and M. Sturm, Settling flux and sinking velocities of particulate phosphorus (PP) and particulate organic carbon (POC) in Lake Zug, Switzerland . In Sediments and Water Interactions, P. G. Sly, Ed., Springer, New York, 1986, pp. 481-490. 

For these reasons, numerous attempts have been made to identify and characterize DOP, but with little success because it is usually present in very low concentrations. Typical values in lake waters range from 5 to 100 xg of P/L in oligotrophic to eutrophic systems. Colorimetric methods have been used extensively to detect and differentiate between soluble reactive phosphorus (SRP) and soluble unreactive phosphorus (SUP) at concentrations as low as 10 xg of P/L (I). SRP is generally considered to consist of only orthophosphate compounds, whereas SUP is composed of all other phosphorus species, primarily organic phosphorus compounds. The sum of SRP and SUP is equal to the total soluble phosphorus (TSP). These methods were used to study the dynamics of bulk phosphorus fractionation between the sediments, suspended particulate matter, the biota, and the dissolved fraction (2). Despite these studies, very little is known regarding the identity and characteristics of the DOP in the hydrosphere. 

Figure 9.22. Oceanic cycles of organic carbon, nitrogen, and phosphorus. DOC = dissolved organic carbon POC = particulate organic carbon NPP = net primary production DN = dissolved nitrogen PN = particulate nitrogen DP = dissolved phosphorus, PP = particulate phosphorus. C and N fluxes are in units of 1012 moles C and N y1 P fluxes are in units of 1010 moles P y1.

The cycling and availability of P in estuaries is largely dependent on P specia-tion. Consequently, total P has traditionally been divided into total dissolved P and total particulate P fractions, which can be further divided into dissolved and particulate organic P and dissolved and particulate inorganic P pools. Another defined fraction within the TP pool is reactive phosphorus, which has been used to describe the potentially bioavailable P. Much of the work to date has focused on the soluble reactive P, which is characterized as the P fraction that forms a phosphomolybdate complex under acidic conditions. 

Fig. 5 Vertical distribution of temperature (T), salinity (S), dissolved oxygen (O2), dissolved manganese (Mn diss), particulate manganese (Mn part), bivalent iron (Fe(II)), trivalent iron (Fe(III)), phosphate (P04), manganese complex (Mn com), organic phosphorus (Porg), and polyphosphate (Ppoly) at a station near Gelendzhik (St. 2618, September, 2006). Concentrations of chemical parameters are in xM. Distributions are plotted versus depth (m) at the top and versus density (og, kgm-3) at the bottom...

Figure 15.7 Fine (< 65 ]im) and coarse (> 65 pm) particulate organic carbon (POC, top), particulate organic nitrogen (PON, middle), and particulate phosphorus (PP, bottom) versus their respective fine or coarse sediment concentration. The symbol key in the lower panel applies to the entire figure.

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