Total particulate phosphorus

Figure 14. Isopleths of total particulate phosphorus concentration (milligrams/ gram) in the <8.2-pm size fraction of the suspended particulate material.

Figure 15.6 Downstream distributions of total particulate phosphorus (PP) between Vargem Grande and 6bidos in the Brazilian Amazon. Distributions are given for both rising- and falling-water periods. Solid dashed and thick gray lines are as defined in Fig. 15.4. All concentrations are pM.

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. 

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 10. Phosphorus settling rates in 1982, calculated as the sediment-trap-measured depositional flux divided by the total particulate P concentration...

Solorzano, L., and Sharp, J. H. (1980b). Determination of total dissolved phosphorus and particulate phosphorus in natural waters. Limnol. Oceanogr. 25,754-758. 

Figure 11.7 Total particulate phase content of phosphorus [e.g., labile, Fe-P, organic P (Org-P), calcium phosphate (Ca-P), and detrital phosphorus (Detr-p)] in total suspended solids (TSS) (pg g-1 dry wt. TSS) in waters of the lower Mississippi River and inner Louisiana shelf, versus seasonal variability and increasing salinity. (Modified from Sutula et al 2004.)...

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. 

Howarth et al. (1995) also estimate the total flux of riverine particulate phosphorus to the oceans at 0.23x10 moles P yr , an estimate likely too low because it uses the suspended sediment flux from MilUman and... 

This method is used for the determination of total chromium (Cr), cadmium (Cd), arsenic (As), nickel (Ni), manganese (Mn), beiylhum (Be), copper (Cu), zinc (Zn), lead (Pb), selenium (Se), phosphorus (P), thalhum (Tl), silver (Ag), antimony (Sb), barium (Ba), and mer-cuiy (Hg) stack emissions from stationaiy sources. This method may also be used for the determination of particulate emissions fohowing the procedures and precautions described. However, modifications to the sample recoveiy and analysis procedures described in the method for the purpose of determining particulate emissions may potentially impacl the front-half mercury determination. 

Fig. 3-2. I assume that 95 percent of the phosphorus supplied to the surface sea is incorporated into organic matter and returned to the deep sea in particulate form. One percent of the total survives to be buried in sediments. The rest is restored to the deep sea as dissolved phosphorus. The loss to sediments is balanced for the whole ocean by supply by the rivers. The fluxes here are in relative units.

It is seen by examination of Table 1.11(b) that a wide variety of techniques have been employed including spectrophotometry (four determinants), combustion and wet digestion methods and inductively coupled plasma atomic emission spectrometry (three determinants each), atomic absorption spectrometry, potentiometric methods, molecular absorption spectrometry and gas chromatography (two determinants each), and flow-injection analysis and neutron activation analysis (one determinant each). Between them these techniques are capable of determining boron, halogens, total and particulate carbon, nitrogen, phosphorus, sulphur, silicon, selenium, arsenic antimony and bismuth in soils. 

Figure 8.2 Regression of total (dissolved and particulate) nitrogen and phosphorus from estuaries, surface films, and oceanic surface (< 50 m) and deep waters. (Modified from Downing, 1997.)...

The variation in total available sediment phosphorus concentration among the three sediment types shown in Table II is clear. A statistical analysis of this data shows that both the suspended sediment and particulate total phosphorus concentrations are greater than the bottom sediment value at the 99% confidence level. Phosphorus content increases in the sequence bottom sediment, suspended sediment, and particulate material in accordance with the increase in surface area (M. M. Reddy, New York State Dept, of Health, unpublished data, 1977). High surface area sediment components may adsorb phosphorus-containing substances,from the water column, increasing their phosphorus concentration. Another possible explanation includes dilution of bottom sediment by relatively inert primary minerals in the sand and silt size fractions. 

Typical results for Genesee River watershed bottom sediment phosphorus contents are (phosphorus analysis, x (ug/g), (ug/g), h) total phosphorus, 560, 140, 99 NaOH extractable phosphorus, 58, 62, 98 HCl extractable phosphorus, 398, 99, 98 NH20H extractable phosphorus, 74, 63, 98 (NH )2C204 extractable phosphorus 184, 93, 83. Bottom sediment, suspended sediment, and particulate total phosphorus (560 ug/g, 770 ug/g, and 910 ug/g respectively) Increase as does specific surface area, across these fractions indicating that adsorption processes may be important in increasing sediment phosphorus concentrations. 

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