Organic particulate matter

VACUUM RADIATING DESORPTION AND INFRARED SPECTROMETRY (VRDIR) FOR CONTINUOUS MONITORING OF SUSPENDED PARTICULATE ORGANIC MATTERS IN ATMOSPHERE... 

Essentially all the dissolved organic matter in seawater can be assumed to be non-living. However, particulate organic matter can be either living or dead, with the latter often referred to as "detritus."... 

Of the remaining particulate organic matter, very little is living (> 95% detritus). 

Eppley, R. W. and Peterson, B. J. (1979). Particulate organic matter flux and planktonic new production in the deep ocean. Nature 282, 677-680. 

Menzel, D. W. (1974). Primary productivity, dissolved and particulate organic matter and the sites of oxidation of organic matter. In The Sea," Vol. 5 (E. D. Goldberg, ed.). Wiley, New York. 

In addition to the interactions discussed above, which all depend in part on the ioniz-ability, or at least polarizability, of the surface and the adsorbates, hydrophobic parts of ligands may bind to corresponding parts of surfaces. Thus, if a metal ion is complexed or irreversibly bonded to a hydrophobic molecule, the metal may be incorporated into the bulk or surface of a particle via hydrophobic interaction between the molecule and the solid phase. Such interactions may be quantitatively significant in systems with high concentrations of dissolved and particulate organic matter. 

F g- 15-15 Schematic representation of Fe and organic matter interactions in an estuary. POM = particulate organic matter DOM = dissolved organic matter PIM = particulate inorganic matter. 

Transport in solution or aqueous suspension is the major mechanism for metal movement from the land to the oceans and ultimately to burial in ocean sediments. In solution, the hydrated metal ion and inorganic and organic complexes can all account for major portions of the total metal load. Relatively pure metal ores exist in many places, and metals from these ores may enter an aquatic system as a result of weathering. For most metals a more common sequence is for a small amount of the ore to dissolve, for the metal ions to adsorb onto other particulate matter suspended in flowing water, and for the metal to be carried as part of the particulate load of a stream in this fashion. The very insoluble oxides of Fe, Si, and A1 (including clays), and particulate organic matter, are the most important solid adsorbents on which metals are "carried."... 

This has led to research into identification of labile pools of organic matter (which make up a relatively small proportion of the total pool) that are more sensitive to changes in soil management or environmental conditions than total soil organic matter content. Examples of such pools include C and N held in the microbial biomass and in particulate organic matter and in water-soluble, easily-extractable and potentially mineralizable fractions (Haynes 2005). 

Particulate organic matter is transitoiy pool between fresh plant residues and humified organic matter (Gregorich and Janzen 1996). Often the term light fraction is used as a synonym for POM (von Lutzow et al. 2007). While POM and LF are similar, they are not equivalent fraction and have different C-, N-, O-alkyl contents (Gregorich et al. 2006). 

Particulate organic matter LF — 2-18% of organic C, 1-16% of total N SSF - 20 45% of organic C and 13-40% of total N Partially decomposed plant litter isolated by density fractionation (LF) or sieving (SSF). Substrate and centre for soil microbial activity, short-term reservoir of nutrients, food source for earthworms and other soil fauna and focci for formation of water stable aggregates. 

Bongiovanni MD, Lobartini JC (2006) Particulate organic matter, carbohydrate, humic acid contents in soil macro- and microaggregates as affected by cultivation. Geoderma 136 660-665... 

Denef K, Six J, Bossuyt H, Frey SD, Elliott ET, Merckx R, Paustian K (2001) Influence of dry-wet cycles on the interrelationship between aggregate, particulate organic matter, and microbial community dynamics. Soil Biol Biochem 33 1599-1611... 

Kolbl A, Kogel-Knabner I (2004) Content and composition of free and occuluded particulate organic matter in a differently textured arable Cambisol as revealed by solid-state 13C NMR spectroscopy. J Plant Nutr Soil Sci 167 45-53... 

Kolbl A, Leifeld J, Kogel-Knabner I (2005) A comparison of two methods for the isolation of free and occluded particulate organic matter. J Plant Nutr Soil Sci 168 660-667... 

McCarthy, J.F. (1983) Role of particulate organic matter in decreasing accumulation of polynuclear aromatic hydrocarbons by Daphnia magna. Arch. Environ. Contam. Toxicol. 12, 559-568. 

The highest concentrations of naturally occurring dissolved and particulate organic matter in the oceans are normally found in the surface films. When organic pollutants are present, they too, tend to accumulate in this surface film, particularly if they are either non-polar or surface active. Much of the available information on these surface films is reviewed by Wangersky [8,9]. 

Seymour MP (1977) The biodegradation of particulate organic matter in saltwater media. Dissertation, Rice University... 

The half-time persistence of 1,3,6,8-TCDD and OCDD in freshwater is short, of the order of 2.6 to 4 days the rapid partitioning to dissolved and particulate organic matter in the water column and sediments limited their bioavailability (Servos et al. 1992a). Techniques are now available to... 

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