Water particulate organic matter

Francois R, Altabet MA, Goericke R, McCorkle DC, Brunet C, Poisson A (1993) Changes in the d C surface water particulate organic matter across the subtropical convergence in the S.W. Indian Ocean. Glob Biogeochem Cycle 7 627-644... 

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 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. 

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... 

Wakeham, S.G., and C. Lee. 1993. Production, transport, and alteration of particulate organic matter in the marine water column. Pp. 145-169 in Organic Geochemistry Principles and Applications, M.H. Engle and S.A. Macko, eds., New York Plenum Press. 

Vertical segregation The vertical gradient in biogenic materials, such as nutrients and O2, that is established by the interaction between the biogeochemical cycling of particulate organic matter and the vertical density stratification of the water column. Strongest at mid and low latitudes. 

Multivariate source. apportionment models have been developed for two fractions of respirable particulate organic matter which together constitute about 90% of the total organic solvent-extractable mass. The independent variables used for developing the models were trace metals, water-soluble sulfate and meteorological variables. Two of the three POM fractions extracted sequentially with cyclohexane (CYC), dlchloromethane (DCM) and acetone (ACE) were used as individual dependent variables. 

Table 9.2 LFERs Relating Particulate Organic Matter-Water Partition Coefficients and Octanol-Water Partition Constants at 20 to 25°C for Some Sets of Neutral Organic Compounds Slopes and Intercepts of Eq. 9-25a... 

Numerous studies have been conducted on the nature of the dissolved and particulate organic matter in natural waters. In general, these studies have shown that the composition of the bulk of the organic matter is undefined. Many of the laboratory studies on the nature of the dissolved organic matter in natural waters are of limited value owing to possible alteration of the compounds by the concentration and analytical methods used. The selectivity of the methods used to concentrate the solute to analytically detectable levels presents another problem in many analytical procedures used to study trace compounds in natural waters. Concentration procedures such as freezing, flocculation, sorption columns, and solvent extraction, have been shown to be selective for certain types of compounds (32, 34, 38). Extreme care must be exercised to insure... 

Newell, R.C. and Lucas, M.I., 1981. The quantitative significance of dissolved and particulate organic matter released during fragmentation of kelp in coastal waters. Kieler Meeresforsch., 5 356-369. 

E. Batoosingh, G.A. Riley and B. Keshwar, An analysis of experimental methods for producing particulate organic matter in sea water by bubbling, Deep-Sea Res. 16 (1969) 213-219. 

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