Natural aquatic organic matter

Buffle, J., Tessier, A., and Haerdi, W., Interpretation of trace metal complexation by aquatic organic matter, in Complexation of Trace Metals in Natural Waters, Kramer, C.J.M. and Duinker, J.C., Eds., Martinus Nijhoff/Dr. W. Junk Publishers, The Hague, 1984, pp. 301-316. 

W.L. Miller (1994). Recent advances in the photochemistry of natural dissolved organic matter. In D. Crosby, G.R. Helz, R.G. Zepp (Eds), Aquatic and Surface Photochemistry (pp. 111-127). Lewis, Boca Raton. 

Releases of hydrogen sulfide to water occur both naturally and as a result of human activity. Hydrogen sulfide released from aquatic plants, or as a result of anaerobic chemical processes in swamps and bogs, may dissolve in the water column or bind to clay or organic matter. 

Ritter K, Aiken GR, Ranville JF, Bauer M, Macaladi DL (2006) Evidence for the aquatic binding of arsenate by natural organic matter suspended Fe(III). Environ Sci Technol 40 5380-5387... 

Humic acids (HA) and fulvic acids (FA) are the main components of humic substances (HS), which are the most chemically and biochemically active and widely spread fractions of nonliving natural organic matter in all terrestrial and aquatic environments. They comprise a chemically and physically heterogeneous group of substances with colloidal, polydis-persed, polyelectrolyte characteristics and mixed aliphatic and aromatic nature (Senesi and Loffredo 1999). 

The second difference between the laboratory tests and exposure under realistic environmental conditions is that in the laboratory exposure concentrations are maintained, or the ecotoxicological endpoints are adjusted to account for any decline. Under natural conditions a combination of the pyrethroids tendency to partition rapidly and extensively to organic matter, coupled with their susceptibility to degradation in aquatic systems where algae and macrophytes are present [13,14], means their overall dissipation rate from the water phase is generally relatively rapid. Water column dissipation half-lives tend to be around 1 day (see Sect. 5). This behavior means that it is unlikely that aquatic organisms will be exposed to pyrethroids in the water phase for prolonged periods in natural water bodies. 

Campbell, P. G. C., Twiss, M. R. and Wilkinson, K. J. (1997). Accumulation of natural organic matter on the surfaces of living cells implications for the interaction of toxic solutes with aquatic biota, Can. J. Fish. Aquat. Sci., 54, 2543-2554. 

Buffle, J. (1984). Natural organic matter and metal-organic interactions in aquatic systems. In Metal Ions in Biological Systems. Vol. 18, Circulation of Metals in the Environment, ed. Sigel, H., Marcel Dekker, New York, pp. 165-221. 

At present, soil derived humic matter and fulvic acids extracted from freshwater are available commercially and are commonly used to test techniques for DOM detection and also used as model compounds for trace metal chelation studies. The results obtained using these model compounds are frequently extrapolated to the natural environment and measurements on "real" samples provide evidence that this DOM is a good model compound. In the past, some investigators also made available organic matter isolated from marine environments using C18 resins. While these compounds come from aquatic sources, this isolation technique is chemically selective and isolates only a small percentage of oceanic DOM. Reference materials are not currently available for these compounds, which inhibits study of the role they play in a variety of oceanographic processes. 

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