Aquatic particles

Buesseler KO, Bauer JE, Chen RF, Eglinton TI, Gustafsson O, Landing W, Mopper K, Moran SB, Santschi PH, Vernon Clark R, Wells ML (1996) An intercomparison of cross-flow filtration techniques used for sampling marine colloids overview and organic carbon results. Marine Chem 55 1-31 Buffle J, Perret D, Newman M (1992) The use of filtration and ultrafiltration for size fractionation of aquatic particles, colloids, and macromolecules. In Enviroiunental particles. Buffle J, van Leeuwen HP (eds) Lewis Publishers, Boca Raton FL, pl71-230... 

Figure 1. Schematic of an FFF channel with the separation mechanism for normal FFF shown in detail. Reprinted from [7] Beckett, R. and Hart, B. T. Use of field flow fractionation techniques to characterize aquatic particles, colloids and macromolecules . In Environmental Particles. Vol. 2, IUPAC Series on Analytical and Physical Chemistry of Environmental Systems. Series eds. Buffle, J. and van Leeuwen, H. P., pp. 165-205. Copyright 1993 IUPAC. Reproduced with permission...

Binding of Reactive Elements to Aquatic Particles in Natural Systems... 

Although aquatic particles bear electric charge, this charge is balanced by the charges in the diffuse swarm which move about freely in solution while remaining near enough to colloid surfaces to create the effective (counter) charge gd that balances gp... 

Buffle, J., D. Perret and M. Newman (1992), The use of Filtration and Ultrafiltration for Size Fractionation of Aquatic Particles, Colloids and Macromolecules", in J. Buffle and H.P. v. Leeuwen, Eds., IUPAC Series in Environmental Physical and Analytical Chemistry, Lewis Publ., Chelsea, Ml. 

Gustafsson, O., Bucheli, T.D., Kukulska, Z., Andersson, M., Largeau, C., Rouzaud, J.N., Reddy, C.M., and Eglinton, T.I. (2001) Evaluation of aprotocol for the quantification of black carbon in sediments, soils and aquatic particles. Global Biogeochem. Cycles 15, 881-890. 

The experiment described, in which the dominant electrolyte ion is switched, is basically the method used to measure the exchange characteristics of a particular soil, sediment, or aquatic particle. Batch techniques are used most commonly, but ion exchange is also sometimes measured via experiments involving continuous flow through packed columns (16, 17). In both techniques, changes in the aqueous and/or solid-phase concentrations of the competing ions are measured to provide information about ion uptake or release by the solid phase. 

The peroxides that activate these enzymes are produced internally by th biota or, alternatively, are produced externally, mainly by photochemical proc esses in the sea (72). Gschwend et al. (71), having found very little halocarboi in the interior tissues of macroalgae that produce these compounds, conclude" that much of the activity must be located in the surface tissues. This findin is consistent with the idea that extracellular peroxides are involved in th activation of these haloperoxidases. Moffett and Zafiriou (73) and Cooper am Zepp (74) provided evidence that peroxidases associated with aquatic particle in fresh water and coastal waters account for a large fraction of the decay o hydrogen peroxide, although it was not shown that haloperoxidases were re sponsible for the observed activity. 

Isobe, T., H. Nishiyama, A. Nakashima and H. Takada. Distribution and behaviour of nonylphenol, octylphenol, and nonylphenol monoethoxylate in Tokyo metropolitan area their association with aquatic particles and sedimentary distributions. Environ. Sci. Technol. 35 1041-1049, 2001. 

S. Tassan, G.M. Ferrari, A. Bricaud, M. Babin (2000). Variability of the amplification factor of light absorption by filter-retained aquatic particles in the coastal environment. J. Plankton. Res., 22, 659-668. 

Short-lived isotopes of Pb such as Pb (ti/2 = 22.26 year), Pb (tj/2 = 10.6 h), " Pb (ti/2 = 26.8 min) are useful tracers of transient signals for studying sediment fluxes in estuaries [62], deposition of atmospheric particles [63,64], scavenging of trace metals by aquatic particles [65], and oceanic circulation [66]. Lead-210 in particular, has been extensively used as a geochronological tool for studying the accumulation rates of sediments, peat, and glacial ice during the past two centuries [67,68]. 

Another important feature of radiocesium partitioning in sediments is its apparently irreversible behaviour. It has generally been observed that Kd increases, and the exchangeability of radiocesium bound to aquatic particles decreases, with increasing contact time between the radionuclide and the particles (e.g. 1,2 J3). This observation has been interpreted as a slow migration of radiocesium from the frayed edge sites towards the deeper interlayer spaces between the illite layers, from where it cannot easily be released (3,14). It is, therefore, important to obtain rate parameters for this process in order to enable prediction of the long-term availability of radiocesium to the aqueous phase, and thus for further transport and uptake in the aquatic food chain. 

NATUREAND MORPHOLOGY OF AQUATIC PARTICLES/COLLOIDS USE OF FRACTAL CONCEPTS... 

Beckett R and Hart BT (1993p) Use of field-flow fractionation techniques to characterize aquatic particles, colloids and macromolecules. In Buffle J and van Leeuwen HP (eds.) Environmental Particles, vol. 2, pp. 165-205. Boca Raton, FL Lewis. 

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