Rhine River particle

Figure 8.6 Size distributions (particles below lpm) based on particle number for different natural water systems Gulf of Mexico (Harris, 1977), foraminifera and diatoms from near-surface South-lndian Ocean (Lai and Lerman, 1975), coastal surface waters of North Pacific Ocean (off Tokyo Bay) (Koike et al., 1990), Grimsel test site groundwater (Switzerland) (Degueldre, 1990), Markham Clinton groundwater (UK) (Longworth et al., 1990), amorphous iron oxy(hydroxo)phos-phate at the oxic/anoxic boundary of Lake Bret (Switzerland) (Buffle et al., 1989), Rhine River (The Netherlands) (van de Meentef al., 1983), Rhine River (Basle, Switzerland) (Newman etal., 1994), St Lawrence River (Canada) (Comba and Kaiser, 1990). Distributions recalculated from the original data as explained in Filella and Buffle (1993) (reproduced from Filella and Buffle, 1993, by permission of the copyright holders, Elsevier Science Publishers BV, Amsterdam).

Newman, M.E., Filella, M., Chen, Y., Negre, J.-C., Perret, D. and Buffle, J. (1994) Submicron particles in the Rhine River - II. Comparison of field observations and model predictions. Water Res., 28, 108-118. 

Some of the DNOC sticks to particles present in water. This process partially transfers DNOC from water to the bottom sediment. When DNOC was accidentally spilled into the Rhine River in Germany, the level of DNOC in water decreased to half its initial value in an estimated 30 days. No known chemical reaction removes significant amounts of DNOC from soil. Microorganisms break down DNOC in soil. The loss of DNOC from soil by evaporation is not significant. DNOC has been found in groundwater from fields where it was applied. The level of DNOC in soil may decrease to half its original level in an estimated 14 days to I month or longer. You will find further information about the fate and movement of DNOC in the environment in Chapter 5. 

Perret, D. et al., Submicron particles in the Rhine River-1 Physico-chemical characterization, Water Res., 28, 91, 1994. 

Colloids can be organic or inorganic. Even if they are not separated from the dissolved load by classical filtration, colloids have the physicochemical properties of a solid. Colloids are finely divided amorphous substances or sohds with very high specific surface areas and strong adsorption capacities. It is shown by Ferret et al. (1994) for the Rhine River that the colloids contribute less than 2% of the total particle volume and mass, but represent a dominant proportion of the available surface area for adsorption of pollutants. The abundance of colloids, their fate, through coagulation and sedimentation processes in natural waters therefore control the abundance of a number of elements. 

The material was collected in the Rhine River, air-dried and further dried at 40 C for 48 h. About 40 kg were milled, homogenised and sieved to obtain particles of less than 250 pm size. The treatment was carried out following the Dutch norm NEN 5751. The material was bottled in brown glass bottles (1200 bottles each containing ca. 30 g). 

Differentiation of sedimentary metal phases was performed on grain size fractionated samples from the lower Rhine River by successive chemical leaching (review). Pollution affects the significant increase of nonresidual associations of chromium, cop er, lead, and zinc. Except for manganese the metal contents in most of the extracted phases decrease as the grain size increases. Phase concentration factors (PCF relative enrichment of metal content in major carrier substances) are high for chromium in moderately reducible phases (20-fold increase in clay-sized particles), for manganese and zinc in the easily reducible sediment fraction (30- and 55-fold enrichment), and for copper and zinc in the carbonates (15 or 25 times compared with total sediment). 

Enrichment (or Reduction) of Metal Concentrations in Major Sediment Particles from the Rhine River ... 

Ferret D., Newman M.E., Negre J.-C., Chen Y., Buffle J. (1994), Submicron particles in the Rhine River-I. physico-chemical characterisation. Water Research, 28, 1, 91-106. 

Comparison of Tables 6.2.4 and 6.2.6 shows that dissolved concentrations of NP and NPEO are higher in the Rhine and Meuse rivers than in the Hessian river, which is probably caused by accumulation from diffuse and point sources along the rivers. On the contrary, levels of NPEC in Hessian streams are similar to those observed in the rivers Rhine and Meuse in The Netherlands. An explanation for this could be that degradation occurs relatively more readily in the smaller streams due to slower water velocities and a lower particle density in these waters. 

Van de Meent, D., Los, A., Leeuw, J.W., Schenck, PA. and Haverkamp, J. (1983) Size fractionation and analytical pyrolysis of suspended particles from the River Rhine Delta. In Advances in Organic Geochemistry, 1981 (eds Bjoroy, M. et al.). Wiley, Chichester, pp. 336-349. 

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