River water chemistry

River water chemistry is determined by the relative concentrations of major dissolved components (bicarbonate, calcium ion, silica, and sulfate), which are in turn controlled by the environment. Rivers in precipitation-dominated... 

This chapter describes the main physical characteristics of the Ebro River, including the watershed orography, the biogeography and vegetation, the climatic and hydrological characteristics, and the soil type and biogeochemistry of river Ebro waters. The Ebro watershed has historically served as nucleus and connection for humans human settlements are known since pre-historic years and nowadays the river water chemistry cannot be understood without the anthropogenic effects. Therefore, the potential effects of human activities at the Ebro watershed are analyzed. 

Recently, detailed studies on the factors controlling river water chemistry such as biological activity (Likens et al. 1987), soilwater (Holland 1978 Likens et al. 1987) and geography (Drever 1988) have been done. However, the chemical compositions of major river water plot in chemical weathering-dominated region. 

Therefore, the relationship between chemical weathering and river water chemistry is considered below. 

Gaillardet et al. (1999) estimated contribution of chemical weathering to river water chemistry based on Sr isotopic composition, concentration ratio of elements to Na, and runoff. According to their works, contributions of chemical weathering for Si and K are 100 % and 60 %, respectively. Those for Na, Ca, HCOa" and Sr are less than 50 %. It is obtained that the contribution of Si is the highest. Therefore, Si concentration of river water is considered below. 

Hur J, Schlautman MA, Karanfil T, Smink J, Song H, Klaine SJ, Hayes JC (2007) Influence of drought and municipal sewage effluents on the baseflow water chemistry of an upper Piedmont River. Environ Monit Assess 132 171-187... 

Dickinson et al. also used microelectrodes to measure dissolved oxygen (DO), H2O2, and local within biofouling deposits on stainless steel surfaces exposed to river water to further resolve the interfacial chemistry that resulted in ennoblement. Data were then compared with those from similar measurements as close as possible to the environment of a non-fouled substratum. 

River runoff and i situ production are the major sources of U-Th series nuclides (Table 1) to the oceans. The concentrations of the various U-Th series nuclides in rivers vary considerably and depend upon several factors prime among them being their chemical reactivity [13], the chemistry of river water, and the nature of the river bed. 

Fig. 5.18 illustrates the difference in water chemistry of rivers draining CaC03 (cal-cite) or crystalline rocks. 

The overall effect of the terrestrial weathering reactions has been the addition of the major ions, DSi, and alkalinity to river water and the removal of O2, and CO2 from the atmosphere. Because the major ions are present in high concentrations in crustal rocks and are relatively soluble, they have become the most abimdant solutes in seawater. Mass-wise, the annual flux of solids from river runoff (1.55 x 10 g/y) in the pre-Anthropocene was about three times greater than that of the solutes (0.42 x 10 g/y). The aeolian dust flux (0.045 X 10 g/y) to the ocean is about 30 times less than the river solids input. Although most of the riverine solids are deposited on the continental margin, their input has a significant impact on seawater chemistry because most of these particles are clay minerals that have cations adsorbed to their surfaces. Some of these cations are desorbed... 

The other reason why the average salinity of seawater is 35%o lies in the fundamental chemistry of major ions. For example, the sevenfold increase in the Na /K ratio between river water and seawater (Table 21.8) reflects the lower affinity of marine rocks for sodium as compared to potassium. In other words, the sodium sink is not as effective as the one for potassium. Thus, more sodium remains in seawater, with its upper limit, in theory, being controlled by the solubility of halite. Likewise, the Ca /Mg ° ratio in seawater is 12-fold lower than that of river water due to the highly effective removal of calcium through the formation of biogenic calcite. 

Zobrist J (2010) Water Chemistry of Swiss Alpine Rivers. In Bundi U (ed.) Alpine Waters. Handbook of Environmental Chemistry, vol. 6. Springer, Heidelberg... 

Any relationships between salinity and arsenic chemistry in estuary waters often vary with location and climate. In some areas, periodic upwelling of high-arsenic and saline bottom waters locally dominates the arsenic chemistry of estuaries (e.g. the Taiwan Strait (Xiankun, Jing and Xinian, 1994), 332). In other situations, wet season flooding of highly arsenic-contaminated river waters increases the arsenic contents and lowers the salinity of estuaries. In contrast, fairly pristine river waters may dilute both estuary salinity and arsenic concentrations during flooding. 

The arsenic chemistry of the Krka estuary, Croatia, is very pristine that is, essentially unaffected by arsenic pollution from humans. Total dissolved arsenic concentrations in the estuary waters vary from 0.13 to 1.8 pgL-1 (Table 3.7 (Smedley and Kinniburgh, 2002), 525). The range of concentrations can be readily explained by low-arsenic (0.13 pg E1) river water simply diluting 1.8 pgL-1-arsenic seawater in various proportions (Smedley and Kinniburgh, 2002), (Seyler and Martin, 1991), 525. In this estuary, arsenic (in particular As(V)) behaves conservatively that is, the element is relatively unreactive in at least the short... 

Meek, M., Love, D. and Mapani, B. (2006) Zimbabwean mine dumps and their impacts on river water quality -a reconnaissance study. Physics and Chemistry of the Earth, 31(15-16), 797-803. 

Veith G (1968) Environmental chemistry of the chlorobiphenyls in the Milwaukee River. PhD Dissertation, Water Chemistry Program, University of Wisconsin, Madison, Wisconsin... 

Our observations are similar to those of Blanck et al. (2003), who studied the variability in zinc tolerance in periphyton communities sampled from 15 European river stretches using the PICT concept. Due to differences in water chemistry, (history of) metal pollution, species composition, and other biotope characteristics, the regional uncertainty factor for Zn was estimated to range from 1.7 to 4.3, and the interregional uncertainty factor from 2.4 to 8.6, when extrapolating periphyton tolerances from river to river (Blanck et al. 2003). 

Schaller H, Neeb R. 1987. Gas-chromatographic elemental analysis via di(trifluoroethyl)dithiocarbamato-3 chelates X. Capillary gas chromatography at the pg-level determination of Co and Cr[VI] besides Cr[III] in river water. Fresenius Z Analytical Chemistry 327 170-174. 

Suspended solids have the potential to silt out stream channels, rivers, lakes, and reservoirs they inhibit aquatic life and are expensive to remove from water. In some industries (e.g., mining) suspended solids, along with various other pollutants, are regulated by law, which requires that sediment ponds at the base of disturbed watersheds be built with sufficient detention time so that the water released meets certain sediment and water chemistry criteria (Tables 9.1 and 9.2). 

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