An Introduction to Environmental Chemistry

tions stood at 47 g l-^1. Rivers draining into the Salton Sea have a Na+/Ca^2 + ratio of about 5 : 1 (on an atomic basis) but as ...

eqn. 5.8 the dissociation constant is, eqn. 5.9 It is simple to demonstrate that the alkalinity in most continental waters is do ...

The Chemistry of Continental Waters 153 pH 0 0.5 1 1.5 2 2.5 3 Alkalinity (meq l–1) 0 2 4 6 8 10 Ca 2+ (mmol l –1 ) Ca2+ pH 1.0 ...

154 Chapter Five Box 5.3 Worked examples of pH buffering The principle of pH buffering can be illustrated by considering the sim ...

and alkalinity is, in this example, approximately linear, although for every mmol of Ca^2 +, 2 mmol of HCO 3 - are released, as ...

5.4.1 Acidification from atmospheric inputs Acidification of soilwater occurs if the rate of displacement of soil cations by H+ ...

H 2 SO 4 makes drainage from abandoned mines strongly acidic (pH as low as 1 or 2). This acidity increases the solubility of alu ...

eqn. 5.15 followed by the oxidation of ferrous iron (Fe(II)) to ferric iron (Fe(III)): eqn. 5.16 Oxidation happens very slowly a ...

eqn. 5.17 At pH values much above 3 the iron(III) precipitates as the common iron(III) oxide, goethite (FeOOH): eqn. 5.18 The pr ...

The Onyx River in Antarctica plots in the top corner of Fig. 5.8 as a pure chloride (sea-salt-dominated) system. As this river e ...

weathering of evaporite minerals (NaCl and CaSO 4 ) in the catchment, and the concentration of dissolved salts by evaporation, l ...

process is illustrated in Fig. 5.9 using data from Esthwaite, a lake in northwest England. In March the water column is well mix ...

The Chemistry of Continental Waters 163 same redox potential as nitrate reduction), these oxides may be reduced to soluble Fe(II ...

164 Chapter Five Box 5.4 Eh-pH diagrams Acidity (pH) and redox potential (Eh) (see Box 4.3) may determine the chemical behaviour ...

The Chemistry of Continental Waters 165 the existence of water. Under very oxidizing conditions (Eh 0.6 to 1.2 V) water is broke ...

controlled to limit algal growth in the receiving waters, even though the need for this strategy arises from nitrate enrichment. ...

ammonium (NH 4 +) and N(5+) nitrate (NO 3 - ) are the most important. Nitrogen gas dissolved in natural waters cannot be utilize ...

and animal wastes, will wash out of soils and into rivers. The seasonal variation of NO 3 - concentrations in many temperate riv ...

Phosphorus and nitrogen in groundwater The very different chemistry of DIP and NO 3 - is illustrated by their behaviour in groun ...

increases in nitrate inputs) has resulted in large-scale changes in phytoplankton ecology in the Black Sea itself. Large numbers ...