An Introduction to Environmental Chemistry

H 2 SO 4 makes drainage from abandoned mines strongly acidic (pH as low as 1 or
2). This acidity increases the solubility of aluminium and other metals, causing
toxicity in aquatic ecosystems. Microorganisms are closely involved in sulphide
oxidation, which can be modelled by a series of reactions:

The Chemistry of Continental Waters 157

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North

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10

10

50

25

50

25

Atlantic

Ocean

Baltic

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km

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N

(a)

Fig. 5.7Rates of acid deposition (contours of mmol H+l-^1 ) and areas most sensitive to
acidification (shaded) based on their rock type: (a) Europe, (b) North America. Modified from
Likens et al. (1979), with kind permission of A.M. Tomko III.