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CH3041
THE SULPHUR CYCLE
II
• The largest reservoir in the S cycle is the
crust with only a small atmospheric storage.
The ocean reservoir is also large.
crust with only a small atmospheric storage.
The ocean reservoir is also large.
• H2S
(S) SO2 SO3 SO42-
These are the major forms of sulphur which
are cycled by microbial organisms.
These are the major forms of sulphur which
are cycled by microbial organisms.
• Atmospheric SO2 is oxidised to H2SO4 (»60%)
SO2 + ½O2 Mn(II) ® SO3
SO3 +2H2O ® H2SO4 + H2O
• Many other processes also result in the
oxidation of SO2 to H2SO4 . Removal also
occurs by dry deposition.
oxidation of SO2 to H2SO4 . Removal also
occurs by dry deposition.
• The average lifetime of the SO2 mixture is
2 - 6 days during which it travels < 4000km.
2 - 6 days during which it travels < 4000km.
