Table 1: Main functional groups of DOC, which create complexation binding with Hg and participate in oxidation-reduction reactions.

Binding siteFunctional groupProducts

Oxygen (O)fig.006CO2
–CH2–OH–HC=O

Nitrogen (N)–CH2–NH2NH3 + –CH3
–CH2–NH–CH2
fig.007

Sulphur (S)–CH2–SH–CH2–S–S–CH2
–CH2–S–CH2