1 How is elemental sulfur S0 oxidized by bacteria 2 Why woul

1) How is elemental sulfur (S₀) oxidized by bacteria?

2) Why would the strong smell associated with activated sludge disappear during the incubation process?

Solution

The elemental sulfur (SO) is oxidized by the bacteria is as follows:

1.) Mineralization of organic sulfur to inorganic sulfur such as hydrogen sulfide.

2.) Oxidation of hydrogen sulfide ( H₂S) and elemental sulfur (S) to sulfate (SO_4^2-).

3.) Reduction of sulfate to sulfide.

4. ) Incorporation of sulfide into organic compounds such as cyanobacteria and various fungi which absorb sulfur. This is often termed as :

Assimilative sulfate reduction in which sulfate (SO₄²) is reduced by plants, fungi and various prokaryotes.

Desulfurization in which organic molecules containing sulfur can be desulfurized, producing hydrogen sulfide gas.

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2.) The strong smell associated with activated sludge disappears gradually during the incubation phase as the sulfur and nitrogen based compounds from the it is slowly being consumed by the anaerobic bacteria for it\'s production of energy and by the time the incubation period is over the activated sludge is rid of it\'s strong odor.