Question

what is waste water becomes black in colour? because of what chemical it becomes black? ​

Answer 1

Answer:

Hi.........mm.m

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Answer 2

Answer:

The colour of stale sewage is observed to be dark brown or black which indicates that the dissolved oxygen content is very low and the biological decomposition process is slow. Anaerobic decomposition starts after the colour of the sewage turns black as the dissolved oxygen content reaches minimum value.

Oxidized forms of manganese usually remain dissolved in water, giving it a black tint. These abrupt changes in the chemical forms of iron and manganese are responsible for the staining properties of aquifer waters containing high concentrations of these elements.

Explanation:

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