Observation table of bacterial contamination in drinking water by testing sulphide ions
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Answer:
Under acidic conditions, the concentration of hydrogen sulphide predominates. Hydrogen sulphide is a weak acid, which ionizes to yield hydrosulphide (HS_-) and sulphide (S2) ions. Hydrogen sulphide is extremely toxic to fish. Concentrations of total sulphide as low as 0.01 mg/L make the water unfit for uninhibited fish culture. Hydrogen sulphide also reduces the aesthetics value of the water body due to foul color. The bacterial contamination can be tested using H2S strip .
The water to be tested is to be filled in the bottle having H2S strip, and keep it in the incubator ;at 35degree centigrade for 14 to 16 hours. If the strip becomes black then the water is not fit for human consumption as it is contaminated and bacteriologically not potable. This is the simple and quick method as it needs no sterilization.