A. Reduction in its dissolved oxygen content
B. Discoloration of bathroom fixtures
C. Temporary hardness
D. None of these
Related Mcqs:
- Growth of ______________ is promoted by the presence of manganese in water?
A. Files
B. Algae
C. Micro-organisms
D. Mosquitoes - Iron & manganese present as pollutant in water cannot be removed by__________________?
A. Ion exchange process
B. Oxidation followed by settling & filtration
C. Lime soda process or manganese zeolite process
D. Chlorination - Iron & manganese present in the polluted water is removed by __________________?
A. Simple filtration
B. Oxidation followed by settling & filtration
C. Chemical coagulation
D. Chlorination only - Inhalation of silica dust by human being during hand drilling in mica mining, lead & zinc mining, silica refractory manufacture and in foundries causes___________________?
A. Asphyxiation (suffocation)
B. Shortness of breath
C. Tuberculosis
D. All A., B. and C. - Higher concentration of nitrogen dioxide in atmospheric air causes___________________?
A. Cancer
B. Bronchitis
C. Asphyxiation
D. Corrosion - Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps in____________________?
A. Coagulation and flocculation of colloids
B. Oxidation of carbonaceous matter to CO2
C. Nitrification or oxidation of ammonia derived from breakdown of nitrogenous organic matter
to the nitrite and eventually to the nitrate
D. All A., B. and C. - Presence of bacteria in potable (drinking) water causes_________________?
A. Turbidity
B. Disease
C. Bad odour
D. Bad taste & colour - Fluorosis is caused due to the presence of excessive amount of ______________ in drinking water?
A. Mercury
B. Lead
C. Fluoride
D. Arsenic - Presence of nitrogen and phosphorous in waste water discharged into lakes and ponds causes_______________?
A. Foaming
B. Odour nuisances
C. Undesirable plant growth
D. Turbidity - Presence of excess fluorine in water causes__________________?
A. Dental cavity
B. Tooth decay
C. Fluorosis
D. Respiratory disease
