A. Radioactive
B. Organic
C. Inorganic
D. None of these
Related Mcqs:
- 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. - Oilish impurities present the effluent discharged from the electroplating industry is normally not removed by _____________________?
A. Chemical coagulation
B. Floatation & skimming
C. Centrifugation
D. Ultra filtration - Suspended solid present in the waste water generated in blast furnace gas cooling and cleaning plant is removed by__________________?
A. Biological oxygen pond
B. Radial settling tank (thickener) using coagulant (lime & ferrous sulphate)
C. Lagoons
D. Filtration - The amount of chemical coagulant added for treatment of polluted water ______________ with increase in temperature of the polluted water to be treated?
A. Decreases
B. Increases
C. Remain constant
D. May increase or decrease; depends on the chemical characteristics of polluted water - 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 - The main pollutant in waste water discharged from a petroleum refinery is oil (both in free and emulsified form). Free oil is removed by_________________?
A. Biological oxygen pond
B. Aerated lagoons
C. Trickling filters
D. Gravity separator having oil skimming devices - Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by________________?
A. Natural aeration of water stream
B. Photosynthetic action of algae
C. Both A. & B.
D. Neither A. nor B. - Radioactive substances present in the polluted water stream can be removed by_________________?
A. Biological oxygen treatment
B. Coagulation and filtration
C. Adsorption in ion exchange materials
D. None of these - Thermal pollution of water increases its toxicity and oxidation of oxygen demanding waste besides favouring bacterial growth. A rise in water temperature by 10°C, doubles the toxic effects of _____________ present in it?
A. Coal ash
B. Potassium cyanide
C. Ortho-xylene
D. None of these - Coal washing waste water containing about 3% suspended solids (comprising of clay, slate, stone etc.) is treated for solid particles removal ?
A. By chemical coagulation
B. In sedimentation tanks equipped with mechanical scrapper
C. In vacuum filter
D. In clarifiers
