A. Silica
B. Turbidity
C. Phenol
D. Dissolved oxygen
Correct Answer: Silica ✔
Last Updated: July 28, 2023
Related MCQs
- The main pollutant in waste water discharged from a petroleum refinery is oil (both in free and emulsified form). Free oil is removed by__________?
- Noise emitted by a ventilation fan at a distance of 3 metres is about __________ decibels?
- Presence of __________ in water stream are deleterious to aquatic life?
- Tolerable limit of nitrogen oxides in air is __________ ppm?
- BOD of raw municipal sewage may be in the range of about __________ mg/litre?
- Iron & manganese present in the polluted water is removed by __________?
- TLV of aldrin in public water supply system is about __________ μg/litre?
- Aerobic biological oxidation ponds used for the purification of polluted water__________?
- Presence of excess fluorine in water causes__________?
- Direct reaction of unsaturated hydrocarbons with either NO or NO2 produces an eye irritating pollutant compound known as__________?
- Dissolved oxygen content in river water is around __________ ppm?
- Maximum allowable concentration of CO2 in air for safe working is __________ ppm (parts per million)?
- __________ substances present in sewage are removed in grit chamber during sewage treatment?
- Industrial workers working in leather tanning & manufacturing units are prone to suffer from __________?
- Phenolic water generated in coke ovens & by-product plant attached to an integrated steel plant containing phenol in concentration of less than 100 mg/litre can be removed by__________?
- Ionisation potential employed in the industrial electrostatic precipitator is of the order of__________?
- Noise level during normal conversation among men is about __________ decibels?
- Exposure to small amount of __________ results in high blood pressure & heart disease in human beings?
- Which of the following acts as a natural source of air pollution ?
- Moist atmospheric air at high temperature (e.g., in summer) having high concentration of sulphur dioxide causes__________?
- Tri-sodium phosphate is used in boiler water treatment to reduce__________?
- Which of the following is the most major constituents of air pollutants ?
- __________ cannot control the noise pollution ?
- Fluorosis (a bone disease) is caused by the presence of high concentration of __________ in atmospheric air?
- Death may occur, when SO2 concentration in atmospheric air exceeds __________ ppm?
- Sound produced by an automobile horn heard at a distance of 1.5 metres corresponds to about __________ decibels?
- Most of the atmospheric air pollutants are present in large quantity in__________?
- __________ is removed from water by lime-soda process?
- Atmospheric pollution caused by the exhaust gas of supersonic transport air-crafts is mostly in the atmospheric region called__________?
- Septic tanks are used for the __________ of the deposited solids?
- Waste/polluted water discharged from electroplating, blast furnace and coal mining industries contain mainly __________ substances?
- Particulates (< 1μm size) remaining suspended in air indefinitely and transported by wind currents are called__________?
- The type of bacteria which is active in trickling filter during biological treatment of sewage is the __________ bacteria?
- Presence of __________ hardness is responsible for the temporary hardness in water?
- Bag filter design is predominantly dependent on gas temperature, as it affects the gas density & viscosity and the selection of filtering material. The pressure drop in a bag filter is__________?
- Limestone powder is injected during pulverised coal burning in boilers to __________ the flue gases?
- The main industrial source of emission of hydrogen sulphide air pollutant is__________?
- Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by__________?
- Thermal pollution due to excessive heat & temperature in the working place causes__________?
- Irradiation of water by ultraviolet light of suitable wavelength is commonly used for disinfection of water in__________?
- Inhalation of lead compounds present in the automobile exhausts (using leaded petrol) causes__________?
- Pick out the one which is not a chemical coagulant ?
- Presence of dissolved impurities of __________ is responsible for the red brownish color of water?
- The concentration of water vapour in troposphere, which depends upon the altitude & temperature, varies in the range of zero to __________ percent?
- Turbidity of water is an indication of the presence of__________?
- ‘Particulate’ air pollutants are finely divided solids and liquids. Which of the following is not a „particulate‟ ?
- During which of the following operating conditions of an automobile, carbon monoxide content in the exhaust gas is maximum ?
- Carbon monoxide is a pollutant, which causes__________?
- In water treatment, alum [Al2(SO4)3] is used for the process of __________?
- Which of the following is not a secondary air pollutant ?
- Which of the following dust collection equipments is the least efficient (for sub-micronic particles) ?