Environmental Engineering Flashcards
Suspended solid present in the waste water generated in blast furnace gas cooling and cleaning plant is removed by
radial settling tank (thickener) using coagulant (lime & ferrous sulphate)
Persons working in cement plants and limestone quarries are more prone to disease like
silicosis
Particulates (< 1μm size) remaining suspended in air indefinitely and transported by wind currents are called
aerosols
Operating principle of cyclone separator is based on the action of __________ dust particles.
centrifugal force on
Exposure to small amount of __________ results in high blood pressure & heart disease in human beings.
cadmium
Maximum allowable concentration of CO2 in air for safe working is __________ ppm (parts per million).
5000
Tolerable limit of nitrogen oxides in air is __________ ppm.
5
Iron & manganese present as pollutant in water can not be removed by
chlorination
In water chemical treatment plant, use of chloramines ensures
disinfection
Which of the following is the common pollutant emitted from metallurgical smelters, thermal power plant and cement plants ?
SO2
During which of the following operating conditions of an automobile, carbon monoxide content in the exhaust gas is maximum ?
Idle running
H2S present in gaseous stream can be removed by adsorption on
bog iron
Inhalation of lead compounds present in automobile exhaust (using leaded petrol) causes
all (a), (b) & (c)
Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by
both (a) & (b).
Aerodynamic noise resulting from turbulent gas flow is the most prevalent source of valve noise in fluid allow control. It is caused due to
both (a) & (b)
Smoke is produced due to
all (a), (b) and (c).
fluorosis (a bone disease) is caused by the presence of high concentration of __________ in atmospheric air.
hydrogen fluoride
Threshold Limit Value (TLV) is the maximum allowable concentration (i.e. safe limit) of pollutants in air. Safe limit for SO2 in air is __________ ppm.
5
Main pollutants released from iron & steel industry is
CO, CO2 & SO2.
Scale formation in boiler is controlled by
reduction in hardness, silica & alumina in feed water.
Which is the best and the most effective method for the removal of organic contaminant present in the polluted water in very small quantity (say < 200 mg/litre)?
Activated carbon adsorption
Which is a secondary air pollutant ?
Photochemical smog
Which of the following is the most detrimental for water used in high pressure boiler ?
Silica
Turbidity of water is an indication of the presence of
suspended inorganic matter