# GATE Questions & Answers of Air Pollution Civil Engineering

#### Air Pollution 19 Question(s)

There are 20,000 vehicles operating in a city with an average annual travel of 12,000 km per vehicle. The NOx emission rate is 2.0 g/km per vehicle. The total annual release of NOx will be

In the figures, Group I represents the atmospheric temperature profiles (P, Q, R and S) and Group II represents dispersion of pollutants from a smoke stack (1, 2, 3 and 4). In the figures of Group I, the dashed line represents the dry adiabatic lapse rate, whereas the horizontal axis represents temperature and the vertical axis represents the altitude.

The correct match is

A coal containing 2% sulfur is burned completely to ash in a brick kiln at a rate of 30 kg/min. The sulfur content in the ash was found to be 6% of the initial amount of sulfur present in the coal fed to the brick kiln. The molecular weights of S, H and O are 32, 1 and 16 g/mole, respectively. The annual rate of sulfur dioxide $(S0_2)$ emission from the kiln (in tonnes/year, up to two decimal places) is ______

Which one of the following is NOT present in acid rain?

Following observations have been made for the elevation and temperature to ascertain the stability of the atmosphere:

 Elevation (in m) Temperature (in C) 10 15.5 60 15.0 130 14.3

The atmosphere is classified as

Pre-cursors to photochemical oxidants are

It was decided to construct a fabric filter, using bags of 0.45 m diameter and 7.5 m long, for removing industrial stack gas containing particulates. The expected rate of airflow into the filter is 10 m3/s. If the filtering velocity is 2.0 m/min, the minimum number of bags (rounded to nearest higher integer) required for continuous cleaning operation is

An electrostatic precipitator (ESP) with 5600 m2 of collector plate area is 96 percent efficient in treating 185 m3/s of flue gas from a 200 MW thermal power plant. It was found that in order to achieve 97 percent efficiency, the collector plate area should be 6100 m2. In order to increase the efficiency to 99 percent, the ESP collector plate area (expressed in m2) would be ______

The atmospheric layer closest to the earth surface is

The sound pressure (expressed in µPa) of the faintest sound that a normal healthy individual can hear is

The concentration of Sulphur Dioxide (SO2) in ambient atmosphere was measured as 30 $\mathrm{\mu }$g/m3. Under the same conditions, the above SO2 concentration expressed in ppm is ___.

Given: P/(RT) = 41.6 mol/m3; where, P = Pressure; T = Temperature; = universal gas constant; Molecular Weight of SO2 = 64.

Consider four common air pollutants found in urban environments, NO, SO2, Soot and O3. Among these which one is the secondary air pollutant?

Total suspended particulate matter (TSP) concentration in ambient air is to measured using a high volume sampler. The filter used for this purpose had an initial dry weight of 9.787g. The filter was mounted in the sampler and the initial air flow rate through the filter was set at 1.5 m3/min. Sampling continued for 24 hours. The air flow after 24 hours was measured to be 1.4 m3/min. The dry weight of the filter paper after 24 hour sampling was 10.283g. Assuming a linear decline in the air flow rate during samplings what is the 24 hour sampling was 10.283g. Assuming a linear decline in the air flow rate during sampling, what is the 24 hour average TSP concentration in the ambient air?

An air parcel having 40ºC temperature moves from ground level to 500 m elevation in dry air following the “adiabatic lapse rate”. The resulting temperature of air parcel at 500m elevation will be

Particulate matter (fly ash) carried in effluent gases from the furnaces burning fossil fuels are better removed by

Two primary air pollutants are