Environmental Engineering in CE Lagoons used for purification of polluted water All of these Use micro-organisms/bacteria in presence of dissolved oxygen Are large shallow artificial lakes also known as clarification lakes, maturation ponds or oxidation ponds Gives an excellent final effluent (with 3 to 4 lagoons arranged in series) having suspended solid < 1 mg/litre and BOD = 3.8 mg/litre All of these Use micro-organisms/bacteria in presence of dissolved oxygen Are large shallow artificial lakes also known as clarification lakes, maturation ponds or oxidation ponds Gives an excellent final effluent (with 3 to 4 lagoons arranged in series) having suspended solid < 1 mg/litre and BOD = 3.8 mg/litre ANSWER DOWNLOAD EXAMIANS APP
Environmental Engineering in CE The density of the gases (present in air) decreases with increasing altitude to such an extent, that about 70% of the mass of atmospheric air is found in the lower 5 km. of the atmosphere. This lower region of atmosphere is called the Stratosphere None of these Troposphere Ionosphere Stratosphere None of these Troposphere Ionosphere ANSWER DOWNLOAD EXAMIANS APP
Environmental Engineering in CE Workers working in __________ industry are most prone to white lung cancer. Coal mining Limestone mining Textile Asbestos Coal mining Limestone mining Textile Asbestos ANSWER DOWNLOAD EXAMIANS APP
Environmental Engineering in CE Hydrogen ion concentration in distilled water is 7 x 10⁻⁷ 10⁷ 7 x 10⁷ 10⁻⁷ 7 x 10⁻⁷ 10⁷ 7 x 10⁷ 10⁻⁷ ANSWER DOWNLOAD EXAMIANS APP
Environmental Engineering in CE Tolerable limit of nitrogen oxides in air is __________ ppm. 1 5 0.1 25 1 5 0.1 25 ANSWER DOWNLOAD EXAMIANS APP
Environmental Engineering in CE The amount of coagulant needed for coagulation of water increases with(i) Increase in turbidity of water(ii) Decrease in turbidity of water(iii) Increase in temperature of water(iv) Decrease in temperature of waterThe correct answer is (ii) and (iii) (i)and(iv) (i) and (ii) (ii) and (iv) (ii) and (iii) (i)and(iv) (i) and (ii) (ii) and (iv) ANSWER DOWNLOAD EXAMIANS APP