21. Which of the following affects the ozone concentration in troposphere? A. CO B. N2 C. SO2 D. CO2 Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B No explanation is given for this question Let's Discuss on Board
22. After sedimentation, the water is next passed through sand filter beads, a process which removes . . . . . . . . bacteria. A. 70% B. 80% C. 90% D. 99% Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
23. A bacterium useful in bioleaching of metals from low grade ores is A. Bacillus megaterium B. Thermus aquaticus C. Thiobacillus ferrooxidans D. Rhodopseudomonas capsulatus Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C No explanation is given for this question Let's Discuss on Board
24. The combination of primary and secondary treatment reduces the original sewage BOD by A. 30 - 40% B. 50 - 60% C. 60 -70% D. 80 - 90% Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C No explanation is given for this question Let's Discuss on Board
25. Which of the following industries do not produce hazardous waste? A. Electroplating B. Chemical C. Sugar D. Pharmaceutical Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
26. Ballast water may be carried on-board by ships to maintain stability and improve manoeuvrability during transit. Introduction of which one of the following is regarded as the major threat in release of untreated ballast water? A. Pathogenic microbes B. Terrestrial inputs of pollutants C. Invasive marine species D. Algal blooms Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C No explanation is given for this question Let's Discuss on Board
27. The enteroviruses are the ones most commonly found in sewage, they include A. Polio virus B. Coxsackie virus C. Echo virus D. All the above Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
28. Which one of the following is not biodegradable? A. Vegetables B. Fruits C. Earthworm D. Aluminium foil Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
29. Plants suitable for bio monitoring of SO2 pollution are A. White pine, Moss and Lichens B. Tobacco, Grapes and Garden bean C. Apricot, Peach and Gladiolas D. Tomato and Lettuce Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
30. In colloidal chemical substance, the light undergoes A. Diffraction B. Polarization C. Scattering D. Total internal reflection Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C No explanation is given for this question Let's Discuss on Board
