MCQOPTIONS
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MCQOPTIONS
This section includes 12 Mcqs, each offering curated multiple-choice questions to sharpen your Environmental Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A wastewater treatment plant disposes of its effluent in a surface stream. Characteristics of the stream and effluent are shown below.ParameterWaste waterStream waterWaste water mix stream waterFlow (m3/sec)0.24 Dissolved oxygen, mg/L17 BOD5 at 20°C, mg/L1002 Oxygen consumption rate (K1 at 20°C) (1/day)0.20.20.23Oxygen reaeration rate (K2 at 20°C) (1/day)-0.30.3For 20°C stream water temperature, the equilibrium concentration of oxygen = 9.17 mg/L. Assuming no temperature correction is required, answer the following: Calculate ultimate BOD of wastewater and stream water mix water? |
| A. | 8.5 mg/L |
| B. | 9 mg/L |
| C. | 9.5 mg/L |
| D. | 9.76 mg/L |
| Answer» E. | |
| 2. |
Critical dissolved oxygen (D.O.) deficit occurs in which one of the following zones of pollution of ‘oxygen sag curve’ in case of self-purification of natural streams? |
| A. | Zone of recovery |
| B. | Zone of active decomposition |
| C. | Zone of degradation |
| D. | Zone of clear water |
| Answer» C. Zone of degradation | |
| 3. |
Disposal of sewage in large cities, is done in: |
| A. | Irrigation |
| B. | Dilution |
| C. | Oxidation |
| D. | Putrifaction |
| Answer» C. Oxidation | |
| 4. |
If a sewer carrying a discharge of 3 cumec outfalls into a river having a discharge of 10 cumec and DO equal to 9.1 mg/L the resultant DO of the mix is |
| A. | 7 mg/L |
| B. | 5 mg/L |
| C. | 6 mg/L |
| D. | 8 mg/L |
| Answer» B. 5 mg/L | |
| 5. |
Allowable disposable rate of application of sludge on land is determined by:- |
| A. | Carbon content of sludge |
| B. | Potassium content of sludge |
| C. | Nitrogen content of sludge |
| D. | Phosphorous content of sludge |
| Answer» D. Phosphorous content of sludge | |
| 6. |
In sewers designed with self cleansing velocity. |
| A. | The bottom is silted |
| B. | The bottom is scoured |
| C. | Both silting and scorning occur at the bottom |
| D. | Neither silting nor scouring occur at the bottom |
| Answer» E. | |
| 7. |
Name the pipe which is provided in septic tank for discharge of foul gases. |
| A. | Anti-siphonage pipe |
| B. | Outlet pipe |
| C. | Vent pipe |
| D. | Man hole |
| Answer» D. Man hole | |
| 8. |
Consider the following statements regarding pyrolysis:1. It is an irreversible chemical change brought about by the action of heat in oxygen-free atmosphere.2. Range of temperature is 500°C to 1000°C.3. Internal heating causes organic matter to decompose physically and chemically rather than burn.4. It is a highly exothermic process.Which of the above statements are correct? |
| A. | 1, 2, 3 and 4 |
| B. | 1, 3 and 4 only |
| C. | 2 and 4 only |
| D. | 1, 2 and 3 only |
| Answer» E. | |
| 9. |
A treated wastewater (initial contaminant concentration, flow rate = 5C, 0.2Q) enters a stream (initial concentration, flow rate = 0.01C, Q). Calculate contaminant concentration in stream immediately after mixing of wastewater with stream water? |
| A. | 0.84C |
| B. | 0.04C |
| C. | 1.0Q |
| D. | 1.2Q |
| Answer» B. 0.04C | |
| 10. |
A combined sewer is the one which carries domestic sewage and |
| A. | storm water |
| B. | industrial wastes |
| C. | overhead flow |
| D. | rainwater runoff |
| E. | industrial waste and storm water |
| Answer» B. industrial wastes | |
| 11. |
A waste water stream (flow = 2 m3/sec, ultimate BOD = 90 mg/litre) is joining a small river (flow = 12 m3/s, ultimate BOD = 5 mg/litre). Both water streams get mixed up instantaneously. Cross-sectional area of the river is 50 m2. Assuming the de-oxygenation rate constant, K = 0.25/day the BOD (in mg/litre) of the river water, 10 km downstream of the mixing point is |
| A. | 1.68 |
| B. | 12.63 |
| C. | 15.46 |
| D. | 1.37 |
| Answer» D. 1.37 | |
| 12. |
As per Construction and Demolition Waste Management Rules, 2016, Waste generators who generate more than _______________ per project in a month shall segregate the waste into various streams such as concrete, soil, steel, wood and plastics, bricks and mortar and shall submit waste management plan and get appropriate approvals from the local authority before starting construction or demolition or remodeling work |
| A. | 100 tons |
| B. | 200 tons |
| C. | 300 tons |
| D. | 400 tons |
| Answer» D. 400 tons | |