MCQOPTIONS
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MCQOPTIONS
This section includes 15 Mcqs, each offering curated multiple-choice questions to sharpen your Waste Water Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
What is the recommended surface loading rate in case of alum floc suspension? |
| A. | 30-70 m3/m2.d |
| B. | 10-30 m3/m2.d |
| C. | 70-100 m3/m2.d |
| D. | <10 m3/m2.d |
| Answer» B. 10-30 m3/m2.d | |
| 2. |
Why is Ferric ammonium sulfate generally not used as a coagulant? |
| A. | It is very expensive |
| B. | It is dependent on the Dissolved oxygen present in the waste water |
| C. | It is a very slow process |
| D. | It works only at high pH |
| Answer» C. It is a very slow process | |
| 3. |
Along with ferrous sulphate what other chemical is added in order to bring about precipitation? |
| A. | Alum |
| B. | PAC |
| C. | Lime |
| D. | Polyelectrolyte |
| Answer» D. Polyelectrolyte | |
| 4. |
When alum is added to the waste water containing calcium ions which compound is formed as a precipitate? |
| A. | Al(OH)3 |
| B. | Al2 (SO4)3 |
| C. | Ca(OH)2 |
| D. | CaCO3 |
| Answer» B. Al2 (SO4)3 | |
| 5. |
What is the one disadvantage of adding chemicals to bring about precipitation? |
| A. | The TSS increases |
| B. | The TDS increases |
| C. | BOD increases |
| D. | It imparts colour |
| Answer» C. BOD increases | |
| 6. |
Out of these which is not used as a chemical coagulant? |
| A. | Alum |
| B. | Calcium chloride |
| C. | Ferric Chloride |
| D. | Poly Iron Chloride |
| Answer» E. | |
| 7. |
Iron precipitation occurs at which pH? |
| A. | 1-3 |
| B. | 3-5 |
| C. | 5-7 |
| D. | 7-9 |
| Answer» E. | |
| 8. |
Alum precipitation occurs at which pH? |
| A. | 1-3 |
| B. | 3-5 |
| C. | 5-7 |
| D. | 7-9 |
| Answer» D. 7-9 | |
| 9. |
Macro flocculation is brought about by which phenomenon? |
| A. | Velocity gradient |
| B. | Differential settling |
| C. | Brownian movement |
| D. | Differential mixing |
| Answer» B. Differential settling | |
| 10. |
Microflocculation is brought about by which phenomenon? |
| A. | Velocity gradient |
| B. | Differential settling |
| C. | Brownian movement |
| D. | Differential mixing |
| Answer» D. Differential mixing | |
| 11. |
What is the speed of the impeller in a flash mixer? |
| A. | 90 rpm |
| B. | 100 rpm |
| C. | 110 rpm |
| D. | 120 rpm |
| Answer» D. 120 rpm | |
| 12. |
What is the density of alum content used in water treatment? |
| A. | 9.8 lb/gal |
| B. | 10.1 lb/gal |
| C. | 11.1 lb/gal |
| D. | 9.2 lb/gal |
| Answer» D. 9.2 lb/gal | |
| 13. |
The agglomeration of destabilized particles into large particles is called _________ |
| A. | Sedimentation |
| B. | Coagulation |
| C. | Flocculation |
| D. | Disinfection |
| Answer» D. Disinfection | |
| 14. |
What is the first step in clarification? |
| A. | Sedimentation |
| B. | Coagulation |
| C. | Flocculation |
| D. | Screening |
| Answer» C. Flocculation | |
| 15. |
Clarification removes most of the turbidity. |
| A. | True |
| B. | False |
| Answer» B. False | |