Bioprocess Engineering Multiple Choice Questions on “By-Products”.
1. What is the term “Gin”?
A. A magical spirit
B. Liquor
C. Non-liquor
D. Gas
Answer: B
Explanation: Gin is liquor which derives its predominant flavour from juniper berries (Juniperus communis). Gin is one of the broadest categories of spirits, all of various origins, styles, and flavour profiles that revolve around juniper as a common ingredient.
2.What do you mean by “Stillage”?
A. Still water
B. Still waste
C. Storage and transport
D. Growth medium
Answer: C
Explanation: A stillage is like a pallet or skid but with a cage or sides or some form of support specifically tailored to the material it is intended to carry. Some are designed to be stackable. A stillage is any device on which a cask of ale is placed for service.
3. The color of the beer is proportional to the roasting of grains.
A. True
B. False
Answer: A
Explanation: Naturally, the roasting process has a considerable impact on the flavor of the beer. The more the grain is roasted, the more complex and rich the brew becomes. In particular, roasting tends to bring out stronger flavor notes, including chocolate and toffee. Darker beers also tend to have a higher alcohol content than light beers. The darker the grain, the darker the beer.
4. Single cell protein cannot be produced from stillage.
A. True
B. False
Answer: B
Explanation: A number of processes to produce SCP from stillage using specific microbes like Geotrichum candidum, Candida utilis or C.tropicalis.
5. Silage is not a feremented fodder.
A. True
B. False
Answer: B
Explanation: Silage is fermented, high-moisture stored fodder which can be fed to cattle, sheep and other such ruminants (cud-chewing animals) or used as a biofuel feedstock for anaerobic digesters. It is fermented and stored in a process called ensilage, ensiling or silaging, and is usually made from grass crops, including maize, sorghum or other cereals, using the entire green plant (not just the grain). Silage can be made from many field crops, and special terms may be used depending on type: oatlage for oats, haylage for alfalfa.
6. What are Hops?
A. A flower
B. A fruit
C. A vegetable
D. A horse shoe
Answer: A
Explanation: Hops are the flowers (also called seed cones or strobiles) of the hop plant Humulus lupulus They are used primarily as a flavoring and stability agent in beer, to which they impart bitter, zesty, or citric flavours; though they are also used for various purposes in other beverages and herbal medicine.
7. “The yeast may also be used directly as a source of vitamin”. Is the statement True or False?
A. True
B. False
Answer: A
Explanation: The yeast may also be used directly as a source of vitamins. If it is to be used as a human food it must be debittered to remove the hop bitter substances absorbed on to the yeast cells.
8. Amino acid waste cannot be used as a fertilizer.
A. True
B. False
Answer: B
Explanation: The main wastes from glutamic acid or lysine fermentations are cells, a liquor with a high amino-acid content which can be used as an animal-feed supplement, and the salts removed from the liquor by crystallization, which is a good fertilizer.
9. The baker’s yeast are now produced as a brewery by-product.
A. True
B. False
Answer: B
Explanation: Although baker’s yeast was originally obtained as a brewery by-product, this market has diminished considerably. Most baker’s yeast is now produced directly by a distinct production process.
10. What is the sludge thickener?
A. Increasing the sludge volume
B. Reducing the sludge volume
C. Constant sludge volume
D. The second step of concentration of sludge
Answer: B
Explanation: Thickening is the first step for reducing the sludge volume by removal of free sludge water. Thin sludge is concentrated to thick sludge. Thick sludge has a higher viscosity, but must still be pumpable. Sludge settles in gravity thickeners and is compressed by the weight of its own solids.
11. What can sludge from a sewage treatment plant be used?
A. Non-organic solid formation
B. Non-biosolid formation
C. Waste formation
D. Biosolid formation
Answer: D
Explanation: Biosolids is a term often used in conjunction with reuse of sewage solids after sewage sludge treatment. Biosolids can be defined as organic wastewater solids that can be reused after stabilization processes such as anaerobic digestion and composting.
12. What is activated sludge?
A. Separation of liquid and solid phase
B. Product of wastewater treatment
C. Type of wastewater treatment
D. Suspended solids
Answer: C
Explanation: The activated sludge process is a type of wastewater treatment process for treating sewage or industrial wastewaters using aeration and a biological floc composed of bacteria and protozoa.
13. What is dewatered sludge?
A. Separation of liquid and solid phase
B. Product of wastewater treatment
C. Type of wastewater treatment
D. Suspended solids
Answer: A
Explanation: Sludge dewatering is the separation of a liquid and solid phase whereby, generally, the least possible residual moisture is required in the solid phase and the lowest possible solid particle residues are required in the separated liquid phase (“the centrate”).
14. What is sewage sludge?
A. Separation of liquid and solid phase
B. Product of wastewater treatment
C. Type of wastewater treatment
D. Suspended solids
Answer: B
Explanation: Sewage sludge is a product of wastewater treatment. Wastewater and stormwater enter the sewage system and flow into wastewater treatment facilities, where the solid wastes are separated from the liquid wastes through settling. At this point, they are processed and “digested”, or decomposed by bacteria.
15. What is a primary sludge?
A. Separation of liquid and solid phase
B. Capture of suspended solids
C. Type of wastewater treatment
D. Suspended solids
Answer: B
Explanation: Primary sludge is a result of the capture of suspended solids and organics in the primary treatment process through gravitational sedimentation, typically by a primary clarifier. The secondary treatment process uses microorganisms to consume the organic matter in the wastewater.