This set of Industrial Waste Management Multiple Choice Questions & Answers (MCQs) focuses on “Methods Practiced in Petroleum Industries”.
1. Which of the following materials is not released during petroleum refining?
a) Fly ash
b) Aldehydes
c) Ammonia
d) Odours
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Explanation: Manufacture of construction materials releases fly ash and not petroleum refining. Aldehydes, ammonia and odorous, on the other hand, are all gases released during this process.
2. Where is hydrogen sulphide released from during petroleum refining?
a) Catalyst regeneration
b) From lighter fuel grades
c) Storage tank leaks
d) Pipeline leaks
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Explanation: The stripping of lighter fuel grades releases hydrogen sulphide and mercaptans during the processing of crude. Mercaptans being odorous compounds, are rejected during the refining process.
3. How is refinery wastewater clarified?
a) By flocculation
b) By sedimentation
c) By flotation
d) By clarifiers
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Explanation: Flotation is exclusively used to treat oily wastewaters. First, the effluent is aerated, and then coagulants are added so that oil particles may stick to the coagulants. Once the oil particles coagulate, they are collected from the top layer of the effluent.
4. Why is solvent extraction used for in oil refineries?
a) To recover acetic acid
b) To recover benzene
c) To separate xylene
d) To recover phenolics
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Explanation: Phenolic compounds, which may be present in the effluents, are valuable materials that need recovery. Solvents like xylene and benzene are responsible for the extraction and recovery of these compounds.
5. How is carbon tetrachloride recovered from the effluents of the petrochemical industry?
a) By adsorption
b) By absorption
c) By flocculation
d) By biological treatment
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Explanation: Adsorption is used to collect carbon tetrachloride and carbon disulphide. These are both valuable solvents and may be refined and sold. Activated carbon is used for this process, either in a series or parallel packed bed towers.
6. Which of the following fluids are not recovered from the solvent extraction process in the petrochemical industry?
a) Isobutylene
b) Phenols
c) Paraffins
d) Naphthalenes
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Explanation: Isobutylene, paraffin, and naphthalenes are all collected from the effluents of the petrochemical industries. If desired, these materials can be sold as value-added products upon further purification.
7. Which of the following industries recovers organic acids?
a) Chemical manufacture
b) Fertiliser industry
c) Petrochemical industry
d) Power generation
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Explanation: The petrochemical industry recovers materials like organic acids and alkaloids. Organic acids and alkaloids may be valuable products. The method used for separation from wastewater is ion exchange.
8. How is hydrogen recovered from the petroleum industry?
a) By dialysis
b) By electrodialysis
c) By ion exchange
d) By reverse osmosis
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Explanation: Ion exchange is used for metallic cations. Electrodialysis is an expensive method. Reverse osmosis is an efficient method that uses a semi-permeable membrane to carry out the separation.
9. What is the characteristic of solid waste from the petrochemical industry?
a) Asphalt-like
b) Slimy
c) Fibrous
d) Ashy
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Explanation: The solid waste from the petrochemical industry is usually oily, greasy and asphaltic. These materials float in water. Solid waste from plastic manufacture may be latex or consist of crumbs of plastic.
10. Which particulate matter are scrubbing towers used to collect in petroleum refineries?
a) Fumes
b) Catalyst dust
c) Smoke
d) Fly ash
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Explanation: Catalyst dust and sludge ash are separated from gaseous pollutants with the help of scrubbing towers. There are different kinds of wet scrubbers available like spray towers and packed-bed towers, among others.
11. Which of the following is not present in the wastewater from petrochemical industries?
a) Sulphides
b) Chromates
c) Metals
d) Alkali
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Explanation: Petrochemical effluents have a few inorganic pollutants in them. These are sulphides, chromates and alkalis. Metals are not present because they have no use in the manufacture of petrochemicals.
12. Other than fats and oils, oil manufacture industries release which organic pollutants in their effluents?
a) Proteins
b) Carbohydrates
c) Detergents
d) phenols
View Answer
Explanation: Oil manufacturing industries usually release phenols, fats and oils through their effluents. There is no use for detergents in this industry; proteins and carbohydrates are absent.
13. Once separated from wastewater, how are oil emulsions treated?
a) Thermal treatment
b) Biological treatment
c) Physical treatment
d) They are disposed
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Explanation: Biological treatment or physio-chemical treatment is given to oil emulsions. Here, oils are separated from the effluents, and then finally disposed of in landfills. The question asks for the treatment method.
14. At which stage are oil and grease removed from the petroleum manufacture wastewater?
a) Primary treatment
b) Secondary treatment
c) Advanced treatment
d) It depends
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Explanation: The separation of oil and grease happens at the primary treatment stage. Suspended oil particles are removed using settling methods and clarifiers, so they do not hinder the biological treatment process.
15. Which of the following refining processes does not release sulphides as a primary pollutant?
a) Reforming
b) Distillation
c) Pre-cleaning
d) Cracking
View Answer
Explanation: All the processes listed release sulphides during processing. Crude oils have a high sulphur compound content (1-5%), which is why high sulphide content is present in the wastewater.
Sanfoundry Global Education & Learning Series – Industrial Waste Management.
To practice all areas of Industrial Waste Management, here is complete set of 1000+ Multiple Choice Questions and Answers.
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