This set of Industrial Waste Management Multiple Choice Questions & Answers (MCQs) focuses on “Methods Practiced in Fertiliser Industries”.
1. Fertiliser effluents may contain which of the following nutrients?
a) Phosphorus and nitrogen
b) Phosphorus and oxygen
c) Nitrogen and hydrogen
d) Potassium and oxygen
View Answer
Explanation: Effluents from fertiliser industries may contain nitrogen and phosphorus, both of which are plant nutrients. An excess of these nutrients, though, may result in the excess growth of algae. Eutrophication may result as a consequence.
2. Mercury is present in the effluents of which of the following industries?
a) Textile
b) Fertilisers
c) Tanneries
d) Food
View Answer
Explanation: The effluents from fertiliser industries may contain mercury. Mercury is a toxic heavy metal, and its consumption (even in small dosages) may result in poisoning of the animal species that consume it.
3. How is phosphorus removed from fertiliser effluents?
a) By the addition of acid
b) By the addition of activated carbon
c) By the addition of lime
d) By the removal of phosphorus salts
View Answer
Explanation: Phosphorus is removed from the effluents using either lime or alum. Phosphorus salts are precipitated by the addition of lime and later settle in the conduit. The collection is done either in the primary or secondary treatment stages.
4. Which of the following methods is NOT used by fertiliser industries to remove nitrogen from their effluents?
a) Nitrogen stripping
b) Ion exchange
c) Biological treatment
d) Flocculation
View Answer
Explanation: Except for flocculation, all the methods listed are feasible for nitrogen removal. Nitrogen is not present in the form of suspended solids for this to be feasible. The other methods are chosen based on efficiency desired and costs.
5. Most of the effluents released from the fertiliser industry is from the ammonia and urea manufacture.
a) True
b) False
View Answer
Explanation: Ammonia and urea manufacture account for the bulk of the wastewater produced from the fertiliser industries. Notably, utility water, used for steam generation and cooling, are released into water bodies.
6. Which of the following is untrue about the effluents from the fertiliser industry?
a) Arsenic is present in them
b) Phenols are present in them
c) Oil is present in them
d) Phosphates are present in them
View Answer
Explanation: Phenols are absent from effluents from the fertiliser industry. Arsenic, oils and phosphates are commonly present in these effluents, because of the processing conditions and raw materials, et cetera.
7. How are highly acidic wastewaters neutralised?
a) By the addition of water
b) Nothing specific is done
c) By the addition of lime
d) By the addition of sulphuric acid
View Answer
Explanation: Lime is used to neutralise acidic wastewater. Sometimes, alkaline and acidic effluent streams are mixed to achieve neutralisation. Sulphuric acid is used for the neutralisation of alkaline wastewaters.
8. How is arsenic removed from effluents from the fertiliser industry?
a) By reduction
b) By oxidation
c) By neutralisation
d) By filtration
View Answer
Explanation: Arsenic is removed by filtration with carbon filters. It is then concentrated by continuous filtration and finally, recovered. Otherwise, it is disposed of in containers buried far away from the coast.
9. How are fluorides recovered from the effluents of the fertiliser industry?
a) Adsorption
b) Ion exchange
c) Dialysis
d) Reverse osmosis
View Answer
Explanation: Adsorption is used to recover fluorides from the fertiliser industries. Fluorides get adsorbed onto the surface of adsorbents like activated carbon. This adsorption is carried out in packed towers, either of a fixed bed or moving bed types.
10. Once recovered from effluents, what is the first step in the disposal of solid waste in the fertiliser industry?
a) Solidification
b) Detoxification
c) Landfilled
d) Gasification
View Answer
Explanation: Upon recovery, solid wastes are detoxified using a thermal or biological treatment method. Then they are solidified with additives like cement to prevent mobilisation, and finally, sent to a landfill.
11. When fertilisers are sprayed onto crops, which of the following metals gets suspended into the atmosphere?
a) Zinc
b) Chromium
c) Arsenic
d) Titanium
View Answer
Explanation: Arsenic particles may become airborne when fertilisers are used on crops. Other heavy metals like lead may also have the same fate. Such metals may commonly be present in micronutrient fertilisers.
12. How is ammonia recovered from gaseous effluents of fertiliser industries?
a) Absorption with benzene
b) Absorption with xylene
c) Absorption with chloroform
d) Absorption with sulphuric acid
View Answer
Explanation: Ammonia is recovered using gas absorption. Solvents like sulphuric acid and nitric acid are used for this scrubbing process. The absorption tower may be of tray type, packed bed type.
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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