This set of Industrial Waste Management Multiple Choice Questions & Answers (MCQs) focuses on “Methods Practiced in Textile Industries”.
1. Which of the following inorganic pollutants is absent from textile effluents?
a) Cyanides
b) Acids
c) Bases
d) Bleaches
View Answer
Explanation: Effluents from textile industries contain many kinds of waste materials. Bleaching is done on clothes to whiten them. Acid and bases have many purposes, one of them being dyeing. On the other hand, cyanides do not have applications in the textile industry.
2. Textile industry is the second-highest consumer of water.
a) True
b) False
View Answer
Explanation: Water has various essential uses in the textile industry. Fabrics are dyed using dyes, which need water as solvents. Additionally, water is required to wash and clean textiles.
3. At which stage are reactive dyes removed from textile effluents?
a) Primary treatment stage
b) Secondary treatment stage
c) Tertiary treatment stage
d) Advanced treatment stage
View Answer
Explanation: Removal of reactive dyes is done with the help of microorganisms used in biological reactions. Since the biological method is a secondary treatment method, the removal of reactive dyes occurs at this stage.
4. Which gas is released during the printing process in textile industries?
a) Dinitrogen tetraoxide
b) Nitrogen dioxide
c) Nitrous oxide
d) Ammonia
View Answer
Explanation: The release of hydrocarbons and ammonia occurs during the printing process in the textile industries. The emissions released during the printing process are the source of the waste gases.
5. Effluents from textile industries contain detergents.
a) True
b) False
View Answer
Explanation: Detergents are present in effluents from textile industries. Fabrics need cleaning and washing to remove dirt from them. Phosphates present in detergents may promote eutrophication due to nutrient excess.
6. Which of the following is NOT a source of oil mists in textile industries?
a) Calendaring
b) Bleaching
c) Drying
d) Curing
View Answer
Explanation: Materials that vaporise upon application of heat produce oil mists. An example of such a material is lubricating oil. Such materials are used in the calendaring, drying and curing processes.
7. How is the removal of detergent surfactants from textile effluents carried out?
a) Adsorption by alumina
b) Solvent extraction by benzene
c) Adsorption by activated carbon
d) Solvent extraction by xylene
View Answer
Explanation: The removal of detergent surfactants is done with adsorption. Activated carbon is used as an adsorbent because it is efficient at adsorbing soluble organic compounds like surfactants.
8. Reverse osmosis is used to recover chemicals from the textile industry. Which of the following is NOT one of these chemicals?
a) Pickling liquors
b) Polyvinyl alcohols
c) Mineral oils
d) Phenols
View Answer
Explanation: Phenols, if present, are removed by solvent extraction, not reverse osmosis. Another method of removal is by way of stripping. In reverse osmosis, a semi-permeable membrane is used, which is ideal for the recovery of the other given options.
9. In textile industries, rayon is recovered using which method?
a) Dialysis
b) Flotation
c) Adsorption
d) Ion exchange
View Answer
Explanation: Dialysis is used to recover rayon, which is an advanced treatment method. The separation is carried out based on molecular sizes of dissolved solids. The other options are incorrect based on his criteria.
10. At which stage are oils and greases removed from textile wastewater?
a) Primary treatment
b) Secondary treatment
c) Tertiary treatment
d) Advanced treatment
View Answer
Explanation: Oils and greases are broken-down by microorganisms. This process is a biological treatment which falls in the second stage. Phenols, BOD, and colour are other materials removed at this stage.
11. Which method is used commonly for the primary treatment of textile effluents?
a) Landfills
b) Fabric filters
c) Flocculation
d) Aerobic filters
View Answer
Explanation: Flocculation sedimentation successfully removes the suspended and colloidal solids in the wastewater. These solids are first coagulated to form flocs then they settle at the bottom of the tanks.
12. Which of the following is used commonly as a secondary treatment method for the treatment of textile wastewater?
a) Nitrification
b) Sedimentation
c) Reverse osmosis
d) Aerated lagoons
View Answer
Explanation: This method has a high removal efficiency for BOD and phosphorus. Even suspended solids settle over the period of treatment and are, therefore, removed. Other methods include activated sludge process and trickling filters. None of the other options listed is a secondary treatment method.
13. Which heavy metal is recovered from precipitation during rayon manufacture?
a) Cadmium
b) Zinc
c) Mercury
d) Lead
View Answer
Explanation: Acidic wastewater from rayon plants consists of heavy metal zinc. Chemical precipitation is used to recover it. It is an easy and economical method to ensure high recovery percentages.
14. What is the final treatment method used for dyes and dye-intermediates?
a) Chemical
b) Physical
c) Thermal
d) Biological
View Answer
Explanation: Since dyes are hazardous, they are thermally treated once they are separated from effluents. Incineration is the thermal treatment method used. Once incinerated, the ash is sent to a landfill.
15. Which of the following two heavy metals are recovered from textile industries?
a) Chromium and mercury
b) Titanium and Mercury
c) Mercury and Zinc
d) Chromium and cadmium
View Answer
Explanation: Although zinc is present in textile industry effluents, mercury is not. Chromium is present, but mercury is not. Neither titanium nor mercury is present. Both chromium and cadmium are present.
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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