1
Question
In the sewage treatment process _____A_____ are easy to remove from wastewater whereas _____B_____are difficult to remove.
In the sewage treatment process _____A_____ are easy to remove from wastewater whereas _____B_____are difficult to remove.
Open in App
Solution
The correct option is B A - solids, B - dissolved salts
The polluted form of water generated due to human activities is called the sewage.
Wastewater treatment is a process which is used to remove contaminants from the waste water and convert it into an effluent that can be returned to the natural water bodies.
Domestic sewage contains impurities (0.1%) in the form of suspended solids (sand, clay and silt), colloids (fecal matter, bacteria and paper fibres) and dissolved materials (nitrates, ammonia, sodium, calcium etc.).
In the sewage treatment process solids can be removed easily by physical removal. It is done through filtration and sedimentation. In filtration, water flows through a filter made of gravel or sand such that large sized particles that cannot pass through the filter pores are separated out. Soil and small pebbles can be easily removed by sedimentation. It is the process of letting suspended material settle by gravity.
Colloids and dissolved salts cannot be easily removed by sedimentation or filtration. Colloids can be separated by the process of chemical coagulation. Removal of dissolved salts requires treatments like physical adsorption (molecules are attached to the surface), reverse osmosis (water passes through a porous membrane, under pressure from its lower concentration to its higher concentration) etc, which requires expertise and machinery.
Hence option b is correct.
The polluted form of water generated due to human activities is called the sewage.
Wastewater treatment is a process which is used to remove contaminants from the waste water and convert it into an effluent that can be returned to the natural water bodies.
Domestic sewage contains impurities (0.1%) in the form of suspended solids (sand, clay and silt), colloids (fecal matter, bacteria and paper fibres) and dissolved materials (nitrates, ammonia, sodium, calcium etc.).
In the sewage treatment process solids can be removed easily by physical removal. It is done through filtration and sedimentation. In filtration, water flows through a filter made of gravel or sand such that large sized particles that cannot pass through the filter pores are separated out. Soil and small pebbles can be easily removed by sedimentation. It is the process of letting suspended material settle by gravity.
Colloids and dissolved salts cannot be easily removed by sedimentation or filtration. Colloids can be separated by the process of chemical coagulation. Removal of dissolved salts requires treatments like physical adsorption (molecules are attached to the surface), reverse osmosis (water passes through a porous membrane, under pressure from its lower concentration to its higher concentration) etc, which requires expertise and machinery.
Hence option b is correct.
Suggest Corrections
0
Similar questions
View More
Join BYJU'S Learning Program
Explore more
Join BYJU'S Learning Program
