The question pertains to the selection of a coagulant for the removal of phosphates from water. In water treatment processes, coagulants are used to remove impurities, including phosphates, by promoting the agglomeration of particles into larger clusters that can be more easily filtered or settled out.
Explanation of Options:
- Aluminium sulphate: This is a commonly used coagulant in water treatment. It reacts with phosphates to form an insoluble aluminium phosphate compound, which can then be removed by filtration or sedimentation.
- Iron sulphate: Iron compounds can also be used as coagulants; however, aluminium sulphate is preferred for phosphate removal.
- Copper sulphate: Copper sulphate is not typically used as a coagulant in water treatment. It is more commonly used as an algaecide.
- Potassium chromate: This compound is not used as a coagulant. It is, in fact, harmful and not suitable for water treatment.
Conclusion: The most effective and widely utilized coagulant among the given options for the removal of phosphates in water is Aluminium sulphate.
Important Questions from Water Treatment
In the flocculation method of water treatment ______ chemical is added to water.
Which of the following is NOT a chemical coagulant used in water treatment?
Which laboratory test is done to determine approximately the dosage of coagulant?
Statement I): Softening of clear groundwater should be carried out immediately after collection by pumping out, or from springs.
Statement II): Iron and manganese precipitates can foul the exchange medium surface if oxidation occurs in, or prior to, the ion-exchange phase.
Which process is used in water purification?
A. Osmosis
B. Reverse Osmosis
C. Cytolysis
D. Turgor pressure
