What is formed when coagulant is added to water?a)Scumb)Soapc)Bubblesd...
Explanation: When coagulant is added to water, then white gelatinous precipitate is formed called as floc.
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What is formed when coagulant is added to water?a)Scumb)Soapc)Bubblesd...
Introduction:
When coagulant is added to water, a process called coagulation occurs. Coagulation is an important step in water treatment, as it helps in removing suspended particles and colloidal substances from the water. The addition of coagulant leads to the formation of floc, which aids in the removal of impurities during sedimentation and filtration processes.
Coagulation and coagulants:
Coagulation is the process of destabilizing and aggregating particles in water to form larger particles called floc. Coagulants are chemicals that are added to water to facilitate this process. Common coagulants used in water treatment include aluminum sulfate (alum), ferric chloride, and polyaluminum chloride.
Formation of floc:
When coagulant is added to water, several reactions occur that lead to the formation of floc. These reactions involve the neutralization of charges on suspended particles and the formation of precipitates. The coagulant reacts with the water and the impurities present to form insoluble hydroxides or other precipitates.
Neutralization of charges:
Most suspended particles in water carry a negative charge due to the presence of ions or surface functional groups. The coagulant disrupts the stability of these charges by neutralizing them. For example, aluminum sulfate dissociates in water to form aluminum hydroxide and sulfate ions. The aluminum hydroxide species react with the negatively charged particles, reducing their repulsive forces and allowing them to come closer to each other.
Formation of precipitates:
Once the charges on the particles are neutralized, the coagulant species can form precipitates with the impurities in water. These precipitates can be in the form of metal hydroxides, metal sulfides, or other insoluble compounds. The precipitates act as nuclei for the aggregation of suspended particles, leading to the formation of floc.
Importance of floc formation:
The formation of floc is crucial in water treatment processes such as sedimentation and filtration. The floc particles are larger and heavier than the original suspended particles, making them easier to separate from the water. During sedimentation, the floc settles to the bottom of a sedimentation basin, allowing clear water to be separated from the settled solids. In filtration, the floc particles are trapped by the filter media, further removing impurities from the water.
Conclusion:
When coagulant is added to water, it facilitates the process of coagulation, resulting in the formation of floc. The coagulant neutralizes charges on suspended particles and forms insoluble precipitates, which then aggregate to form larger floc particles. This floc aids in the removal of impurities during sedimentation and filtration processes, leading to cleaner and clearer water.