PPT: Treatment of Water | Environmental Engineering - Civil Engineering (CE) PDF Download

 Page 1


Water Treatment Processes
Water treatment involves several key processes to ensure safe drinking 
water. These include screening, sedimentation, coagulation, filtration, 
disinfection, aeration, softening, and other specialized treatments.
Page 2


Water Treatment Processes
Water treatment involves several key processes to ensure safe drinking 
water. These include screening, sedimentation, coagulation, filtration, 
disinfection, aeration, softening, and other specialized treatments.
Screening: First Line of Defense
Coarse Screens
Remove large debris like 
branches and trash from 
incoming water.
Fine Screens
Capture smaller particles that 
pass through coarse screens.
Purpose
Protect downstream equipment 
and improve efficiency of 
subsequent processes.
Page 3


Water Treatment Processes
Water treatment involves several key processes to ensure safe drinking 
water. These include screening, sedimentation, coagulation, filtration, 
disinfection, aeration, softening, and other specialized treatments.
Screening: First Line of Defense
Coarse Screens
Remove large debris like 
branches and trash from 
incoming water.
Fine Screens
Capture smaller particles that 
pass through coarse screens.
Purpose
Protect downstream equipment 
and improve efficiency of 
subsequent processes.
Plain Sedimentation
Process
Water is kept in quiescent tanks. 
Suspended matter settles to the 
bottom due to gravity.
Benefits
Removes large suspended impurities. 
Creates more uniform water for further 
treatment.
Economics
Very economical method for initial 
removal of suspended particles.
Page 4


Water Treatment Processes
Water treatment involves several key processes to ensure safe drinking 
water. These include screening, sedimentation, coagulation, filtration, 
disinfection, aeration, softening, and other specialized treatments.
Screening: First Line of Defense
Coarse Screens
Remove large debris like 
branches and trash from 
incoming water.
Fine Screens
Capture smaller particles that 
pass through coarse screens.
Purpose
Protect downstream equipment 
and improve efficiency of 
subsequent processes.
Plain Sedimentation
Process
Water is kept in quiescent tanks. 
Suspended matter settles to the 
bottom due to gravity.
Benefits
Removes large suspended impurities. 
Creates more uniform water for further 
treatment.
Economics
Very economical method for initial 
removal of suspended particles.
Sedimentation with 
Coagulation
Add Coagulants
Chemicals like alum or ferric chloride are mixed with raw water.
Form Flocs
Fine particles clump together, creating larger, heavier flocs.
Allow Settlement
Flocs settle in sedimentation basin, making removal easier.
Page 5


Water Treatment Processes
Water treatment involves several key processes to ensure safe drinking 
water. These include screening, sedimentation, coagulation, filtration, 
disinfection, aeration, softening, and other specialized treatments.
Screening: First Line of Defense
Coarse Screens
Remove large debris like 
branches and trash from 
incoming water.
Fine Screens
Capture smaller particles that 
pass through coarse screens.
Purpose
Protect downstream equipment 
and improve efficiency of 
subsequent processes.
Plain Sedimentation
Process
Water is kept in quiescent tanks. 
Suspended matter settles to the 
bottom due to gravity.
Benefits
Removes large suspended impurities. 
Creates more uniform water for further 
treatment.
Economics
Very economical method for initial 
removal of suspended particles.
Sedimentation with 
Coagulation
Add Coagulants
Chemicals like alum or ferric chloride are mixed with raw water.
Form Flocs
Fine particles clump together, creating larger, heavier flocs.
Allow Settlement
Flocs settle in sedimentation basin, making removal easier.
Filtration: Refining Water 
Quality
Purpose
Removes smaller suspended 
particles, bacteria, and 
microorganisms that remain 
after sedimentation.
Process
Water passes through granular 
media beds like sand or 
anthracite coal, trapping 
contaminants.
Outcome
Significantly improves water clarity and quality before disinfection.