Drinking water treatment Flashcards
Process for surface water treatment
1) screen filter
2) coagulation-flocculation
3) sedimentation
4) filtration
5) disinfection
define coagulation-flocculation
causes dissolved and suspended particles to form larger particles.
process of coagulation-flocculation
1) add coagulent: aluminum iron
- destabilizes particles to make them sticky
2) flocs form: sticks together to cause groups of particles
3) sedimentation: allows particles to settle due to gravity from weight of particles
what occurs during filtation after coagulation-flocculation
1) filters out suspended particles/ microorganisms
2) through filter material: sand
3) overtime biofilm appears on sand: also gets rid of other pathogens
what does CT stand for?
The measure disinfectat effectiveness.
C= cocentration of disinfectant
T= time requred to inactivate certain % of microorganisms
The lower CT, the faster/easier/more effective to kill pathogen.
types of disinfectants
chlorine, cloramine, chlorine dioxide, ozone, UV light
results of chlorine
worst forming DBP.
organic material+chlorine= chlorinated organic compound= bad chemicals
causes cancer causing chemicals
oxidizing agent
what does DBP stand for?
Disinfection By Products
Results of chloramine
Chlorine+amines
not as effective killing pathogens.
need large quantities(money)
does not form as many DBPs
results of chlorine dioxide
need to generate on-site.
relatively effective.
fewer DBP.
Results of Ozone
very expensive.
must be generated on site.
no residual
Results of UV light
changes shape of DNA, cannot replicate= dead cell
no residual.
very effective.
does not penetrate very far.
algae can grow on lights/poles.
advantages of PCR
rapid results.
highly sensitive.
highly specific.
ability to detect non cultureable viruses.
ability to tailor primers for desired application.
limitations of PCR
High potential for contamination
Potential for amplification of non-target sequences
Small equivalent sample volume analyzed (0.3 - 3 L)
Quantitation?
Inability to distinguish between infective and non-infective particles
Immunomagnetic Separation
Magnet particle + antivirus antibody
