Wastewater & Excreta Disposal Flashcards
Differentiate sewage from sullage
Sewage: excreta + significant food residue + toxic chemicals
Sullage: residue fr washing, bathing, lab process, tech process
When solid fraction is high, turbidity happens. What treatment is needed?
A.primary
B.secondary
C.tertiary
A
When organic fraction is high, secondary treatment is needed. What happens here?
A.eutrophication
B.accumulation
C.oxygen depletion
C
Tertiary treatment is needed when eutrophication happens. What wastewater fraction is intense here? A.solid fraction B.nutrients C.toxic components D.AOTA
B
How are toxic components treated? A.primary B.tertiary C.adsorption D.disinfection
C
How are non-filterable solids treated?
Coagulants are used to remove, so that neg charged ions will form flocs & become heavy
Which is false?
A.when water is turbid, organisms are deprived of solar energy and oxygen
B.increase in water depth leads to overflowing and flooding
C.fish may experience laceration due to turbid water
B - dapat reduction
Oxygen Sag Curve shows A. Which part still has DO B. How polluted water is C. How river can purify itself D. AOTA
D
How does the river recover DO?
Re-aeration –> turbulence –> unwanted gases escape –> DO again –> equilibrium
Organic decomposition yields \_\_ while inorganic decomposition yields \_\_ A.sulfur dioxide B.carbon dioxide C.methane D.ethane 2 answers
B and C
DifferentIate highly eutrophicated body of water @ daytime vs that at night. Explain mechanism also
Daytime - algae produce lotsa O2 - alkaline water
Nighttime - algae produce no O2 but lotsa CO2 - acidic water
The ff may cause fish kills except A.rapid pH change B.salinity C.temperature change D.air pressure
D
How can sewage lead to methemoglobinemia?
Urea –> ammonia –> nitrite –> nitrate
This process uses DO
Nitrate-contam water utilizes O2 @ blood
MetHbnemia!
Which is used for primary treatment of wastewater? A.activated sludge B.trickling filter C.septic tank D.disinfection house
C
Main process @ primary treatment before water displacement A.aeration B.sedimentation C.disinfection D.coagulation
B
Which is not used for primary treatment of wastewater? (Arrange remaining ones left!) A.activated sludge B.screen C.sedimentation tank D.comminutor E.scrapper
B
E
D
C
Biological reactor filled with gravel coated with slime containing microorganisms ; where is this used?
Trickling filter
Veterans Hospital
Enumerate four most common sources of wastewater
Domestic
Industrial
Storm water
Agri runoff