class 1 Flashcards
What is better than alum because of the broader ph range?
Iron Salts (ferric)
What chemical is used for pretreatment of a facility containing metals?
Magnesium Hydroxide
What is used to control struvite build up on anerobic digesters?
Ferric Chloride
Has a rotten smell
mercaptans
What should be the minimum depth of a clarifier?
7 to 10ft
What type of microscope for filamentous organisms
phase contrast at 1000x power
What type of program is used for SBR
programmable logic controllers
What two things are happening if chlorine demand of plant increases?
Nitrite is present and incomplete nitrification
Mesophilic Temperature range
85-100 F
Thermophilic Temperature range
131-140 F
What are mudballs?
Material, round in shape that form in filters and gradually increase when not removed from backwash
What is log growth phase
Is the inital stage of bacterial growth. Is ample food supply and bacteria grow at maxium rate
What disease can be transmitted thru wastewater
Hepatis A and hepatis B
What is the most common disease to be transmitted thru wastewater?
Hepatitis A
What is the most cost effective way of aeration
low speed turbine
Explosive limit for gasoline
1.2 LEL / 7.1 UEL
Explosive limit for methane
5 LEL / 15 UEL
BOD seeding
2.0 mg/l minimium DO depletion and at least 1.0 mg/l Residual DO
3 facts of filamentous organisms
- Nocardia SSP true branching is observed.
- Main cause of dirty brown foam is short filament
- Sphaerotilus natans are false branching is frequently observed(long filament)
What should the DO in anoxic zone be
Less than .5 mg/l
Sulfure dioxide is
acute toxic and corrosive
Reverse osmosis filters only allow ?
water to pass, retaining salts and higher molecular weight components
Chlorine oxidant dosage for packed bed wet scrub.
2-4 moles of cl2 per mole of H2s
Sodium hydroxide dosage for packed wet bed scrubber
2-4 moles of NAOH
Sodium hypochlorite dosage for packed wet bed scrubbers
2-4 moles of NAOCL
Hydrogen Peroxide dosage for packed wet bed scrubbers
3-8 moles of h202
What are 4 problems that cause cavitation
- Having pump at too high of distance above fluid
- having too long of distance of suction pipe
- pump should operate near rated head
- flow rates higher than designed flow
What can cold temperature do to MCRT
the colder the temperature the longer the MCRT needed to produce a nitrified effluent
Flagellates predominance indicate?
high f/m ration and low MCRT
Ciliates predominance indicate?
Process is approaching stable operations
Stalked ciliates predominance indicate?
Stable process that produces low turbidity effluent
rotifiers predominance indicate?
Old activated sludge with high MCRT
Suctoria predominance indicate?
Old sludge high MCRT
