Micro Biology For Exam 3

Front 1

2 Reasons for
Water Treatment (sewage)

Back 1

1. Prevent disease transmission
2. Reduce amount of organics

Front 2

What happens if aquatic microbes use aerobic respiration?

Back 2

The water becomes aerobic (almost no dissolved oxygen) which means death by suffocation of fish & shelfish

Front 3

What is produced by anaerobic microbes that use fermentation or anaerobic respiration?

Back 3

Smelly gases

Front 4

_________ is a sulfate reducing bacteria that produces SO4 to _____ by aerobic respiration (to get a rotten egg smell).

Back 4

Desulfovibrio & H2S

Front 5

_________ Treatment: physically separates "biosolids" from dissolved & suspended organics.

Back 5

Primary

Front 6

In Primary Treatment, how much of the organics can be removed?

Back 6

30-40%

Front 7

What does Secondary Treatment do?

Back 7

Treats water from Primary Treatment

Front 8

What are the 2 goals of Secondary Treatment?

Back 8

Goal 1: Rapid conversion of organic carbon to CO2 gas
Goal 2: Reduce pathogens

Front 9

What does Secondary Treatment rely on in converting organic carbon to CO2 gas?

Back 9

It relies on microbes to do aerobic respiration which turns the organics/sugars/etc into CO2

Front 10

For the rapid conversion of organic carbon to CO2 in Secondary Treatment to be successful, we need lots of _______ to reduce organics by _______ in a few hours.

Back 10

oxygen & 90-95%

Front 11

It's possible that the microbes (in Secondary Treatment) can sometimes be killed. This means that the organics cannot get decomposed. What is an example a microbe-killing substance?

Back 11

Toxic Chemicals (ex:// too much disinfectant flushed down a toilet)

Front 12

In Secondary Treatment, how do we get oxygen to the microbes? (2 ways)

Back 12

1. Activated Sludge Tanks which use injections of compressed air
2. Use of a Trickling Filter

Front 13

Describe a Trickling Filter

Back 13

Water is sprayed from rotating arms (booms) and then flows over a deep bed of rocks (traditionally), as it trickles on the rocks, it picks up oxygen and microbes will colonize on the rocks using slime layers and then they break down organics aerobically

Front 14

In Secondary Treatment, the reduction of pathogens occurs where?

Back 14

In the Activated Sludge Tank and Trickling Filter

Front 15

What are the 3 ways of reducing pathogens in Secondary Treatment?

Back 15

1. Flocculation
2. Predation
3. Competition

Front 16

Describe Flocculation

Back 16

Organic balls of goo & microbes (sticky balls) "floc" like biosolids; they sink to the bottom removing pathogens from water

Front 17

Describe Predation

Back 17

Preying on other microbes- especially protozoans, they prey on bacteria