LIS Quiz 1 Review

What are the steps of Hypoxia?1. Excess fertilizer is sprayed on hundreds of residential lawns.2. Rain or runoff (CSO) brings nitrogen to rivers, then the

Sound.3. Excess nitrogen in the water causes an algae bloom.4. The algae die in a short time and settles to the bottom of the

water.5. Bacteria decompose the dead algae using more oxygen as

they multiply.6. Dissolved oxygen levels become very low.7. Fish leave and other less mobile animals weaken and die.8. The animals that died from low oxygen levels decompose.

Decomposers use more oxygen & the problem of low oxygen becomes worse.

Coliform

• Bacteria found in sewage and human waste

Combined Sewer Overflow (CSO)

• Release of untreated sewage & street runoff due to heavy rain

Nonpoint Source

• Pollution you can not identify the specific source

Pathogen

• Microorganisms that cause illness and disease

Point Source

• Pollution you can easily identify and know the specific source

Pollutant

• Anything in the air, water, or earth that is harmful

Primary Sewage Treatment

• Process that removes solids from wastewater.

Pycnocline

• Boundary between colder, saltier water at the bottom and warmer, less salty water on the surface – oxygen can’t cross

Sanitary Sewers

• Sewers carrying human waste

Secondary Sewage Treatment

• Process that removes organic matter from sewage

Sewage

• Water carrying waste - wastewater

Sewer Systems

• Complex of pipes and pumps carrying wastewater to sewage treatment plants

Storm Sewers

• Sewers carrying road and parking lot runoff

Wastewater Treatment Events

1. Plant Influent through sanitary sewers2. Bar Screens3. Primary Clarifiers4. Biological Reactors (bacteria)5. Secondary Clarifiers6. UV Disinfection7. Clean Effluent Discharge

Plant Influent

• Water that comes from sanitary sewers and enters the plant

Bar Screens

• Remove items larger than 0.75 inches – so the pipes do not get clogged

Primary Clarifiers

• Removes about 50% of solids/sludge

Biological Reactors

• Microorganisms digest sewage

UV Disinfection

• After this process pathogens can no longer reproduce

Solids Processing

• Solids are dewatered

You should be able to…

1. Explain the difference between aerobic and anaerobic bacteria.

2. Identify which type of bacteria is used in a septic tank and which type is used at a waste water treatment plant and explain why.

3. Discuss the difference between the combined sewage system and the modern system.

4. Provide reasons why the modern system is better5. To go above and beyond – mention problems that a

modern system could have (news article)