Enviro Exam 2 Learning Objectives

Front 1

3 pathogenic microorganisms

Back 1

Giardia Lamblia, causes nasuea, diarreaha, headaches

Legionella, causes a type of pneumonia if aerosolized and then inhaled

Barium, increase in blood pressure

Front 2

5 reasons why coliforms are an important indicator organism

Back 2

-Hardy
-digestive tracts resemble those of warm blooded animals
-Easily Identifiable
-Plentiful
-generally harmless

Front 3

Major points of the Safe Drinking Water Act of 1974

Back 3

-set national health‐based standards for drinking water to protect against both naturally‐occurring and man‐made contaminants that may be found in drinking water.
-Oversee all states, localities, and water suppliers who implement these standards

Front 4

New treatment requirements that came from Surface Water Treatment Rule

Back 4

The rule requires that water systems filter and disinfect water from surface water sources to reduce the occurrence of unsafe levels of Legionella and Giardia lamblia

Front 5

National Primary Drinking Water Standards vs. National Secondary Drinking Water Standards

Back 5

-Primary standards protect public health by limiting the levels of contaminants in drinking water. ENFORCABLE
-Secondary standards are non‐enforceable guidelines regulating contaminants that may cause cosmetic effects or aesthetic effects in drinking water.NOT ENFORCABLE

Front 6

MCL vs MCLG

Back 6

MCL - Highest concentration of a contaminant that is allowed in drinking water. ENFORCABLE
MCLG - Concentration of a contaminant in drinking water below which there is no known or expected risk to health. NOT ENFORCABLE

Front 7

3 ways U.S. EPA drinking water standards have evolved over time

Back 7

recognizing source water protection
operator training,
limiting byproducts

Front 8

purpose and process of coagulation and flocculation

Back 8

coagulation, chemical alters colloidal particles to make them stick together forming larger particles called flocs

flocculation, paddle stirs water causing flocs to travel at different velocities and make them stick together

Front 9

particle settling velocity vs critical veloctiy vs horizontal velocity for a gravity settling tank, which particles are removed from the settling tank

Back 9

Particle settling velocity = Vs
- Settling velocity of a particular particle (vertical direction)
Critical Velocity = Vo
- Critical settling velocity (vertical direction)
Horizontal Velocity
- particle velocity (horizontal direction)

Front 10

Explain the effect particle size has on settling velocity

Back 10

the larger the particle size the slower the settling velocity

Front 11

Process and Importance of backwashing with regards to a rapid sand filter

Back 11

volume of water through the sand filter lessens as it becomes more clogged and becomes an operational issue
-The rush of water upward expands the sand layer and
loosens the suspended solids captured on the sand
-A cross current is introduced above the sand to direct the loosened particles and wash water to a side drain

Front 12

Process and Importance of harrowing with regards to a slow sand filter

Back 12

To remove the particulate matter caught on the filter sand particles
 -Similar to plowing a field
 -A cross current is introduced above the sand to
direct the loosened particles and wash water to a side drain
-8 hrs

Front 13

rapid sand filter vs slow sand filter

Back 13

rapid sand filter is layered, smaller, more expensive, and quicker, coagulation and flocculation. newer

slow sand filter has a larger, thicker bed and is a slower process, no coagulation or flocculation. older

Front 14

4 types of membrane filters and uses for each

Back 14

Nanofiltration- water softening
Ultrafiltration- removes viruses
Microfiltration- removes bacteria
Reverse Osmosis- desalinization

Front 15

Common chemicals used in water disinfection

Back 15

Chlorine-leaves a residual that must be tested throughout the service area. Normally the residual is tested before water mains are tested

Front 16

Importance of Heterotrophic plate count (HPC)

Back 16

measures the qaulity of water to count how many heterotrophic bacteria colonies there are since other more harmful pathogens could be present. No EPA standards for HPC count. High HPC count means alot of organic content is still in the water.

Front 17

Pros vs Cons of flouride

Back 17

Cons
-Dose cannot be controlled
-only chemical added to water for the purpose of medical treatment.
Pros
-reduces the incidence of cavities

Front 18

Functions of an elevated water storage tank

Back 18

-Provide emergency storage
-Provide even supply to customers
-helps to maintain a constant pressure in distribution system

Front 19

different flow streams in 'wastewater'

Back 19

Domestic wastewater - sewage (anything can fit down pipe)
Commercial Wastewater
Inflow/Infiltration

Front 20

the process of collecting and delivering wastewater to a treatment plant

Back 20

Sanitary Sewers
Combined Sewers
Storm Drains
Inflow/Infiltration
Industrial wastewater

Front 21

inflow vs infiltration

Back 21

Inflow - Storm water that enters the sanitary sewer unintentionally
Infiltration - Groundwater that seeps into piping through cracks or small holes

Front 22

I/I effect on wastewater collection

Back 22

Significantly increases the amount of wastewater that flows through the plant along with increasing the amount of suspended solids in the water

Front 23

water quality sampling types

Back 23

Grab sample
-One sampling point at one moment in time
Composite Sample
-Multiple Grab samples combined together
Flow-weighted composite sample
-Taking multiple grab samples so that the volume of each sample is proportional to the flow at that time

Front 24

BOD testing procedure

Back 24

Calculate Dilution Factor
If seeding seed bottle
fill water up to top no air bubbles
put in fridge 20C for 5 days make sure it stays dark
subtracts IDO-FDO

Front 25

BOD5 vs BODult vs COD tests

Back 25

BOD5 - 5 day bio. oxygen demand test
BODult - streams or rivers with travel time greater then 5 days (20 days)
COD - short BOD test using chemicals results are higher then BOD

Front 26

preliminary wastewater treatment

Back 26

Removes large solids that could damage or wear down machinery
Bar Rack
Comminutor
Grit chamber
- sand and grit settles to bottom
- aerated grit chamber

Front 27

primary wastewater treatment

Back 27

Settling Tank
-v-notch weirs
-sludge settles to bottom

Front 28

secondary wastewater treatment

Back 28

Remove biochemical oxygen demand (BOD)
1. Trickling Filter
- filter bed of rocks less than 4 inches wide water trickles over
- Active biological growth forms on the rocks
- Air circulates by force or temperature
- Underdrain system
2. Activated Sludge
-Aeration tank
- mix sludge, influent water, and oxygen together
-Final settling tank, or final clarifier
- Separate the activated microorganisms from the mixed liquor
-liquid effluent flows over a v‐notch weir
-Return activated sludge
 -Settled (and hungry) microorganisms are pumped to the head of the aeration tank
-Wast activated sludge
-sludge thats thrown away

Front 29

tertiary wastewater treatment

Back 29

Rapid sand filters
Oxidation Ponds
Activated Carbon absorption
Nitrogen Removal
Phosphorus Removal

Front 30

trickling filter vs activated sludge system for secondary treatment

Back 30

trickling filter is simple and low maintenence but usually water is cycled over the rock bed multiple times

sludge system is slow but effective and requires alot more energy to introduce oxygen into aeration tank

Front 31

when an extended aeration wastewater treatment system would be utilized?

Back 31

High degree of treatment
Isolated sources
-Hotels, small communities
Little or no waste activated sludge

Front 32

purpose of tertiary wastewater

Back 32

When secondary treatment is inadequate to protect the receiving waters from harm due to the wastewater discharge.
 Nitrogen
 Phosphorus
 Total organic carbon 
Metals
 Industrial wastes

Front 33

density of water

Back 33

1 kg/L