1. Water POllution

2. BOD: What is it? Biodegradable organic matter
Excess is consumed by bacteria in the water
They deplete the water of oxygen
Example: Gold fish bowl

3. What causes a buildup of BOD
Fall leaves
Animal/human waste discharge
Process plant discharge-especially in food manufacturing

4. Conditions that can cause elevated levels
Water temperature increases causing the bacterial population to increase
If sufficient organic material is present in the water

5. How can you measure it
Chemists mix water with “organics” with oxygen and test how long it takes for the oxygen levels to drop
This test is typically 5 days at a lab
COD testing is another route
Much more cost effective
Quicker results
Can be done in house

6. March 2016: Florida Fish KIll

7. What is El Nino? Climate cycle begins in the Pacific Ocean
Warm water from the western tropical Pacific ocean shifts eastward along the equator of South America
Forcastors declare an official El Nino when they see both ocean temperature and rainfall veer towards the east
Happens every 3-5 years

8. El nino
Super El Nino
Hottest summer yet ( warmest summers)
Sea surface temperatures peak around December, impact is usually seen a few months later as the global ocean heats up
2015 hottest year ever without El Nino, but El Nino caused a 8-10% increase in temps as well

9. El Nino Causing massive algae bloom
Pseudo-nitzschia genus produces a deadly neurotoxin
Builds up in sediment and sea-life
Warm water in the Pacific (The Blob) combined with nutrient rich water of Pacific coast=perfect conditions
Duration of algae blood precedented

10. Algae Bloom COmplications
Fish kills
Amnesic shellfish poisoning
GI issues
Vomiting and diarrhea after ingestion
Must be monitored and communicated in the summer during blooms
Dungeness crab/clamming

11. Hormone Disruptors and Drugs
Pulp mills release estrogen-like compounds in significant amounts into lakes and rivers
Changes the hormonal system of the animals that ingest them
When fish are exposed to these hormones, male fish develop both male and female reproductive parts
Female birth control pills

12. Hormone Disruptors and Drugs
Paper mills release group of potentially harmful materials know as dioxins
High levels are carcinogenic
Low levels will suppress the immune systems of animals/humans
Some have converted to chlorine free processes, but very little have converted thus far

13. Sewage Treatment and Disposal
Primary sewage treatment
Secondary sewage treatment
Tertiary treatment

14. Primary Sewage Treatment
Settling tanks (Clarifiers)
Removes solids from water/fluid chlorinated and discharged
Travel through screens when it enters the plant
Sludge is pumped to the digester
Bacteria feed on it
Methane gas is produced-can be burned off
Primary treatment removes 30-60% BOD

15. Secondary Treatment
Aerobic bacteria to break down degradable organic materials
Removes ammonia to nitrates
Activated Sludge Process
Trickling Filter

16. Activated Sludge Process
Fluid is pumped out of the clarifier into another tank that is aerated
Aerobic bacteria breakdown
BOD drops rapidly due to increase oxygen and aerobic bacteria
Then transferred to settling tank
Remaining suspended material and bacteria sink to the bottom

17. Sludge digester Sludge is transferred to the anaerobic digester
It is broken down to activated sludge due to the lack of oxygen
Some is recycled back to aeration tank to seed the tank
What is left is dried and can be used as a fertilizer or go to the landfill

18. Trickling Filter
Sewage is sprayed by arms that are slowly rotating onto a filter bed of stones
Stones are covered with thin film to help dissolve organic compounds
Solids are transferred to sludge tank
80-85% of dissolved organics are removed

19. Tertiary Treatment Removes nitrates and phosphates
Not all waste water systems have tertiary treatments
Four times as expensive to operate
Currently 50% of treatment plants have tertiary treatment

20. Recycling Waste Fuel Livestock feed Soil fertilizer
Biogas used to run sewage
Livestock feed
Proteins and fats that are required
Soil fertilizer
Land apply