3. Waste Water Treatment Flashcards
What are the 3 main sources that waste water comes from?
- Household Waste (toilet, shower, disposal, kitchen sink)
- Industrial Waste (heavy metals, pharmaceuticals, radioactive)
- Stormwater (fertilizer, animal feces, motor oil)
What does a bar screen filter out?
Leaves, sticks, cans, balls
What does an aerated grit tank filter out?
Sand, gravel, coffee grounds
What is primary sludge?
The waste that floats to the bottom of the filter (ex. spaghetti)
What are skimmings?
The waste that floats to the top of the filter (ex. grease, plastic straws)
What is the primary effluent?
Nutrients dissolved in the water (ex. milk, apple juice)
How do we reduce the amount of food in the primary effluent?
Activated sludge process
Describe the activated sludge process.
Uses metabolic rxns of microorganisms to produce a high-quality effluent by converting and removing substances that have an oxygen demand
Who is the “workhouse” of the activated sludge process and what do they do?
Who: Bacteria
What: Stores their fat extracellulary, so can act as “velcro” which allows waste to stick to its receptors and taken in to be broken down
What can we infer by comparing a fat bacteria to a skinny bacteria?
Fat bacteria lacks the components needed to digest the waste (i.e. fat b/c all the waste just sticks to it and builds up)
What’s the function of protozoa found in the activated sludge?
Weighs down the bacteria flocks (which is too light on its own) and cleans up loner bacteria (i.e. those not in a group)
Are filamentous bacteria bad in activated sludge?
No, depending on their length, they provide a framework for bacterial flock to build upon
What is a pin flock?
Group of bacteria that is too light because it doesn’t have enough filaments
What does TKN represent?
TKN=Total Kjeldahl Nitrogen=Organic Nitrogen + Ammonia
Essentially, TKN=Total Potential Ammonia
Which are better at absorbing aqueous phosphorous? Aerobic or facultative bacteria?
Facultative-can absorb up to 3x more
