what is wastewater? how much wastewater do you think nyc produces per day?
TRANSCRIPT
What is wastewater?
How much wastewater do you think NYC produces per day?
What is wastewater?
1 billion gallons per day!
NYC Treatment Costs
day Mgal
dollars
TechniqueBrief Description and
Advantages vs. DisadvantagesCost
Adjusting pH
Adding acid or base to __________ water into the ______ pH range.
day Mgal
dollars
[H3O+] > [OH-] [H3O+] < [OH-][H3O+]=[OH-]
ACIDIC NEUTRAL BASIC
0 7 14
Adding H+ to make H3O+
Adding OH-
neutralize6.5-8.5
$38
Filtration
Filtration
Filtration
NYC Treatment Costs
day Mgal
dollars
TechniqueBrief Description and
Advantages vs. DisadvantagesCost
Filtration
Removes _____________ solids by
passing the water through a porous filter.
Cost due mostly to the energy used to
_________ large amounts of water. Costs
would be lower (____ less) if the solids
were not suspended (easier to separate).
day Mgal
dollars
suspended
move
2/3
$6000
Batch = one pot / flask Continuous = keep feeding water
If you have lots of
water
Distillation
NYC Treatment Costs
day Mgal
dollars
TechniqueBrief Description and
Advantages vs. DisadvantagesCost
Distillation
Removes _____________ solids (i.e. NaCl, NO3-) and bacteria. Uses large of amounts of energy for boiling and must move large amounts of cooling water or air to ___________ the purified water vapor. Requires pH & TSS pre-treatment.
day Mgal
dollars
dissolved
condense
$5700
Reverse Osmosis
Bacteria or dissolved solids
NYC Treatment Costs
day Mgal
dollars
TechniqueBrief Description and
Advantages vs. DisadvantagesCost
Reverse Osmosis
(RO)
Removes dissolved solids (i.e. NaCl, NO3-) by passing water through a semi-permeable membrane under high pressure. Requires pH and TSS pre-treatment. Though fairly cheap to build, RO plants are expensive to _________ due to the high pressures needed (energy used to ________ the water).
day Mgal
dollars
operate
pump
$5300
5 4 3 2 15/9 Wastewater Engineering
Sit with your PSA Video groups by Table #Take out 20b notes and the Wastewater
Engineering Challenge from the sink handles
1) Which two of the following four methods treat the same
type of contamination: reverse osmosis, filtering,
distillation, adjusting pH
2) If something on sale costs 1/3 less, what is the final price
if the original price was $12,000?
3) Complete the conversion:
2 ft = ???? inches
What is wastewater?
How much wastewater does NYC produce in one day?
What is wastewater?
1 billion gallons per day!(that’s 1000 swimming pools)
Today’s Challenge1st - You are a water quality engineer responsible for
cleaning 1 million gallons of wastewater per day from 800 people. Your job is to provide this service in the most sustainable way.
2nd - A salesman from Integrated Engineers tells you his product will save you a lot of money. You need to figure out if that’s true or not by testing the product.
3rd - Your goal is to write a letter to the city council evaluating the best combination of treatment options and whether you would use the product.
Engineering Challenge
PROBLEMCRITERIA
FOR SUCCESS
CONSTRAINTS
• Wastewater needs to be treated
• You need to determine the effectiveness of the Floccin™
•determine most sustainable (3E’s) treatment plan for the city
•Potable to EPA standards
• pH adjustment
• filtration
OR
• filtration with Floccin™
• distillation
OR
• reverse osmosis
Procedure & Data Collection1) Complete pre-test column of data table
2) Add Floccin to water and stir for 60 seconds
3) Complete post-test column of data table
4) Complete the Floccin Cost Calculation
Floccin Cost Analysis: Calculate how much it would cost
the city to use the Floccin product daily. The city needs to
treat 1,000,000 gal per day. Every gallon of contaminated
water requires about 2 g of Floccin. Every 1 g of Floccin
costs $0.00025. Use conversion factors. …
Calculate Floccin Cost
day
$_______
TDS
Evaluating Treatment Options
How do we decide what makes one
treatment method better than another?
What evidence do I need to know in
order to advise the city council?
How do Engineers weigh all of the pros
and cons when making decisions?
Evaluating Treatment Options
38 6000 570011,738
0
Recommendation to NYC Council Use your results to evaluate the effectiveness of the Floccin Recommend the most sustainable wastewater treatment plan from among the following techniques: pH adjustment, distillation, reverse osmosis, and filtration with or without floccin) Defend your recommendation using analysis of Economic Impact (cost) and Environmental impacts. You should refer back to engineering ideas (handout ___ ) and relevant water chemistry19
Flocculants
• Flocculants are long polymer molecules• The molecules stick to the solids in the dirty water
to make high density flocs or aggregates