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