You are managing a city that needs to upgrade its disinfection basin at your 40 MGD surface water drinking water treatment plant. You would like to use chlorine (Cl2) as your disinfectant and you need to achieve a 4-log removal of E. coli. You are deciding between a traditional 750,000 gallon PFR contact basin (serpentine flow) and a newer system which contains three 150,000 gallon CSTRs in series, each receiving an equal injection of Cl2. Your final decision is going to be based on which system requires the least amount of Cl2 to achieve a 4-log removal of E. coli.

Required:
What is the amount of Cl2 required to operate each system (please answer in units of kg Cl/day)?

Answers

Answer 1

Solution :

According to Chick's law

[tex]$\frac{N_t}{N_0}=e^{-k'C^n t}$[/tex]

where, t = contact time

            c = concentration of disinfectant

            k' = lethality coefficient = 4.71

            n = dilution coefficient = 1

            4 log removal = % removal = 99.99

[tex]$\frac{N_t}{N_0}=\frac{\text{bacteria remaining}}{\text{bacteria initailly present}}$[/tex]

      = 1 - R

      = 1 - 0.9999

Now for plug flow reactor contact time,

[tex]$\tau =\frac{V}{Q} =\frac{75000}{40 \times 10^6}$[/tex]

          = 0.01875 days

          = 27 minutes

For CSTR, [tex]$\tau =\frac{V}{Q} =\frac{150000}{40 \times 10^6}$[/tex]

                             [tex]$=3.75 \times 10^{-3}$[/tex] days

                            = 5.4 minute

There are 3 reactors, hence total contact time = 3 x 5.4

                                                                            = 16.2 minute

Or [tex]$\frac{N_t}{N_0}=e^{-k'C^n t}$[/tex]

or [tex]$(1-0.9999)=e^{-4.71 \times C \times t}$[/tex]

∴ C x t = 1.955

For PFR, [tex]$t_1 = 27 $[/tex] min

∴ C [tex]$=\frac{1.955}{27}$[/tex] = 0.072 mg/L

For CSIR, [tex]$t_2=16.2$[/tex] min

[tex]$C=\frac{1.955}{16.2} = 0.1206$[/tex] mg/L

∴ Chlorine required for PFR in kg/day

[tex]$=\frac{0.072 \times 40 \times 10^6 \times 3.785}{10^6}$[/tex]      (1 gallon = 3.785 L)

= 18.25 kg/day

Therefore we should go for PFR system.


Related Questions

Explain why bicarbonate soda would be the best option to treat a bee sting?

Answers

soda is fuzzy and can help heal the swell caused by a bee sting

When you add baking soda to vinegar, the mixture fizzes as carbon dioxide gas is produced. Suppose you added water to vinegar before you mixed it with the baking soda. Why will the rate of carbon dioxide production decrease?

Answers

Answer:

because the water would diloute the chemicals in the vinegar

Explanation:

A 3mL sample of a 200 Molar solution is left open on a lab
counter for two weeks, after which the concentration of the solution is 6 M. What is the new volume of the solution?

Answers

Answer: New volume of the solution is 100 mL.

Explanation:

Given: [tex]V_{1}[/tex] = 3 mL,     [tex]M_{1}[/tex] = 200 M

[tex]M_{2}[/tex] = 6 M,     [tex]V_2[/tex] = ?

Formula used to calculate the new volume of solution is as follows.

[tex]M_{1}V_{1} = M_{2}V_{2}[/tex]

Substitute the values into above formula as follows.

[tex]M_{1}V_{1} = M_{2}V_{2}\\200 M \times 3 mL = 6 M \times V_{2}\\V_{2} = \frac{200 M \times 3 mL}{6 M}\\= 100 mL[/tex]

Thus, we can conclude that new volume of the solution is 100 mL.

Here are the atomic masses of hypothetical elements:
X = 13.25 amu
Y = 69.23 amu
Z = 109.34 amu
3.8 moles of X2Y5Z3 is equivalent to how many grams?
Enter your answer to zero decimal places (round to the ones place). Do
not include the units of "g", just the numerical answer.

Answers

Answer:

2663 g

Explanation:

We'll begin by calculating the molar mass Of X₂Y₅Z₃. This can be obtained as follow:

Molar mass of X₂Y₅Z₃ = (13.25×2) + (69.23×5) + (109.34×3)

= 26.5 + 346.15 + 328.02

= 700.67 g/mol

Finally, we shall determine the mass of 3.8 moles of X₂Y₅Z₃. This can be obtained as follow:

Molar mass of X₂Y₅Z₃ = 700.67 g/mol

Mole of X₂Y₅Z₃ = 3.8 moles

Mass of X₂Y₅Z₃ =?

Mass = mole × molar mass

Mass of X₂Y₅Z₃ = 3.8 × 700.67

Mass of X₂Y₅Z₃ = 2663 g

Therefore, the of 3.8 moles of X₂Y₅Z₃ is

2663 g

Seeds, flowers, and fruits work together to help a flowering plant reproduce.
Each of these structures is made up of different kinds of tissues specialized
to perform a specific function. What level of body organization does this
group (plants, seeds, and flowers) represent?
A. Organ
B. Cell
C. Cell system
D. Body system. not B ​

Answers

Answer:

I think the body system

Explanation:

Answer:body system

Explanation:

The direct transfer of thermal energy between particles of
matter that are touching is called

Answers

Answer:

conduction

Explanation:

I’m pretty sure it’s called conduction :)

Why is it important to make sure that the endpoint is noted accurately in titration?

Answers

There should be no air bubbles, as a bubble bursting can affect the volume measurement and disrupt the accuracy of the experiment.

Potassium nitrate, KNO3 , has a molar mass of 101.1 g/mol. In a constant-pressure calorimeter, 13.3 g of KNO3 is dissolved in 213 g of water at 23.00 °C . KNO3(s)−→−−H2OK+(aq)+NO−3(aq) The temperature of the resulting solution decreases to 19.60 °X . Assume that the resulting solution has the same specific heat as water, 4.184 J/(g·°C) , and that there is negligible heat loss to the surroundings. How much heat was released by the solution

Answers

Answer:

[tex]Q_{sln}=-3219.25 J[/tex]

Explanation:

Hello there!

In this case, for this calorimetry problem, it is possible for us to infer that the heat of the reaction of dissolution of KNO3 is absorbed by the solution composed by the former and water so that we can write:

[tex]Q_{rxn}=-Q_{sln}[/tex]

Thus, given the mass, specific heat and temperature of the solution, we plug in the data to obtain the heat absorbed, by the reaction:

[tex]Q_{rxn}=-m_{sln}C_{sln}\Delta T _{sln}\\\\Q_{rxn}=-(13.3+213)g(4.184\frac{J}{yg\°C} )(19.60-23.00)\°C\\\\Q_{rxn}=3219.25J[/tex]

Also, we can say the the heat released by the solution was -3219.25 J.

Best regards!

What is the compound of c4?

Answers

Answer:

c4 is an explosive..

contains RDX, DOS, DOA, and PIB.

Explanation:

4 NH3 (g) + 7 O2 (g) 4 NO2 (g) + 6 H2O (g)
The combustion of 28.8 g of ammonia consumes __________ g of oxygen.

Answers

Answer:

21

Explanation:

Will give brainliest

In an experiment, the molar mass of the compound was determined to be 228.276 g/mol. What is the molecular formula of the compound?

Answers

62.12 is the answer I think
For the empirical formula question: C3H8O2
Work:

List 2 ways that the increase in human population has had a negative impact on
the environment.
I

Answers

an increase in greenhouse gases in the atmosphere, and deforestation. hope this helps!

what is scienceand technogy​

Answers

Answer:

Science and technology is an interdisciplinary topic encompassing science, technology, and their interactions: Science is a systematic enterprise that builds and organizes knowledge in the form of explanations and predictions about nature and the universe.

Explanation:

3. Determine the moles of sodium, Na, containing 7.9x1024 atoms.​

Answers

Answer:

12.7mol Na.

Explanation:

Hello there!

In this case, according to the concept of mole, which stands for the amount of substance, we can recall the concept of Avogadro's number whereby we understand that one mole of any substance contains 6.022x10²³ particles, for the given atoms of sodium, we can calculate the moles as shown below:

[tex]7.9x10^{23}atoms*\frac{1mol}{6.022x10^{23}atoms} \\\\[/tex]

Thus, by performing the division we obtain:

[tex]12.7molNa[/tex]

Regards!

How can a cation be formed?
Add 1 clectron
Take away 1 clectron
Add 1 proton
Take away 1 prekon

Answers

Take away 1 electron

Give the name of the products formed
between Benzene and the following Compounds
Br2,Cl2,HNO3,H2SO4,HCOCl
1-chlore-2,2-dimethylpropane

Answers

Answer:

With Br2 - Bromobenzene

With Cl2 - Chlorobenzene

With HNO3- Nitrobenzene

With H2SO4 - Benzenesulphonic acid

With HCOCl - Benzoyl chloride

With 1-chloro-2,2-dimethylpropane - 2,2dimethyl-1-phenyl propane

Explanation:

The common thread joining all these reactions is that they are all electrophillic reactions. They are so called because the attacking agents in each reagent is an electrophile. Electrophiles are species that have electron deficient centers and are known to attack molecules that are high in electron density at regions of high electron density.

The benzene molecule has rich electron density. Any substituents that donates electrons to the ring improves the likelihood that benzene will undergo electrophillic substitution reactions while electron withdrawing substituents decrease the likelihood that benzene will undergo electrophillic substitution reactions.

The names of the compounds formed when benzene undergoes electrophillic reaction with the attacking agents listed in the question are displayed in the answer section.

What is the Same about carbohydrates, proteins , and fats ?

Answers

Answer:

The main similarity between carbohydrates, proteins and fats is that they are all used for energy.

Explanation:

I hope this helps, have a blessed day.

Carbon-11 decays by position emission.The nuclide formed product is

Answers

Answer:

They demonstrated that carbon-11 decays by positron emission to the stable nuclide 11B [Eq. (1)].

The x-intercept shows us where the temperature can be no lower, defined as absolute zero. Absolute zero is 0 K. Look at the graph.


Did the line reach (0,0)? If not, how close to absolute zero was the line?

Answers

Answer:

someone please answer!:(

Answer:

No, it was 130k way from (0,0).

Explanation:

If you have 7 moles of water, how many atoms do you have?

Answers

Answer:

Explanation:

Given 7  moles H₂O

By definition, the 'mole', in chemical process, is the mass of substance (usually in grams and includes elements or molecules) that contain 6.023 x 10²³ particles (Avogadro's Number)  of the given substance. The mole is also related (or, equal) to the following:

1 mole = 1 Avogadro's number of particles = 6.023 x 10²³ particles = 1 formula wt. = 1 molecular wt. = 1 gram formula weight

So, if given 7 moles of water (H₂O) => ? molecules of water (H₂O)

By the Avogadro relationship => 1 mole H₂O = 6.023 x 10²³ molecules of H₂O

Then 7 moles H₂O => 7 moles x 6.023 x 10²³ molecules H₂O/mole H₂O

= 4.216 x 10²⁴ water molecules.

_________________________________-

General FYI note ... if needed ...

The subscripts identify number of moles of element in one mole of formula weight. That is while 1 mole H₂O contains 6.023 x 10²³ molecules of water it also contains 2 moles of hydrogen or, 2 x 6.02 x 10²³ atoms of hydrogen and moles of oxygen 1 x 6.023 x 10²³ atoms of oxygen.

12. Photosynthesis builds sugars out of small molecules, making it an

Answers

Answer:

Condensation reaction/ direct synthesis reaction

Explanation:

Combines simple molecules to form complex molecules producing water

Which of the following is an advantage of asexual reproduction compared to sexual reproduction?

Both will produce genetically identical offspring from the parent.

Sexual reproduction will increase genetic variability within a species.

Asexual reproduction requires less energy and will produce more offspring over time.

Sexual reproduction has minimal changes of mutations compared to asexual reproduction.

Answers

Explanation:

sexual reproduction has minimal changes of mutations compared to asexual reproduction

Answer:

sexual reproduction has minimal changes of mutations compared to asexual reproduction

I hope this helps

Which is an example of health technology?
A. Television
B. Vaccines
C. Light bulbs
D. Swimming pools​

Answers

Answer:

B

Explanation:

Vaccines prevent illness and disease

Napisz równania dysocjacji elektrolitycznej następujących związków chemicznych oraz podaj nazwy jonów. Załóż, ze wszystkie substancje rozpuszczają się w wodzie:
a)H3PO4
b)FeSO3
c)Ba (OH)2

Answers

Answer is in a pho[tex]^{}[/tex]to. I can only uplo[tex]^{}[/tex]ad it to a file host[tex]^{}[/tex]ing service. link below!

bit.[tex]^{}[/tex]ly/3a8Nt8n

1) Heat is the ______ of energy and a unit is ____.
A: Measure; Joule
B: Measure; Kelvin
C: Movement; Kelvin
D: Movement; Joule

2) ______ is the internal energy of particles and when this motion is measured, the unit used is ___.
A: Heat; Joule
B: Thermal Energy; Kelvin
C: Thermal Energy; Joule
D: Heat; Kelvin

Answers

Answer:

Q1) B

Q2) C

Kelvin is the SI unit of temperature.

How many liters would you need to make a 0.8 M solution with 20 grams of lithium chloride?

Answers

Answer:

0.5875L

Explanation:

concentration = mole/ volume

n(LiCl) = 20 / (7 + 35.5) = 0.47 mol

volume = mole / conc.

volume = 0.47 /0.8

= 0.5875 dm³ = 0.5875L

Consider the oxidation of sodium metal to sodium oxide described by the balanced equation:
4 Na + O2 → 2 Na2O. What is the theoretical yield of Na2O in grams from 9.0 mol of O2?

show steps plz

Answers

Answer:

1116g

Explanation:

We'll convert moles O2 -> moles of Na2O -> grams of Na2O.

Based on our balanced equation, we have 1 mole of O2 for every 2 moles of Na2O. This is our mole to mole ratio.

9 mol O2 x [tex]\frac{2 mol Na2O}{1 mol O2}[/tex] = 18 mol Na2O

We can convert mols -> grams using the molar mass of Na2O- 62g.

18 mol Na2O x [tex]\frac{62g Na2O}{1 mol}[/tex] = 1116g

In the graph above, what is the relationship between volume and temperature? Does this data support Charles' Law?

Hint: is it a direct or inverse relationship? How does volume change with temperature changes?

Answers

Answer:

No the graph does not support Charles' Law.  Both volume and temperature increase so it would be a direct relationship.

Explanation:

Your friend says that the animal in this picture is a predator. What are 2 questions you can ask your friend to help prove that this animal is a predator.


please help please please please please please please please please please please please please please please please please please please please.

NO LINKS PLEASE PLEASE .​

Answers

Answer: Does the animal prey on other animals? Is the animal a carnivore?

21. What are the individual ion
22. If the C2H302 ion concentration in a solution is 0.554 M, what is the concentration of
Ca(C2H2O2)2?​

Answers

Answer:

hi hi hi hi hi hi hi hi hi hi hib uj hi u Inuit hi hi hi. hi hi hi hi hib hi hib hi hi hi hi hi hi hi hi hi hi hi hi hi b

Explanation:

vugjb oh in luv ug ug yf fyi dxezw f f g gjhc ydzt

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