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

. A bar of copper has a mass of 216g and a volume of 24cm3. What is the density of copper?

Answers

the answer is 9g/cm3

Which organisms in soil helps relieve element so they can be recycled

Answers

Answer:

Bacteria are also involved in many processes that are indispensable for our life on Earth. Many of these processes have to do with the recycling (reuse) of chemical elements that have been here since the formation of the planet

Explanation:

I hope it will help you

What is the mass of an iron piece that cools from 57.8 °C to 26.4°C while releasing
7160.2 J of heat? The specific heat capacity of iron is 0.444 J/gºC.

Answers

The answer above should be correct!

Which gland would most likely have an issue with maintaining the breakdown of food?

the thyroid
the thymus
the pancreas
the ovaries

Answers

Answer:

OKAY EVERYONE STOP SAYING PANCREAS THATS WRONG

Explanation:

It is actually thyroid

A saline solution, NaCl in water, is 0.92 % (m/v). How many grams of NaCl are required to prepare 35.0 mL of this solution?

Answers

Answer:

0.322 g

Explanation:

Since our concentration is given in mass per volume percent % (m/v)

% (m/v) = mass of solute in g/volume of solution in mL × 100%

Since % (m/v) = 0.92 and volume of the required solution is 35.0 mL, we find the mass of NaCl from

mass of NaCl = % (m/v)/100 % × volume of solution

= 0.92 % (m/v)/100 %× 35 mL

= 0.0092 × 35

= 0.322 g

The study of a chemical is called chemistry.

The correct answer is 0.322 g

The saline is said that the amount of salt present in the solution. The formula used to solve the question is as follows:-

[tex]\frac{m}{v} = \frac{mass \ of\ solute}{volume\ of\ solution} * 100[/tex]

The data is given as follows:-

0.92 %(m/v)Volume is 35.0 mL,

Mass of NaCl is as follows:-

 [tex]\frac{0.92}{100} * 35 mL[/tex]

[tex]0.0092 * 35\\= 0.322 g[/tex]

Hence, the correct answer is 0.322g.

For more information, refer to the link:-

https://brainly.com/question/14698383

What is the correct definition of temperature

Answers

Answer:

i'm pretty sure its the last answer and if not its the 2nd one

WILL GIVE BRAINLIEST!!!

Answers

Answer:

The answer is B

Explanation:

The answer is B because representative particles can only be atoms.

When NH3(g) reacts with O2(g) to form N2O(g) and H2O(l) , 342 kJ of energy are evolved for each mole of NH3(g) that reacts. Write a balanced thermochemical equation for the reaction with an energy term in kJ as part of the equation. Note that the answer box for the energy term is case sensitive. Use the SMALLEST INTEGER coefficients possible and put the energy term (including the units) in the last box on the appropriate side of the equation. If a box is not needed, leave it blank.

Answers

Answer:

2 NH₃(g) + 2 O₂(g) ⇒ N₂O(g) + 3 H₂O(l)   ΔH° = -684 kJ

Explanation:

Let's consider the unbalanced equation that occurs when NH₃(g) reacts with O₂(g) to form N₂O(g) and H₂O(l).

NH₃(g) + O₂(g) ⇒ N₂O(g) + H₂O(l)

We will begin balancing N atoms by multiplying NH₃(g) by 2.

2 NH₃(g) + O₂(g) ⇒ N₂O(g) + H₂O(l)

Then, we will balance H atoms by multiplying H₂O(l) by 3.

2 NH₃(g) + O₂(g) ⇒ N₂O(g) + 3 H₂O(l)

Finally, we will get the balanced equation by multiplying O₂(g) by 2.

2 NH₃(g) + 2 O₂(g) ⇒ N₂O(g) + 3 H₂O(l)

Since 342 kJ of energy are evolved for each mole of NH₃(g), and there are 2 moles of NH₃(g) in the balanced equation, the heat evolved will be2 × 342 kJ = 684 kJ. By convention, when heat is evolved, it takes a negative sign. The balanced thermochemical equation is:

2 NH₃(g) + 2 O₂(g) ⇒ N₂O(g) + 3 H₂O(l)   ΔH° = -684 kJ

What is the total number of protons, neutrons, and electrons in a cadmium, Cd, atom that has a mass number of 112?

Record your answer and fill in the bubbles on your answer document. Be sure to use the correct place value.

Answers

Answer:

Number of Protons 48

Number of Neutrons 64

Number of Electrons 48

Explanation:

The mass number of an atom is the sum of the number of protons and neutrons in the nucleus of that atom

Diagonal relationship is present between the lighter elements of periods
1) Second, third 2) Second, fourth 3) Third, fourth
4) third, fifth

Answers

Answer: The diagonal relationship is present between the lighter elements of periods second, thirds.

Explanation:

Elements which are present diagonally adjacent to each other in the second and third periods of the periodic table tends to show diagonal relationship as they have similar properties.

For example, Lithium is a second period element and magnesium is a third period element.

Hence, lithium and magnesium show diagonal relationship with each other.

Thus, we can conclude that diagonal relationship is present between the lighter elements of periods second, thirds.

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

Help me please jus tell me 1 2 3 etc for the answers thank you!

Answers

Answer:

1. lakes and rivers 2. groundwater 3. watershed 4. pollution

Explanation:

how to get a girl
need to get a girl

Answers

Answer:

pretty easy

Explanation:

step 1: Approach her

step 2: Ask her for something (make it look like you're lost even when you aren't)

step 3: engage in a conversation with her

step 4: you talk for hours and she give you her number

step 5: you wake up from your dream

step 6: wait you woke up

step 7: go back to dreaming again.

Answer: Girls are tough. Girls are....attitude, we all know its true.

Explanation

Best thing to start is shush when shes talking.

You are performing an acid-base neutralization reaction in the laboratory to determine the concentration of an unknown base. You are supposed to titrate it with a monoprotic acid, but your lab partner accidentally fills your buret with sulfuric acid, a diprotic acid, with the same concentration as the acid called for in the experiment. How will the volume of diprotic acid compare to the volume of monoprotic acid you would have used

Answers

Answer:

Volume is reduced to half

Explanation:

Acid base titration are commonly used reactions in a lab, and are ofter used to get pH or different kind of solutions.

The neutralization of an acid base reaction is reached, when the solution (having added an indicator previously) changes its original color. chemically speaking, this occurs when the number of moles of the acid and the base are balanced and equal. In other words the following:

n₁ = n₂   (1)

This expression can also be expressed in function of concentration and volume:

M₁V₁ = M₂V₂   (2)

From here, solving for V₁:

V₁ = M₂V₂  / M₁

Now, this expression is true only when we have the same kind of substance that can lose or gain the same number of hydrogens.

Lets suppose that we have as base NaOH (Monoprotic base) and HCl (monoprotic acid), the titration reaction would be:

NaOH + HCl --------> NaCl + H₂O

As both of the species are monoprotic, the number of moles are the same  when they reach the equilibrium, so, expression  (2) can be used, and calculate volume or concentrations.

However, in this case, a partner made a mistake and use a diprotic acid, in this case, H₂SO₄, In this case, things chance because H₂SO₄ is diprotic, meaning that we need to dissociate two hydrogens in equilibrium, therefore, expression (2) would be something like this.

Acid: 1; Base: 2

H₂SO₄ + 2NaOH ------> Na₂SO₄ + H₂O

nH₂SO₄ = n₁ = 1

nNaOH = n₂ = 2

n₁/n₂ = 1/2

2n₁ = n₂   (3)

Writting this, in function of concentration and volume, it would be:

2M₁V₁ = M₂V₂   (4)

From here, if we solve for the volume of the acid (V₁):

V₁ = M₂V₂ / 2M₁

Therefore, according to this expression, we can see that the volume required of the acid would be half the volume required of the monoprotic acid. For example, if we need 50 mL of Chloridic acid to reach the equivalence point with NaOH, then, with H₂SO₄ it will only need 25 mL. This, of course, assuming that concentrations are the same, and volume of the base used, the same.

Hope this helps

please help i don’t know this:(

Answers

Answer:

29.5 days

Explanation:

orginally 27.3 days but 29.5 days is also correct

in general, what do you think a subscript in a chemical formula tells you

Answers

Answer:

In the most simplest of words: The number of atoms in a molecule

ex) c6h12o6

There are 6 carbon atoms and oxygen atoms, 12 hydrogen atoms

Another example NH4

there are 1 nitrogen atoms and 4 hydrogen atom

Hope that answers your question

Explanation:


14. A sample of carbon dioxide occupies a 2.54 dm² container at STP. What is the volume of the gas at a
pressure of 150.0 kPa and a temperature of 26.0°C?
0.180 dm
c. 2.24 dm3
b. 1.88 dm
d. 4.65 dm3

Answers

Your answer is D. Hope this helps

By using combined gas law , volume will be 1.88 [tex]dm^{3}[/tex].

What is combined gas law?

The combined gas law contains the laws of Charles, Boyle, and Gay-Lussac. When you know the pressure, volume, and temperature of a system and need to modify one of these, you can apply this law to compute the resulting unknown.

Combined gas law is expressed as:

[tex]$\frac{P_{1} V_{1}}{T_{1}}=\frac{P_{2} V_{2}}{T_{2}}$[/tex]

Calculation of volume by using combined gas law

It is given that, [tex]V_{1}[/tex] = 254[tex]dm^{3}[/tex], at STP P = 101.3 kPa and T = 273 K

Now, put the value of given data in above equation.

[tex]V_{2}[/tex] = (254[tex]dm^{3}[/tex]) (101.3 kPa) (26+273) /(150 kPa) (273)

[tex]V_{2}[/tex] = 1.88 [tex]dm^{3}[/tex].

By using combined gas law  volume will be 1.88 [tex]dm^{3}[/tex].

To know about combined gas law.

https://brainly.com/question/13154969.

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1: Write the positive and negative ions that result when the following compounds are dissolved in an aqueous solution:
Compound:
1. Na2CO3(a)
2. FeBr3(aq)
3. Al2(SO4)3(aq)

2: Write word and formula equations for the reaction of sodium hydroxide, NaOH(aq) and phosphoric acid, H3PO4(aq). Word equation_________. Formula equation________. Why does this reaction occur?

Answers

Answer:

See explanation.

Explanation:

Hello there!

In this case, for the required chemical reactions, we proceed as follows, by considering that the left-handed elements stand for the cations and the right-handed ones for the anions:

1:

1. [tex]Na_2CO_3(aq)\rightarrow 2Na^+(aq)+(CO_3)^{2-}(aq)[/tex]

2. [tex]FeBr_3(aq)\rightarrow Fe^{3+}(aq)+3Br^-(aq)[/tex]

3. [tex]Al_2(SO_4)_3(aq)\rightarrow 2Al^{3+}(aq)+3(SO_4)^{2-}(aq)[/tex]

2: In this case, we can represent the formula equation first according to the neutralization reaction:

[tex]3NaOH(aq)+H_3PO_4(aq)\rightarrow Na_3PO_4(aq)+3H_2O(l)[/tex]

Which is worded as: three molecules of aqueous sodium hydroxide reacts with one molecule of aqueous phosphoric acid to yield one molecule of aqueous sodium chloride and three molecules of liquid water.

Regards!

Jerry is trying to classify cells by their physical characteristics. He discovers a multicellular organism containing cells that have a nucleus and a cell wall as well as the ability to conduct photosynthesis. Into which of the three domains would this organism most likely fit? A. Archaea B. bacteria C. Eukarya D. Viral​

Answers

Turn on will turn on will turn on both turn on mobile

Domains eukarya  would this organism most likely fit.

The domain eukarya comprised of eukaryotes or organisms whose cells contain true nucleus.

What is a domain?

It is  the largest of all groups in the classification of life. There are three domains:-

Archaea domainBacteria domainEukarya domainWhat is Eukarya?

It is the domain of organism called eukaryotes. These are the organism who have a well defined nucleus and membrane bound organelles.

Hence, C) option is correct.

To know more about domain here

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Please answer I will give you brainliest!!

Answers

Answer:

Warm front

Explanation:

A warm front forms when a warm air mass pushes into a cooler air mass, shown in the image to the right (A). Warm fronts often bring stormy weather as the warm air mass at the surface rises above the cool air mass, making clouds and storms. Warm fronts move more slowly than cold fronts because it is more difficult for the warm air to push the cold, dense air across the Earth's surface. Warm fronts often form on the east side of low-pressure systems where warmer air from the south is pushed north.

You will often see high clouds like cirrus, cirrostratus, and middle clouds like altostratus ahead of a warm front. These clouds form in the warm air that is high above the cool air. As the front passes over an area, the clouds become lower, and rain is likely. There can be thunderstorms around the warm front if the air is unstable.

On weather maps, the surface location of a warm front is represented by a solid red line with red, filled-in semicircles along it, like in the map on the right (B). The semicircles indicate the direction that the front is moving. They are on the side of the line where the front is moving. Notice on the map that temperatures at ground level are cooler in front of the front than behind it.

Which of these space objects is the largest asteroid in the solar system?

Select one:
a. Pluto
b. Vesta
c. Ceres
d. Earth's Moon

Answers

Answer:

CERES is the latgest in the solar system

Explanation:

C ceres and you can look it up it says the same thing

Using your freshly made 5M stock aqueous solution of NaCl and your 10% aqueous stock of SDS, you find a prepackaged bottle of 1M Tris-Hcl (aqueous solution) along with a 95% solution of liquid NP-40 in a bottle. Using these stock reagents calculate the amount needed for the following final concentrations for each reagent as well as the final volume of water needed to obtain:
Total Final volume of 500 mL
Final Concentrations:
150 mM NaCl
50 mM Tris-HCl
1% NP-40 .
1% SDS

Answers

Answer:

1. Volume of stock required = 15 mL

Volume of water required = 485 mL

2. Volume of stock required = 5 mL

Volume of water required = 495 mL

3. Volume of stock required = 5.30 mL

Volume of water required = 494.70 mL

4. Volume of stock required = 50 mL

Volume of water required = 450 mL

Explanation:

Using the dilution formula C₁V₁ = C₂V₂

Where C₁ = initial concentration; C₂ = final concentration; V₁ = initial volume; V₂ = final volume

1. C₁ = 5 M NaCl, C₂ = 150 mM NaCl = 0.15 M NaCl

V₁ = ?; V₂ = 500 mL

V₁ = C₂V₂/C₁

V₁ = 0.15 × 500/ 5 = 15 mL

Volume of stock required = 15 mL

Volume of water required = 500 mL - 15 mL

Volume of water required = 485 mL

2. C₁ = 1 M Tris-HCl, C₂ = 50 mM Tris-HCl = 0.05 M Tris-HCl

V₁ = ?; V₂ = 500 mL

V₁ = C₂V₂/C₁

V₁ = 0.05 × 500/ 5 = 5 mL

Volume of stock required = 5 mL

Volume of water required = 500 mL - 5 mL

Volume of water required = 495 mL

3. C₁ = 95% NP-40, C₂ = 1% NP-40

V₁ = ?; V₂ = 500 mL

V₁ = C₂V₂/C₁

V₁ = 1 × 500/ 95 = 5.30 mL

Volume of stock required = 5.30 mL

Volume of water required = 500 mL - 5.30 mL

Volume of water required = 494.70 mL

4. C₁ = 1% SDS, C₂ = 10% SDS

V₁ = ?; V₂ = 500 mL

V₁ = C₂V₂/C₁

V₁ = 1 × 500/ 10 = 50 mL

Volume of stock required = 50 mL

Volume of water required = 500 mL - 50 mL

Volume of water required = 450 mL

what characteristics of a metallic bond explains some of the properties of metals

Answers

Answer:

See Explanation

Explanation:

Metallic bonds involve attraction between electrons and positively charged metal ions. The metals are ionized and electrons form a sea of valence electrons. These loosely bound electrons surround the nuclei of the metals.

The presence of this sea of electrons explains the fact that metals conduct electricity and heat due to the free valence electrons.

Due to the nature of the bonding between metal atoms,metals are malleable and ductile.

Due to the strong electrostatic interaction between metal ions and electrons, the metallic bond is very strong and is very difficult to break thereby accounting for the greater strength of metals as the size of the metallic ion decreases.

Help please will mark brainliest!!

Answers

Answer:

90% of people marry there 7th grade love. since u have read this, u will be told good news tonight. if u don't pass this on nine comments your worst week starts now this isn't fake. apparently if u copy and paste this on ten comments in the next ten minutes you will have the best day of your life tomorrow. you will either get kissed or asked out in the next 53 minutes someone will say i love you.

What type of muscle controls leg movement?

A. cardiac
B. striated
C. smooth

Answers

I think the answer is C

Answer:

c

Explanation:

for best accadimes

What happens to the entropy when a solution is made?
A. The entropy increases.
B. The entropy decreases.
C. The entropy goes to zero.
D. The entropy is unaffected.

Answers

Answer:

The entropy increases

Explanation:

Just took the quiz

A metal forms two oxides X and Y when contains 28.9% and 21.0% oxygen respectively.
a) calculate the ratio by mass of metal in the two oxides
b) what chemical law does it illustrate
Please help no Link please

Answers

And metal phones to Oxsee’s ex and Y1 contains 28.9%Auction and we’re actually calculate the ratio

which solution has a higher percent ionization of the acid , a .10 M solution of HC2H3O2 (aw) or a .010 M solution of HC2H3O2(aq)

Answers

Answer:

0.0010 M of HC2H302(aq)

what is a factor of a solution​

Answers

Answer:

Normality factor is defined as the ratio of observed wt. of solute to the theoretical wt. of the solute required to prepare a solution of desired normality. ... The principle states that, “the product of volume and concentration factor of the solution at any dilution is constant provided mass of the solution is constant.”

Explanation:

Which of the following has the largest mass of carbon per gram?
H₂CO₃
CH₃CO₂H
CH₃OH
CH₃CH₂OH

Answers

Answer:

ch3

Explanation:

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