Which fact below is NOT one of FoolProof's 4 "Web Facts"?

A process engineer performed jar tests for a water in order to determine the optimal pH and dose using alum. A test was conducte

IRINA_888 [86]

Answer:

1) 13 mg/liters

2) 72.22 mg/lit

3) The Alkanity in raw water is not sufficient enough and the kinds of chemicals needed to enhance its acidity are

CaO
KOH
Na2CO3
NaOH
CO2
NaHCO3

Explanation:

1) plot of turbidity versus dose and optimal dose of Alum ( mg/L )

Optimal dose of Alum = 13 mg/liters from the graph attached below

2) Theoretical amount of alkalinity consumed at the optimal dose can be calculated as follows

Alkanity is due to $HCO^-_{3}$

given optimal dose of Alum = 13 mg/liters for question 1

I mole of alum = 2 moles of AL(OH)3

666 grams of alum = 2*27 = 54 grams of AL(OH)3

hence 1 mole of $AL^{+3}$ = (13/54 ) mMole / lit

The moles of HCO3 = 6 * $\frac{13}{54}$ because 1 mole of Alum reacts with 6 moles of HC03

[HCO3] as CaCO3 = 6 * (13/54) * 50

= 72.22 mg/lit (theoretical amount of alkalinity consumed)

3) The Alkanity in raw water is not sufficient enough and the kinds of chemicals needed to enhance its acidity are

CaO
KOH
Na2CO3
NaOH
CO2
NaHCO3

3 0

3 years ago

In water and wastewater treatment processes a filtration device may be used to remove water from the sludge formed by a precipit

PtichkaEL [24]

Answer:

The volume of sludge after filtration is 0.914 m

Explanation:

Solution

Given that:

We have to find the Volume of sludge after filtration

Now,

The Sludge concentration is = 32%,

The sludge volume = 100 m,

The sludge concentration after filtration = 35%

Then,

The mass balance equation is stated below

Cin∀in = Cout∀out

Now,

We Solve for ∀out

∀out =Cin∀in/Cout

By substituting the values

∀out = (0.32)(100 m)/(0.35) = 0.914 m

6 0

3 years ago

If you are in a tornado situation, which of the following actions would put you in danger?

anzhelika [568]

Answer: Going outside to film it, not taking cover, trying to run away from the tornado, driving away, etc.

Please mark as brainliest

4 0

3 years ago

Which of the following is most likely to require changes to existing zoning laws?

oksano4ka [1.4K]

Answer:

Adaptive reuse

thats it thankyou

8 0

3 years ago

1. A cylindrical casting is 0.3 m in diameter and 0.5 m in length. Another casting has the same metal is rectangular in cross-se

Lorico [155]

Based on the Chvorinov's rule, the diference in the solidification times of the two castings is 14.092 times the solidification time of the prism casting.

<h3>How to apply the Chvorinov's rule for casting processes</h3>

The Chvorinov's rule is an empirical method to estimate the cooling time of a casting in terms of a reference time. This rule states that cooling time (t) is directly proportional to the square of the volume (V), in cubic meters, divided to the surface area (A), in square meters. Now we proceed to model each casting:

<h3>Cylindrical casting</h3>

t = C · [0.25π · D² · L/(0.5π · D² + π · D · L)]²

t = C · [0.25 · D · L/(0.5 · D + L)]² (1)

<h3>Prism casting</h3>

t' = C · [3 · T² · L/(6 · T · L + 2 · T · L + 6 · T²)]²

t' = C · [3 · T · L/(8 · L + 6 · T)]² (2)

<h3>Relationship between the cross sections of both castings</h3>

3 · T² = 0.25π · D² (3)

Where:

t - Cooling time of the cylindrical casting, in time unit.
t' - Cooling time of the prism casting, in time unit.
C - Cooling factor, in time unit per square meter.
D - Diameter of the cylinder, in meters.
L - Length of the casting, in meters.
T - Width of the cross section of the prism casting, in meters.

If we know that D = 0.3 m, then the thickness of the prism casting is:

$T = \sqrt{\frac{\pi}{12} }\cdot D$

T ≈ 0.153 m

And (1) and (2) simplified into these forms:

<h3>Cylindrical casting</h3>

t = C · {0.25π · (0.3 m) · (0.5 m)/[0.5 · (0.3 m) + 0.5 m]}²

t = 0.0329 · C (1b)

<h3>Prism casting</h3>

t' = C · {3 · (0.153 m) · (0.5 m)/[8 · (0.5 m) + 6 · (0.153 m)]}²

t' = 0.00218 · C (2b)

Lastly we find the percentual difference in the solidification times of the two castings by using the following expression:

r = (1 - t'/t) × 100 %

r = (1 - 0.00218/0.0329) × 100 %

r = 93.374 %

The cooling time of the prism casting is 6.626 % of the solidification time of the cylindrical casting. The diference in the solidification times of the two castings is 14.092 times the solidification time of the prism casting. $\blacksquare$

To learn more on solidification times, we kindly invite to check this verified question: brainly.com/question/13536247

3 0

3 years ago