instruction manual for environmental engineering DAVIS

8/10/2019 instruction manual for environmental engineering DAVIS

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INSTRUCTORS MANUAL

TO

ACCOMPANY

INTRODUCTION

TOENVIRONMENTAL ENGINEERING

4THEDITION

Mackenzie L. DavisMichigan State University

With

Geneva M. Hulslander

Michigan State University

WCB/McGraw-HillDubuque, IA


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TABLE OF CONTENTS

Introduction....................................................................................................iii

Errata..............................................................................................................iv

Pedagogical Thoughts....................................................................................v

Sample Course Outline ..................................................................................vii

Sample Exams................................................................................................ix

Solutions to End of Chapter Problems...........................................................1-1


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INTRODUCTION

This manual provides solutions for all of the end of chapter problems and discussion

questions inIntroduction to Environmental Engineering. In typing the solutions, errors in

the problem statements have come to light. Errata for these statements are included in this

manual. We encourage instructors to review problems before they are assigned to ensurethat all the data and assumptions are clear. McGraw-Hill will post other errata as they are

brought to our attention.

I have provided some pedagogical remarks on the organization of the text as well as

suggestions for use of the pedagogical aids. These include suggestions for use of end ofchapter review items and discussion questions.

A sample course outline and sample exams follow the pedagogical remarks. The course

outline has been used in a 3 credit (3 lectures per week in a semester format) sophomoreintroductory course taught to a class of about 120 students. Approximately one-third of

the students are civil engineering majors. The remainder come from a variety ofdisciplines including but not limited to chemical engineers, mechanical engineers,electrical engineers, computer science and engineering majors, chemistry, crop and soil

science, and resource development. The average grade for the class is 2.7 on a 4.0 scale.

We appreciate any comments, corrections, and suggestions. Please address them to me at:

Mackenzie L. Davis, Ph.D., P.E., DEE

Department of Civil and Environmental Engineering3546 Engineering Building

Michigan State University

East Lansing, MI48824

I may also be reached by e-mail at [email protected]. Please put Intro. to ENE in thesubject line so that my filters dont delete your message.


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ERRATA

CHAPTER 10

Page 832, Example 10-2. Revise sentence that begins He has taken a long

shower to read He has taken a 12 minute showerAlso, the total at the end of the example that reads:

CDT= 1.04 x 10-4

+ 1.04 x 10-4

+ = 1.60 x 10-4mg/kg-d

Should read

CDT= 1.24 x 10-4+ 1.04 x 10-4+

= 1.80 x 10-4

mg/kg-d

Page 837. Example 10-3. Because of the error in Example 10-2, there is an error in

Eample 10-3. The risk equation should read:

Risk = (1.80 x 10-4mg/kg-d)(1.5 x 10-2(mg/kg-d)-1)

= 2.70 x 10-6

And the total lifetime risk should be 75 years not 70 years.

Page 907, Problem 10-4. Replace the sentence: Assume a 1-year averaging time.

To: Assume both the child and the adult have an equivalent exposure of 1 day per weekfor 20 weeks in a year and that the fraction of 2,4-D ingested is 0.10.

Page 907, Problem 10-6. There is a conflict between the ages specified for the child.Change the second assumption: Assume her average age over the exposure period is 8.

To: Assume the averaging time is 5 years.


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v

PEDAGOGICAL THOUGHTS

The selection of material and arrangement of the text chapters is based on my experience

in teaching introductory environmental engineering for over 30 years, and my desire to

introduce beginning engineering students to the many facets of environmental

engineering. I do not cover all of the material in the text in a semester. As may be seen inthe sample course outline, I have used, perhaps, 600 pages of the text material in the

introductory course. Other portions of the text are used in two senior level design coursesthat are supplemented with a very large course pack. The material on laws, legislation

and ionizing radiation are provided for completeness and with the recognition that this

book will be one of those that engineering students begin to accumulate for theirprofessional library.

I begin with materials and energy balance because it is a useful tool environmental

engineers can use to solve problems and because it is a useful tool that instructors can useto explain environmental phenomena. It is also useful from a teaching point of view

because it reminds the student that the math courses they are taking have directapplication to solving engineering problems. The hydrology chapter is introduced next asa matter of pedagogy. First, water is a fundamental part of 2/3 of the material in the book.

Second, rainfall, runoff, etc. are physical concepts that students can relate to in their lifes

experience. Third, it provides simple examples of mass balance that students canvisualize. Fourth, for those colleges and universities that do not offer a hydrology course,

it provides the civil engineering students that focus on other specialization areas of civil

engineering, such as transportation, the basics they need. It may be argued that

hydrology is covered in another course. This is a fallacious argument: chemistry iscertainly covered in another course, yet many environmental engineering instructors

insist that a stand alone chemistry chapter be included in introductory texts. In fact, my

other introductory text bows to this wishand yet, civil engineering students are turnedoff by another chemistry course. So a lead-off chapter focused on chemistry often is a

turn-off chapter on environmental engineering. This is contrary to my desire to interest

and invite students to explore environmental engineering in more advanced courses.Chemistry is introduced in the 4thchapter. This is far enough into the course material for

the students to get a feel of my lecture style and the different emphasis in engineering in

contrast to the basic sciences and math they have been previously exposed to.

With, perhaps, the exception of the noise chapter, the remaining chapters that I cover in

the introductory course are fairly standard. The reason for covering noise in the

introductory course is two fold. First, those civil engineers that are not going to specializein environmental engineering will find that the projects they work on most often impact

the public because they are noisy. This is particularly true in the transportation area.

Second, while there are many courses and seminars that are available to explore waterand wastewater treatment, air pollution, solid waste management, and hazardous waste

management, the opportunities for civil and environmental engineers to gain a basic

understanding of the environmental impact of noise and its control are rare.


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vi

Pedagogical aids

There are numerous aids for the student in the text. In my first lecture, I invite the

students to bring their textbooks to the second lecture. In the second lecture I spend a fewminutes introducing them to the book. I invite them to look at the inside of the front and

back cover as well as the appendices. In particular I point out the review items at the endof the chapter. In my lecture style, I introduce the lecture with a list of the review items

that I will cover during the lecture. For examination review, I identify those items that I

have covered that will be on the exam. I construct my exam from the review items. Notall review items are examined every year because there are too many for one exam. But

for each course offering they are all discussed.

The review items also have been extremely useful in fulfilling the ABET requirement forexplicitly stating course objectives and evaluating student achievement in meeting the

course objectives.

The other pedagogical aid is the list of discussion questions. The questions are designed

to stimulate thinking about the subject rather than simply crunching numbers. Most of

them are derived from questions that students or the public have asked me! They arethings students who have had an introductory environmental engineering course are

expected to know without having a book. I have used them in a variety of ways. One use

is to pose one of the discussion questions at the beginning of the lecture in which they are

covered. Then, at the end of lecture ask the students to write a short answer that I collectto evaluate their comprehension. I have also used them as part of an examination review.

Another use is to pose them as a closed book examination question. I have never assigned

them as homework.

Instructional aids

Not included in this manual, but available for qualified instructors, is a set of Power Point

slides and a set of jpeg figures for each chapter. Contact your McGraw-Hill

representative to learn how to access these aids.


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SAMPLE COURSE OUTLINE

Date Lecture Topic Reading Assignment

AUG 24 Introduction 1-5

27 Mass Balance 42-6129 Water Resource Systems 5-11

SEP 1 HOLIDAY

3 Hydrology Fundamentals 98-106

5 Rainfall Analysis 107-112

8 Runoff Analysis/Rational Method 113-119

10 Runoff Analysis/Unit Hydrograph 119-124

12 Runoff Analysis Problem Session

15 Storage of Reservoirs 129-133and REVIEW FOR EXAM 117 EXAM 1

19 Groundwater Hydraulics and

Prediction of Drawdown 133-149

22 Properties of Aquifers andWell Interference 149-155

24 Prediction of Drawdown Problem Session26 Prediction of Drawdown Problem Session

29 Water Chemistry and 188-207and Water Quality 213-227

OCT 1 Treatment Systems and Coagulation 227-235

3 Definition of Hardness & Softening 235-247

6 Softening Problem Session8 Softening Problem Session

10 Sedimentation and Filtration 271-278, 283-286

13 REVIEW FOR EXAM 214 EXAM 217 Water Quality Management/Rivers 354-365, 368-391

20 Water Quality Management/Rivers Problem Session22 Water Quality Management/Lakes 391-400

24 Wastewater Treatment Alternatives and

Pretreatment and Primary Treatment 426-443, 447-449

27 Wastewater Microbiology 449-459


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29 Activated Sludge 459-471

31 Activated Sludge Problem Session

NOV 3 AWT and Sludge Treat. & Disposal 493-497, 500-501, 522

5 REVIEW FOR EXAM 3

6 EXAM 3

10 Air Pollution Chemistry, Effects & Fate 548-56712 Air Pollution Meteorology 580-588

14 Dispersion of Air Pollutants 589-597

17 Air Pollution Control 601-633

19 Fundamentals of Acoustics and 653-665

Effects on People 665-680

21 Airborne Transmission of Noise 690-699

24 Traffic Noise Prediction 699-70926 Noise Pollution Control 709-72328 HOLIDAY

DEC 1 Solid Waste Collection & Disposal 737-749, 762-769, 787-7963 REVIEW FOR EXAM 44 EXAM 4


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SAMPLE EXAM 1

(Closed Book)(100 points)

(If a true false question is false, you must provide a non-trivial correction to make it true to receive full credit.)

1. (12) The time period for a unit hydrograph is equal to the duration of the excessrainfall.

TRUE FALSE

Answer: True

2. (12) What major element(s) of the hydrologic cycle is (are) missing from thefollowing list?

1. Ground water Flow 2. Evaporation

3. Transpiration 4. Precipitation

Answer: Surface runoff, Surface water body

3. (12) The time of concentration is particular to the given geometry and surfacecomposition of watershed regardless of the intensity of the rainfall.

TRUE FALSE

Answer: True

4. (12) What type of water treatment plant is normally used for a ground watersupply?

Answer: Softening or iron removal

5. (12) The units for the rational formula are: Q = m3/s, C = no units, I = mm/h, A =ha

TRUE FALSE

Answer: True

6. (16) Sketch an artesian aquifer with a flowing artesian well. Identify aquiclude,confining layer, recharge area, and piezometric surface.

Answer: See Figure 3-3


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SAMPLE EXAM 1

(Open Book)(50 points)

(Failure to state units on final answer will result in an automatic reduction of one point.)

1. (25) Apply the unit hydrograph distribution to the following observed rainfall.Compute the compound runoff. Show all work.

Day Rain [cm] Abstactions [cm] UH Ord. [m3/s-cm]

1 0.80 0.80 0.46

2 0.50 0.00 0.23

3 0.00 0.00 0.31

2. (10) Compute the first two duration values for an I-D-F curve for an 8 year stormfrom the following 86 year record. Show all work.

Duration [min]

1.00 1.25 1.50

50.00 25.00 17.00 6.00

60.00 16.00 9.00 3.00

80.00 7.00 4.00 2.00

No. Times = Stated Intensity [mm/h]

3. (15) Determine the size reservoir (in m3) for the following monthly flows:

Month Inflow [m3/s] Discharge [m

3/s]

Aug 1.98 2.00

Sep 1.95 2.00

Oct 3.09 2.00


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SAMPLE EXAM 2

(Closed Book)(100 points)


1. (16) Write the equation(s) for removal of hardness caused by Mg when nobicarbonate is available using lime or lime and soda ash as required.

Answer: ( ) ( ) ( )++ ++ 2

s22

2 CaOHMgOHCaMg

++ ++ Na2CaCOCONaCa )S(3322

2. (12) What percent of particles having a vsof 0.25 cm/s will be removed in anupflow clarifier if v0is 0.50 cm/s?

Answer: = scm25.0vS scm5.0v0 = Therefore 0.0% removed.

3. (12) The bacillus group of microorganisms is used as an indicator of watercontamination.

TRUE FALSE

Answer: False. Should be colliform group.

4. (12) Sketch the pumping curve which shows the interception of a barrier by the

piezometric surface at a drawdown of 10 m after 15,000 minutes of pumping.Label the axes and point of interception. Draw the curve from 1.0 minutes to100,000 minutes. (Use a separate piece of paper.)


5. (12) Sketch the effects of increasing valence on colloid charge reduction. Labelthe axes and curves. (Use a separate piece of paper).


6. (12) Define palatable as it pertains to drinking water.

Answer: Palatable means that it tastes good. It is not necessarily safe to drink.

7. (12) Define alkalinity in terms of its chemical components.

Answer: Alkalinity = [HCO3-] + 2[CO3

2-] + [OH

-] [H

+]


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SAMPLE EXAM 2(Open Book)

(50 Points)

(Failure to state units on final answer will result in an automatic reduction of one point.)

1. (15) What amount of lime and/or soda ash, in mg/L as CaCO3, is required tosoften the following water to 80.0 mg/L hardness as CaCO3? Show all work.

CompoundConcentration

[mg/L as CaCO3]

CO2 21.3

Ca2+ 103.0

Mg2+ 137.0

HCO3- 329.8

SO42- 158.8

2. (20) If a fully penetrating well in a 30.00 m thick artesian aquifer pumping at arate of 0.0180 m3.s for 1863 days causes a drawdown of 5.25 m at an observation

well 45.45 m from the pumping well, how much drawdown will occur at an

observation well 90.90 m away? The original piezometric surface was 50.12 mabove the bottom confining layer. The aquifer material is fractured rock. Show

all work. Report answer to two decimal places.

3. (15) Calculate the sedimentation tank surface area whose loading is 12.00 m3/d-m2for a flowrate of 0.0400 m3/s. Find the detention time (in hours) if the depth

of the tank is 3.00 m. Show all work.


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SAMPLE EXAM 2 SOLUTIONS TO OPEN BOOK QUESTIONS

1. TH = 240 mg/L as CaCO3CH = 240 mg/L as CaCO3because CH may not exceed total even though HCO3is

greater

NCH = 0.0

Lime Additions:

Lime = CO2 = 21.3

Lime = HCO3 = 329.8Lime = Mg 40 = 97

Excess = 40Total = 488.1 mg/L as CaCO3

Soda Ash:

Since there is no NCH to be removed, add no soda ash.

2. This is a confined aquifer at steady state conditions.

h1= 50.13 5.25 = 44.88

Find K from Table = 5.8 x 10-5

T = KD = (5.8 x 10-5)(30.00) = 0.0017

( )

( )0017.0245.4590.90ln0180.0

88.44h 2

=

h2= 1.166 + 44.88 = 46.05

The drawdown is then s = 50.13 46.05 = 4.08 m

3. From the definition of overflow rate

( )( ) 223

3

0

S m0.288mdm00.12

ds400,86sm0400.0

v

QA ===

From the definition of detention time

( )( )s600,21

sm0400.0

m0.3m0.288

Q

Vt

3

2

=== or 360 min or 6 h


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SAMPLE EXAM 3(Closed Book)

(100 points)


1. (15) Sketch a graph showing BOD as a function of time for rate constants of 0.37and 0.15 d-1if the ultimate BOD is 450 mg/L. Label the axes, coordinates of

ultimate BOD, the curve(s), and the ultimate BOD. (Use a separate piece of

paper.)


2. (9) List three locations for the ultimate disposal of sewage sludge.

Answer: Land spreading, Landfilling, Dedicated land disposal

3. (12) Briefly describe aerobic decomposition in terms of electron acceptor used,important end products, odor potential, place in the natural ecosystem, and role in

wastewater treatment.

Answer:

a. Electron acceptor = O2

b. Important end products = CO2, H2O, new cells

c. Odor potential = low

d. Natural ecosystem = healthy streams

e. Role in wastewater treatment = dilute waste

4. (12) List three reasons why NH3 is detrimental to rivers, streams, and lakes.

Answer:

a. Toxic to fish

b. Exerts oxygen demand

c. Stimulates algal growth (algae die and exert BOD)

5. (8) Explain the effect of operating at a low F/M ratio on oxygen requirement andsludge production.

Answer:

a. High oxygen requirementb. Low sludge production

6. (8) Sketch and label the parts of a trickling filter wastewater treatment plant. (Usea separate piece of paper.)



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7. (12) Complete the following list of basic alternatives for treating municipalwastewater: activated sludge, tricking filter, ,

Answer: rotating biological contactor, lagoon

8. (12) List the phases of bacterial growth.

Answer

a. Lag phase

b. Accelerated growth

c. Log growth

d. Stationary

e. Death

9. (12) Choose the best answer by placing the letter from the left column in bracketsin the right column. Letters may be used only once. All letters do not necessarily

have a corresponding bracket.

A. Raise pH Phosphorous removal ( )

B. FeCl3 Activated Carbon ( )

C. Refractory organics BOD5 ( )D. Na2CO3 NH3removal ( )

Answer: Phosphorous removal = B, Activated Carbon = C, BOD5= none, NH3

removal = A


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1. Density conversion:

1000g1000

kg1

m

L1000

L

cm1000

cm

g

3

3

3

=

For example

( )( ) 3s mkg680,1100068.1 ==

Viscosity is obtained from Appendix A at 10oC (note footnote to table)

= 1.307 x 10-3

( )( )( )

m109.2100016808.9

0238.010307.118d 45.0

3

=

=

2. BODt= (DOb,t DOs,t)(DF)

183 = 6.1(DF)

DF = 30.0

Sample size = %33.30.30

%100

DF

%100==

3. Note: Problem is in base 10

BOD5= L(1 10-Kt)

226 = 305(1 10-5K)

( )5K101305

226 =

-0.259 = -10-K(5)

Canceling the signs and taking the log of both sides

log(0.259) = log(10-K(5))

-0.5867 = -K(5)

K = 0.117 d-1


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4. Convert ultimate BOD to mg/L. NOTE that ultimate BOD after mixing = La.This is a problem of converting mass discharge to concentration.

( )( )( )( )( )

Lmg23.6mL10ds86400sm60.2

kgmg10dkg1400L

333

6

a ==

Since the deficit after mixing is zero, Da= 0.0 mg/L

Convert time to days

d5196.0dh24

h47.12=

NOTE: Ks are capitalized, therefore in base 10.

( )( ) ( )( ) ( )( )( ) 0.0101007.113.4 23.607.1D5196.013.45196.007.1 +=

D = 0.5899

From Table, DOS= 8.83 mg/L at 22oC

DO = 8.83 0.5899 = 8.24 or 8.2 mg/L


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SAMPLE EXAM 4(Closed Book)

(100 points)


1. (3) Which one of the following is one of the seven major air pollutants designatedby the EPA?

a. CO2 b. Cl2 c. N2 d. MOX e. NOX f. Ca

Answer: e. NOX

2. (10) List the four physiological/psychological effects of noise other than hearingdamage.

Answer:

a. Speech interferenceb. Annoyance

c. sleep interference

d. Performance degradation

e. Privacy

3. (10) Complete the list of four potential chronic health effects caused by airpollution.

1. Chronic bronchitis 2. Bronchial asthma

Answer: 3. Pulmonary emphysema 4. Cancer

4. (6) A ppm is used to measure which of the following:

a. Concentration of gaseous pollutantb. Size of particulates

c. Concentration of particulate air pollutants

Answer: a. Concentration of gaseous pollutant

5. (10) Sketch the A weighted network response curve of a Type 2 sound level

meter. Label the axes and indicate representative values on the axes.


6. (10) Which of the following air pollution control devices is most appropriate forcontrolling metal fume emissions?

a. Bag house b. Venturi c. Packed tower


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Answer: b. Venturi

7. (6) which of the following is a common feature of an air pollution episode?

a. Unstable atmosphere b. Large source c. Early recognition

Answer: b. Large source

8. (10) Which of the following most accurately describes the theoretical basis of theoperation of a venture?

1. Mass transfer of gas to liquid

2. Mass transfer of gas to solid

3. Centrifugal force moves particles to wall4. Screening and inertial impaction

5. Impingement of water droplet6. Ions attach to particles

Answer: 5. Impingement of water droplet

9. (8) A land breeze is the result of a more rapid cooling of the land surface than thewater surface.

TRUE FALSE

Answer: True

10.(7) Sound pressure level is defined as follows:

SPL = 20 log(p/po)

TRUE FALSE

Answer: True

11.(10) Given the following vertical temperature profile, compute the lapse rate andgive the stability of the atmosphere. Show all work.

Z [m] T [oC]

2.00 5.00

50.00 4.52

Answer: mC0100.000.200.50

00.552.4

Z

T=

=

or -1.00oC/100m

Stability = Neutral


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12.(10) Match the following by placing the letter from the left column in the mostappropriate bracket in the right column. Each letter may be used only once and

all brackets may not be appropriate.

A. Continuous noise Electric saw ( )

B. Intermittent noise Air conditioner ( )C. Impulse noise Alarm clock ( )

Answer: Electric saw = B, Air conditioner = A, Alarm clock = none


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1. NOTE: GWM of NO2= 46, T2= 18 + 273 = 291

( )( )( )

=

925.100325.101

273291414.22

GMW1000ppm

V

M

a

P

( )( )( )3.249

925.100

325.101

273

291414.22

46100013.0

V

M

a

P =

= or 250 g/m3

2. Stability class = B

Check xL

sz= 0.47(280 85) = 91.6

From Figure 7-23 xL= 0.85 km and 2xL= 1.7 km

Since calculation is to be made for 5 km downwind, use Equation 7-25

( )( )( )( )33 mg1035.1

2800.46402

2424 =

=

3. The attenuation by air absorption is calculated directly from Table 8-8 with adistance of 100 m.

( ) dB3.2kmm1000

m100kmdB23A 1e =

=

Calculate the ground attenuation

The source zone = 30hs= 30(1.2 m) = 36 m

Because ground is hard, G = 0

From Table 8-9, As= (1-G) 1.5, so As= (1-0) 1.5 = -0.5 dB

The receiver zone = 30 hr= 30(1.2 m) = 36 m

Because ground is hard, G = 0

From Table 8-9, As= (1-G) 1.5, so As= (1-0) 1.5 = -0.5 dB


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The middle zone = 100 36 36 = 28 m

Because the ground is hard, G = 0

The value of e is

( )28.0

100

721

r

hh301e rs =

=

+

Am= -3(0.28)(1 0) = -0.84

The ground attenuation is then

Ae2= -0.5-0.5-0.84 = -1.84

With the basic point source model

Lp= 92 20 log (100) 11 2.3 (-0.84) = 39.5 or 40 dB at 4,000 Hz

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instruction manual for environmental engineering DAVIS