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CEE 370 Lecture #1 9/9/2015
Lecture #1 Dave Reckhow 1
David Reckhow CEE 370 L#1 1
CEE 370Environmental Engineering
Principles
Lecture #1Introduction I
Reading: Chapter 1 in Mihelcic & Zimmerman
Updated: 9 September 2015 Print version
Introduction to Environmental Engineering
CEE-370Lecture 1
Presented by: Rassil and Julie
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Introduction to CEE 370
Syllabus
Environmental Engineering
The application of science and engineering principles: To care for and/or restore our natural environment
To solve environmental problems associated with human activities
Impacts everyone and everything Plants
Insects
Animals
Humans
Ecosystems
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The Big Picture Human overpopulation (~7,363,183,400)
Resource use (land, water, fossil fuels, crops, meat…)
Intensive farming Higher meat production and crop farming
Increased irrigation
Nutrient pollution
Land use Desertification
Habitat change
Land pollution
Hydrology Distribution of water resources
Quality of water resources
Challenges:• Fresh water supply• Running out of oil• Climate change• Mounting of solid
waste
Main Umbrellas - Air
Air pollution
Acid rain
Greenhouse gases
CO
Particulate matter
O3 at the ground level
Pb
Nitrogen oxides
Sulfur oxides
Indoor air quality
CO
Radon
Mold and moisture
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Main Umbrellas - Land
Land/soil quality Heave metals: Pb
Insecticides
Pesticides
Fertilizers
Petrols, oils, solvents etc..
Ash
Main Umbrellas – Drinking Water
Water quality Surface water
Ground water Microorganisms (Fecal and total coliform, Legionella, Giardia
lamblia, cryptosporidium, viruses, turbidity)
Disinfection by-products (Haloacetic acids, trihalomethanes, bromate, chlorite, others)
Inorganic chemicals and metals (As, Pb, F, Chromium, nitrates, nitrites, Cd, Asbestos…)
Organic chemicals (dioxin, PCBs, toluene, vinyl chloride… )
Radionuclides (radium, uranium…)
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Cycling of Mercury
(http://www.mfe.govt.nz/publications/waste/mercury-inventory-new-zealand-2008/2-mercury-environment)
Common Environmental Engineering Terms
Pollution prevention At source rather than at end-of-pipe
Sustainable engineering
Water/wastewater treatment technology
Environmental remediation Contaminant removal from environmental media
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Some Basic Rules
mass(g)=MW (g/mol) x n (Moles) Example: What is the number of moles of KCl (MW=74.45
g/mol) in 74.45 g of KCl?
n=mass/MW=0.07445/74.45= 0.001 mol
Molar concentration: Ci (mol/L)=ni (mol) / Volume (L) In 1 L of water: Ci=0.001/1=0.001 mol/L
Mass concentration: Ci (g/L)=massi (g) / Volume (L) In 1 L of water: Ci=0.001 g/L
Some Basic Rules
Dilution: C1V1=C2V2
Example: You have a 12.0 M solution of hydrochloric acid (HCl) and your experiment requires 150.0 mL of 8.0 M HCl. How much water and how much 12.0 M HCl should you use to make 150.0 mL of 8.0 M HCl?
How much HCl?
12V1= 8*150
V1= 8*150/12= 100 mL of HCl
How much water?
150-100=50 mL of water
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Mass Balance
Conservation of mass to account for “material” entering and leaving a system to analyze physical systems
1. Define you control volume
2. Choose the material of interest
3. Consider all possible sources (inputs) and sinks (exports)
Typical mass balance
Evaporation Precipitation
Sediment BottomAlgae
Surface water
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Basic Questions
What is the “stuff ”? Identify the species of interest
How much “stuff ” is there? Concentration Concentration: the “amount” of a substance per “amount” of
media Common forms (assuming constant pressure):
Mass balances of substance A in air:
CA=MassA / VolumeAir
Chemical reactions of substance A in air:
[A]=MolesA / VolumeAir
Basic Questions
How fast is the “stuff ” entering and exiting a specified volume? Flow rate or Q Flow rate: the volume of fluid that passes through a given
media per unit time
Q (L3/T)= Volume / time = Area * velocity
If we have 10 gallons of tap water in 10 minutes:
Q=10 gal/10 min=1 gal/min
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Typical mass balance
Example: N
Accumulation= Σimports – Σexports + Σsources – Σsinks
=ΣCinQin-ΣCoutQout+S-kVC
Evaporation Precipitation
Sediment BottomAlgae
Surface water
Qin
Cin
Qout
Cout
Lab Session #1
Objective: To measure volumetric flow rate (Q) and mean velocity (v) of a small stream
Three methods: Floating markers
Tracer-dilution
Mechanical current meters
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Floating Markers Method
A measure of the time it takes for an object to float a specified distance downstream, or a measure surface velocity (vsurface)
Eq. 1,2
Eq. 3
Eq. 4
Tracer-Dilution Method(Instantaneous)
A measure of the downstream concentration of a tracer (known volume and concentration) discharged/injected instantaneously (sudden/slug) upstream over time until the concentration reaches the background level.
Calculating the discharge from the slug injection method involves integration, or calculating the area under the curve of concentration vs. time
Tra
cer
conc
entr
atio
n (C
)
Time (t)
Area
Cb
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Mechanical Current Meters Method
Swoffer meter: Based on stream velocity at a specific point (depth and width) for a specified time frame (in seconds).
0.6D 0.2D
0.8D
Lab Session #1
Today: Make groups of 4. Read and understand the lab session handout for next week’s lab exercise for
all three methods.
Day of: Expect to step into the stream (knee-depth at most) so wear appropriate
clothing (flip-flops, shorts). Bring a notebook to record your data and take notes. Leave on time to reach Groff Park by 2:25 PM If you don’t know the directions and/or need a ride, talk to your TA.
Write-up Prepare a write up (1 per group) as per technical report handout and the lab
handout (last couple of pages) Turn in your write-up at the beginning of the following lab session. You have a two-week period instead of the traditional one-week period.
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Next To next lecture
Reading for next class:
M&Z: Chapter 1 Hardin’s “Tragedy of the Commons” Science, 13 Dec
1968 (pg 1243)
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