1. Introduction to Environmental Engineering Dr. Kagan ERYURUK

2. Chemical concentrations in water, air and soil

3. Air Low molecular interaction Gas-phase and photochemical reactions
Ideal Gas Law
PV=nRT
Dalton’s Law of Partial Pressures
Pt = P1 + P2 + … + Pn
UNITS!
volume/volume

4. Air

5. Air
Example: If we have 133g of oxygen, 459.5g of nitrogen, and 172.2g of carbon dioxide in a box 1 m3 in volume, what would be the pressure of gas within the box? The temperature of the box is 25°C.
PV=nRT
P=(n/V)RT
Start with Oxygen
133 g O2 m3
32 g O2
mol
8.31 mol O2
8.31 mol O2 m3
mol K
Pa m3 K
PO2
PO2 20,607 Pa or kPa

6. Air Pt = P1 + P2 + … + Pn PO2 20.61 kPa PN2 40.68 kPa PCO2 9.69 kPa
Pt PO2 + PN2 + PCO kPa
Pt kPa

7. Water Strongly dipolar molecule Hydrogen bonding Units
Liquid at atmospheric pressure and room temperature (ex. H2S is heavier & gas)
Large heat capacity
Solid is less dense than liquid
Units
mass/volume

8. Water Temperature oC Takes a lot of added heat to change temperature
Absorbs or releases more heat than many substances for each degree of temperature increase or decrease
Ice
Melting
Water
Boiling
Steam
Temperature oC

10. Nitrate concentrations in water
typical U.S. surface waters: 0.2–2.0 mg/L
European Union: 50 mg/L NO3
U.S. EPA
10 mg/L NO3-N and
10 mg/L NO3 + NO2 as N
The concentration of nitrate in the Red Cedar River was found to be 31 mg/L. Would this be an acceptable source of drinking water based upon these values?
50 mg/L NO3 > 31 mg/L NO EU OK!
31 mg/L NO3 > 10 mg NO3 VIOLATES U.S. EPA

11. Soil Mixture Surface reactions Partitioning reactions Classify soils
includes water and air
Surface reactions
Partitioning reactions
Classify soils
Units
mass/mass

12. Soil Texture
Elemental composition of earth outer-surface layer

13. Classifying Soil

14. Law of Conservation of Matter
Material Balances
Law of Conservation of Matter
Matter can neither be created nor destroyed.
The mathematical representation of this law is called a materials balance or mass balance.
For environmental processes, the basic equation is:
Accumulation = Input – Output - Decay
The system could be the planet or it could be a cell or anything in between.
System boundaries are defined so as to make calculations simple. The system within the boundaries is called the control volume.

15. Control Volume: what is within the dotted lines
rain
Sapanca Lake
river
river
evaporation
Assumptions
Steady State – accumulation in the system does not change (in = out)

16. Surface area of a lake = 40 km2
Flow rate of a river which is inflow to the lake=0.56 m3/s
Flow rate of a river which is outflow from the lake=0.48 m3/s.
Precipitation amount for 1 month=45 mm
Vaporaziton amount for 1 month=105 mm
Leakage amount from the bottom of lake for 1 month=25 mm
Calculate the change in water volume into the lake after 1 month? Assume 1 month as 30 days.

17. Law of Conservation of Energy:
Energy Balances
Law of Conservation of Energy:
Energy cannot be created or destroyed. The mathematical representation of this law is called an energy balance.
Energy -- capacity for doing work
BTU, Joule, kw-hr, cal
Work -- force x displacement
Newton-m, ft-lb
Power -- rate of doing work
watt (J/s), hp, BTU/hr

18. Energy Transfer
conduction
convection
radiation

19. Conduction copper rod in flame gets hot -- conduction
normally associated with solids -- vibrational energy of hotter molecule translated to adjacent molecules. For example copper and wood stick

20. Thermal Conductivities
Material
htc (J/(s·m·ºK)
Air
0.023
Aluminum
221
Brick, fired clay
0.9
Concrete 2
Copper
393
Fiberglass insulation
0.0377
Steel, mild
45.3
Wood
0.126

21. Convection
transfer of heat from a fluid as a result of movement of the fluid and contact with another substance
examples: blood in body, coolant in auto
forced convection - pump or blower
natural convection - from density differences

22. Radiation
continual emission of radiation from the surface of all objects in the form of electromagnetic waves
objects emit EM radiation as a function of their temperature and surface area
higher T  more EM radiation  shorter 

23. Ecosystems and Nutrient Cycles
Ecology – the study of the interrelationships between plants and animals that live in a particular physical environment
Ecosystems – communities of organisms that interact with one another and their physical environment
Habitats – places where a populations of organisms live

24. Human Influences on Ecosystems
We normally separate non-human (natural) aspects of ecosystems from human (anthropogenic) influences
Many ways to describe perturbations
chemical − biological − physical
land use − pollution − global
Response may be complex due to the interrelationships

25. Role of Energy in Ecosystems
Primary source of energy that drives ecosystems is the sun
Process starts with primary producers that convert inorganic carbon into organic compounds that store energy
Photosynthesis
6CO2 + 6H2O + energy → C6H12O6 + 6O2
Stored energy can then be recovered in the “reverse” reaction, respiration
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
Release energy is available to drive other reactions, e.g. cell metabolism and growth

26. Basic Trophic Levels Autotrophs 1 Herbivores 2 (chemotrophs)
Carnivores
(chemotrophs) 3

27. Food Webs

28. Bioaccumulation
Many organic compounds are highly hydrophobic (water hating)
Hydrophobic compounds partition to other phases, such as the plankton, in aquatic systems
The partition coefficient is the equilibrium constant for reaction

29. Biomagnification
When partitioning concentrates a chemical in one phase that is the food for a higher phase, the chemical can further concentrate as we move up the food chain

30. Biomagnification
While partitioning is primarily a chemical process, biomagnification is a complex biological process
Biomagnification factors are empirical

31. Example
Hexachlorobenzene (HCB) has a water to plankton partition coefficient of 200,000; a plankton to smelt magnification factor of 7.5; and a smelt to lake trout magification factor of If the concentration of HCB in the water is 1.0 ppt will either fish exceed the fish consumption standards:
5 ppm for general consumption
1 ppm for pregnant and nursing women

32. Solution

33. Carbon Cycle

34. Carbon Cycle
Inputs of “new” CO2 comes naturally from minerals and anthropogenically from the combustion of fossil fuels
Plants are responsible for most of the CO2 that is converted to organic carbon
Carbon is lost to deep ocean zone via the solubility and biological pumps
Carbon cycles within the biosphere by photosynthesis and respiration

35. Nitrogen Cycle

36. Nitrogen Cycle Atmosphere provides an abundant reservoir of N2
N2 is converted to biologically available forms naturally by nitrogen-fixing organisms and anthropogenically by combustion
Nitrogen cycles between NO3-, NO2-,NH3, and organic N by different organism
N2 is returned to atmosphere by denitrification under anaerobic conditions

37. Phosphorus Cycle

38. Phosphorus Cycle Inputs from mineral weathering and fertilizer use
Biological cycling between phosphates and organic P
Losses through precipitation and burial in sediments

39. Sulfur Cycle

40. Sulfur Cycle Natural inputs from minerals
Anthropogenic inputs from fossil fuel combustion, mining, and metal processing
Biological cycling elemental S, sulfides, sulfates, organic S
Chemical cycling via precipitation and volatilization
Losses through precipitation