Introduction to Environmental Engineering Dr. Kagan ERYURUK

2 Overview of Environmental Policy, Law, and Regulation

3 How does the quality of our surroundings affect 1 our physical health? 2 the health of other species and the ecosystem itself? 3 our economic well-being? 4 future generations?

Indoor air quality Water quality Food source and quality Electromagnetic field exposure (EMF) Sights and sounds 4

5 Common Environmental Values 1. no adverse affect on our personal health 2. minimal or no affect on public health 3. worthwhile to protect species and natural environments 4. consider both the costs and benefits of environmental protection efforts

6 Do you know …. EPA (Environmental Protection Agency) EPA (Environmental Protection Agency) Ministry of Environment and Urban Development Ministry of Environment and Urban Developmenthttp://

7 Framework for Protecting Human Health Assumptions: actual risk = exposure  toxicity actual risk = exposure  toxicity risk reduction = exposure reduction risk reduction = exposure reduction

8 Primary Environmental Laws 1938 Federal Food, Drug, and Cosmetic Act 1938 Federal Food, Drug, and Cosmetic Act 1948 Federal Water Pollution Control Act (also known as the Clean Water Act) 1948 Federal Water Pollution Control Act (also known as the Clean Water Act) 1955 Clean Air Act 1955 Clean Air Act 1965 Solid Waste Disposal Act 1965 Solid Waste Disposal Act 1970 National Environmental Policy Act 1970 National Environmental Policy Act

9 Primary Environmental Laws 1988 Lead Contamination Control Act 1988 Lead Contamination Control Act 1988 Medical Waste Tracking Act 1988 Medical Waste Tracking Act 1990 National Environmental Education Act 1990 National Environmental Education Act

10 Enforcement Compliance monitoring Compliance monitoring Civil Enforcement Actions Civil Enforcement Actions –Civil Administrative Actions informal -- communication about problem informal -- communication about problem formal -- notice or administrative order (may have penalties) formal -- notice or administrative order (may have penalties) Criminal Enforcement Actions Criminal Enforcement Actions Emergency Response/Emergency Orders Emergency Response/Emergency Orders

11 Enforcement Outcomes Settlements  agreement Settlements  agreement Civil Penalties  fines Civil Penalties  fines Injunctive Relief  tasks to be carried out Injunctive Relief  tasks to be carried out Supplemental Environmental Projects Supplemental Environmental Projects

12 Environmental Chemistry to move beyond simple descriptions of the environment, we need to quantify environmental quality to move beyond simple descriptions of the environment, we need to quantify environmental quality many approaches -- species, land-use, visual indicators, surveys many approaches -- species, land-use, visual indicators, surveys most common is to use a chemical concentrations and chemical change as the base most common is to use a chemical concentrations and chemical change as the base

13 Stoichiometry a balanced chemical equations describes: a balanced chemical equations describes: –qualitative information on what reacts with what and what is formed –quantitative information on how much reacts and how much is formed stoichiometry is the formation of balanced equations stoichiometry is the formation of balanced equations

14 Example CH O 2  CO H 2 O molecules

15 Molecules and Mass Atomic weight Atomic weight –mass of atom in atomic mass units (amu). –12.00 amu  weight of carbon atom with 6 protons and 6 neutrons –carbon listed in tables as having an atomic weight of small % of atoms have 7 and 8 neutrons (isotopes)

16 Molecules and Mass Atomic number Atomic number –the number of protons in the nucleus of an element –all isotopes of an element have the same atomic number Molecular weight Molecular weight –sum of the atomic weights for molecules

17 Example Calcium chloride, CaCl 2 Calcium chloride, CaCl atomic weight Ca 35.45atomic weight Cl molecular weight CaCl molecular weight CaCl 2

18 Mole (mol) A mole is a fixed number of molecules found in a mass of an element or molecule equal to its atomic or molecular weight A mole is a fixed number of molecules found in a mass of an element or molecule equal to its atomic or molecular weight g-mole = x molecules g-mole = x molecules # moles = mass/molecular weight # moles = mass/molecular weight e.g g C = 1 mole e.g g C = 1 mole

19 Example A sugar packet contains about 3 grams of sugar. How many moles is this? Sucrose = C 12 H 22 O 11 MW = 12(12) + 22(1) + 11(16) = 342 g/mol # mole = 3 g/(342 g/mol) = mol

20 Balancing Equations must have an equal number of each element on each side of the equation must have an equal number of each element on each side of the equation

21 Example: combustion of propane C 3 H 8 + O 2 = CO 2 + H 2 O C 3 H 8 + O 2 = CO 2 + H 2 O C 3 H O 2 = 3 CO H 2 O C33C33C33C33 H88H88H88H88 O1064 Each mole of propane requires 5 moles O 2

22 Example: combustion of propane How many g of O 2 are required to burn How many g of O 2 are required to burn 100 g propane? MW propane = 3(12.01)+ 8(1.008) = g/mol moles propane = 100 g/(44.09 g/mol) = 2.27 mol moles oxygen required = 2.27 x 5 = mol MW oxygen = 2(16.00) = g/mol mass oxygen = moles x MW = (11.34 mol)(32.00 g/mol) = 363 g O 2

23 Example: combustion of propane At STP, what volume of air at STP is required to burn 100 g propane? At STP, what volume of air at STP is required to burn 100 g propane? (11.34 mol)(22.4 L/mol) = 254 L O 2 since air is 21% oxygen by volume: (254 L O 2 )/(0.21 L O 2 /L air) = 1210 L air

24 Oxygen Demand theoretical oxygen demand - O 2 required to completely oxidize a chemical substance to CO 2 and H 2 O. Based on stoichiometry. theoretical oxygen demand - O 2 required to completely oxidize a chemical substance to CO 2 and H 2 O. Based on stoichiometry. biochemical oxygen demand (BOD) - O 2 consumed by a substance in a standard test using microorganisms for oxidation biochemical oxygen demand (BOD) - O 2 consumed by a substance in a standard test using microorganisms for oxidation chemical oxygen demand (COD) - …. standard test using strong chemical oxidants chemical oxygen demand (COD) - …. standard test using strong chemical oxidants

25 Example Determine the theoretical oxygen demand for a solution containing 200 mg/L acetic acid (vinegar)? Determine the theoretical oxygen demand for a solution containing 200 mg/L acetic acid (vinegar)? CH 3 COOH + 2O 2 2CO 2 + 2H 2 O CH 3 COOH + 2O 2 2CO 2 + 2H 2 O C 2 2 H4 4 O

26 Example MW acetic acid = 2(12.01) + 4(1.008) + 2(16.00) = g/mol = g/mol

27 Enthalpy for gases, the “heat content” depends not only on the internal energy (U) but on the pressure (P) and volume (V) for gases, the “heat content” depends not only on the internal energy (U) but on the pressure (P) and volume (V) define thermodynamic term enthalpy define thermodynamic term enthalpy H = U + PV H = U + PV depends on T depends on T units of kJ or BTU common units of kJ or BTU common

28 Enthalpy change in enthalpy in a reaction is termed the heat of reaction change in enthalpy in a reaction is termed the heat of reaction H products - H reactants =  H if there is no pressure change, then this is the heat absorbed if there is no pressure change, then this is the heat absorbed  H positive  heat absorbed  endothermic  H negative  heat released  exothermic

29 Chemical Kinetics Reaction Rates Homogeneous reactions – occur within a single phase (i.e. gas, liquid or solid) Homogeneous reactions – occur within a single phase (i.e. gas, liquid or solid) Heterogeneous reactions – occur at interfaces between phases Heterogeneous reactions – occur at interfaces between phases

30 Reaction Order Reaction order describes the number of concentration terms in the rate expression Reaction order describes the number of concentration terms in the rate expression

31 Homogeneous First-Order Rates

32 Half-Life t 1/2 is defined as the time required for the concentration to decay to half its original value t 1/2 is defined as the time required for the concentration to decay to half its original value

33 Example An underground storage tank has been leaking for many years. The groundwater concentration beneath the site is 30 mg/L. The contaminant moves 0.5 ft/day, but decays as it moves, having a half-life of 10 years. What concentration would you expect in a water supply well 1 mile away when the contaminant reaches it? An underground storage tank has been leaking for many years. The groundwater concentration beneath the site is 30 mg/L. The contaminant moves 0.5 ft/day, but decays as it moves, having a half-life of 10 years. What concentration would you expect in a water supply well 1 mile away when the contaminant reaches it?

34 Example

35 Linear form of first-order equation

36 Example H 2 O 2 → O 2 + H 2 H 2 O 2 → O 2 + H 2 Measure [H 2 O 2 ] over a period of time in a closed system. Measure [H 2 O 2 ] over a period of time in a closed system.

37 Example

38 First-order Mass Transfer Rates

39 Example The dissolved oxygen concentration at a location in a river is 3 mg/L, while saturation levels are 8 mg/L. The velocity is 2 mile/day. Considering only reaeration with a rate constant of 0.1 day -1, how far downstream does the DO level first reach 5 mg/L? The dissolved oxygen concentration at a location in a river is 3 mg/L, while saturation levels are 8 mg/L. The velocity is 2 mile/day. Considering only reaeration with a rate constant of 0.1 day -1, how far downstream does the DO level first reach 5 mg/L?

40 Example