Environmental Engineering Linking Mathematics and Chemistry to Engineering

1. Environmental EngineeringLinking Mathematics and Chemistry to Engineering Dr. Abbazadegan Graduate Students: Lauren McBurnett and Otto Schwake

2. Engineering Grand Challenges

3. Saguaro Lake Salt River Drinking Water Sources for Phoenix: The Salt River Salt River Project (SRP) Canal

4. Drinking Water Sources for Phoenix:Colorado River Agua Fria River Central AZ Project (CAP) Canals Lake Pleasant

5. Coagulation/Flocculation/ Sedimentation • Formation of floc (precipitate) which attaches to pollutants and removes them as they settle

6. Disinfection • Chemical reaction used to destroy harmful microorganisms Ozonation Ultraviolet Lamps (UV)

7. Calculating Chlorine Demand • Bleach (NaClO) • Na=23.0 g/mol • Cl=35.5 g/mol • O=16.0 g/mol • Density of bleach = 1.11 g/ml • Need 2 mg/L Cl

8. Calculating Chlorine Demand • Total molecular weight of NaClO (bleach) • 23.0 g/mol + 35.5 g/mol +16.0 g/mol = 75.5 g/mol • bleach needed • Density of bleach = 1.11 g/ml • bleach needed • Commercial Bleach is 5% NaClO • You are given a concentration of 0.5% • What volume of 0.5% NaClO solution do you need to treat 1L of water?

9. Advanced Treatment Additional treatment for removal of specific chemicals (pharmaceuticals), pH adjustment, softening, and/or removal of odor or color causing compounds Pipe Scale Algae

10. What is turbidity?

11. What is turbidity? • Measure of cloudiness caused by suspended particles • Turbidity is the measurement of how much light can travel through water with scattered living or nonliving particles in the water • Usually measured in Nephelometric Turbidity Units (NTU) • Water with high turbidity is murky and dark, and is unhealthy to aquatic life • Low turbid water is more transparent and is healthier for aquatic life

12. Why is turbid water a problem? • Excessive turbidity in drinking water is aesthetically unappealing, and may also represent a health concern • Turbidity can provide food and shelter for microbes • By reducing their exposure to attack by disinfectants • If not removed, turbidity can promote growth of microbes in the distribution system • Leads to waterborne disease outbreaks which have caused significant cases of gastroenteritis throughout the United States and the world • Although turbidity is not a direct indicator of health risk, numerous studies show a strong relationship between removal of turbidity and removal of protozoa

13. What is pH • The pH of a liquid is a measure of its acidity or basicity • Mathematically, pH = - log[H+], where [H+] = concentration of hydrogen ions in moles/liter • A pH of 7 is considered neutral • Liquids with pH less than 7 are acidic and greater than 7 are neutral • A scale of pH values and common liquids is provided

14. pH Scale

15. Alkalinity • A measure of a liquid’s capacity to neutralize acids • Buffer against changes in pH when an acid is added • Important in determining a stream's ability to neutralize acidic pollution from rainfall, industry, or wastewater • Influenced by rocks and soils, salts, certain plant activities, and certain industrial wastewater discharges

16. Hardness • Sum of the multivalent cationsin a water • Positively charged ions • The majority water hardness is due to calcium and magnesium ions • Cause scaling in water pipes

17. Hardness • Harder waters make it is more difficult to form suds with soap • Soft waters tend to feel “slimy”

18. Dissolved Oxygen • Dissolved oxygen (DO) • The amount of oxygen dissolved in a liquid • Oxygen concentration in water is important to fish and other aquatic life

19. Dissolved Oxygen • Insufficiently treated wastewater released into a body of water can decrease DO concentration • Nitrogen and phosphorous runoff from fertilizers or from wastewater can cause eutrophication in bodies of water • Leads to decreased DO as plants decompose

20. Eutrophication • Hypertrophicationis the ecosystem response to the addition of artificial or natural substances through fertilizers or sewage, to an aquatic system. • Such as nitrates and phosphates • “Bloom" of phytoplankton in a water body as a response to increased levels of nutrients • Negative environmental effects include hypoxia • Depletion of oxygen in the water which causes a reductions in specific fish and other animals

21. Conductivity • Used to measure the ionic content in a solution • In many cases, conductivity is linked directly to the total dissolved solids (TDS)

22. Total Solids Total Solids (TS) = Total Dissolved Solids (TDS) + Total Suspended Solids (TSS) Total Solids Dissolved particles (TDS) Suspended particles (TSS)

23. Salinity Classifications • United States Environmental Protection Agency (EPA) • TDS is a secondary standard • < 500 mg/L • Excessive TDS can be harmful to plant life

24. Nitrogen Cycle • The process by which nitrogen is converted between its various chemical forms • This transformation can be carried out through • Biological processes • Physical processes • Fixation • Ammonification • Nitrification • Denitrification

26. Carbon Cycle

27. Review Lesson with Lauren and Otto at the school visit Day 2

28. Have fun at ASU Day 3

29. At ASU • The students will be provided with several unknown water sources • The students will then design an experiment using water quality parameters to identify and distinguish between the “unknown” water sources

30. At ASU • Water Quality Parameters which the students will have at their disposal are: • Nitrate • Nitrite • Bromide • Chlorine • Iron • Copper • pH • Conductivity • Turbidity • Ammonium • Ammonia