1. CE 3231 - Introduction to Environmental Engineering and Science Readings for Next Class: Chapter 1.3 O hio N orthern U niversity Introduction Chemistry, Microbiology & Material Balance Water & Air Pollution Env Risk Management Material Balance I – Flow Developing a mathematical understanding of a system helps in predicting how a system will be have under a given circumstance. Developing a mass balance is often the first step engineering students take into mathematical modeling and a skill that is applied throughout engineering. Here we examine flow.

2. Lecture 15 Flow (Material Balance I)

3. Global Pandemic

4. Where are material and energy balances important within Environmental Engineering? Sustainability Green chemistry Alternative energy Smart Development Water Purification Water Quality Air Quality Laws & Regulations Sanitation Solid/Hazardous Waste Soil/Sediment Quality Remediation

5. Unifying Theories Conservation of Mass Conservation of Energy Conservation of Mass and Energy

6. Material Balances Accumulation = In – Out +/- reactions Control Volume (system boundaries) Examples: Flow, Mass Flow, Mass Flow with Reaction

7. Flow A hot tub with a volume of 1.0 m 3 is filled with a hose. The hose has a flowrate of 2.5 gal/minute. How long will it take the hot tub to fill?

8. Flow Because it will take a long time, you walk away. After 3 hours you return and notice the water was overflowing. How much water overflowed? And what was the rate of overflow once the water topped the hot tub walls?

9. Flow Sewer systems from 5 homes flow into a man-hole at the end of a subdivision. The flow from each of the houses is given below. Assuming the specific gravity of the wastewater from house one through four is 1.2, and the specific gravity from house 5 is 1.6, what is the outflow from the system if the specific gravity of the combined waste is 1.25? Flows 200 L/day (house 1) 100 L/day (house 2) 350 L/day (house 3) 250 L/day (house 4) 80 L/day (house 5)

10. Flow