Municipal wastewater treatment

Municipal Water Treatment

1. Municipal Wastewater Treatment GF Piping Systems Steven Wells / 11/12/2016

2. Primary treatment to remove solid material Secondary treatment Digest dissolved and suspended organic material Nutrients nitrogen and phosphorus Sometimes disinfection to kill  pathenogenic bacteria Tertiary treatment as needed… Reverse osmosis Advanced disinfection Sludge Treatment   turns solids into fertilizer or fuel Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 2 Basic Processes, Typical Municipal Sewage Treatment

3. Basics of water treatment process at OCSD https ://www.youtube.com/watch?v=WvZJs69kr1c Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 3 Sewage Treatment

4. Produce effluent that will do as little or no harm to the surrounding environment when released Various demands depending on type of influent Various demands depending on where the water goes Closed cycle systems? Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 4 Goal of Treatment

5. Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 5 YT University Overview

6. Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 6 Process Flow: Typical Large-Scale Treatment Plant

7. Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 7 Process Flow: Subsurface Flow C onstructed Wetlands, requires lots of land

8. Objects commonly removed include trash, tree limbs, leaves, branches, and other large objects.   Bar Screen  to remove all large objects like cans, rags, sticks, plastic packets etc. Solids are collected and later disposed in a landfill, or incinerated. Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 8 Pretreatment (mechanical) removes all materials that can be easily collected

9. Sewage flows through large tanks aka settling basins, sedimentation tanks or primary clarifiers Grit Removal by slowing velocity to allow gravity to work FOG removal. Small tank with skimmers to collect fat on the surface Mechanical scrapers drive sludge towards hopper in the base of the tank. Sludge pumped to and treated at sludge treatment facilities Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 9 Primary Treatment: Sedimentation Phase

10. Degrade biological content using aerobic biological processes Bacteria & protozoa do the work Require oxygen (pumping air in these tanks is biggest consumer of electricity in the process) May also use anaerobic sections to May include secondary clarifier to settle out & separate biological floc Output still has high mineral content Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 10 Secondary Treatment (Biological)

11. anything more than primary and secondary treatment in order to allow injection into a highly sensitive or fragile ecosystem (estuaries, low-flow rivers, coral reefs,...). May be disinfected chemically (chlorine, ozone, etc ) Physically (by sand filters, lagoons and  microfiltration ) Reused: for the  irrigation  of a golf course, green way or park Groundwater replenishment or agricultural purposes if sufficiently clean Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 11 Tertiary Treatment (Chemical)

12. May be considered a type of secondary process or tertiary treatment process Focused on removal or nitrogen and phosphorus Note: both of these cause weeds or high algae growth which leads to low oxygen content in water and dead zones Nitrification is a 2 step aerobic process using different types of bacteria Oxidation of ammonia (NH 3 ) to nitrite, (NO 2 - ) by 1 bacteria From nitrite, (NO 2 - ) to nitrogen (N 2 ) by another Which bacteria species is controlled by oxygen content of water and starting material Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 12 Biological Nutrient Removal

13. Pharmaceuticals Ingredients of household chemicals Methods costly since small amounts Little to no on-line measurement of these parameters Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 13 Additional Areas of Concern

14. Pumps, mechanical movement of solids and liquids Aeration Flow, pH, ORP, oxygen, chlorine, phosphate, nitrate, turbidity, UV, ozone, etc Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 14 Instrumentation & Automation

15. Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 15 Groundwater Replenishment Process Steps

16. Orange County Sanitation District (OCSD.com) Orange County Water District (OCWD.com) Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 16 Further information

17. Questions? Municipal Wastewater Treatment | 11/12/2016 | Steven Wells 17