Wastewater - PowerPoint PPT Presentation

1 / 11
About This Presentation
Title:

Wastewater

Description:

Wastewater Its Journey to Treatment and Return to the Environment ESI BY-Sanni Kumar Sinha B.Tech(c.s.) 1st year Where does it all go! Where does the water from ... – PowerPoint PPT presentation

Number of Views:159
Avg rating:3.0/5.0
Slides: 12
Provided by: sine153
Category:

less

Transcript and Presenter's Notes

Title: Wastewater


1
Wastewater Its Journey to Treatment and Return
to the Environment
  • ESI
  • BY-Sanni Kumar Sinha
  • B.Tech(c.s.) 1st year

2
Where does it all go!
Where does the water from the washer go?
By gravity flow, the waste is on its way to your
local wastewater treatment plant!
3
Why treat wastewater?
  • Causes a demand for dissolved oxygen (lower DO
    levels of streams)
  • Adds nutrients (nitrate and phosphate) to cause
    excessive growth
  • Increases suspended solids or sediments in
    streams (turbidity increase)

4
Parkway WWTP
Sewagesheds
- an area where sewage is collected and delivered
to a WWPT
Bowie WWTP
Western Branch WWTP
Blue Plains WWTP
Marlboro Meadows WWTP
Piscataway WWTP
Mattawoman WWTP
approximate boundaries
5
Where do you locate the WWTP in the watershed?
Consider the four possible sites.
6
The volume of wastewater
PGC 1992 Comprehensive Ten Year Water and
Sewerage Plan
7
Levels of Treatment
  • Primary
  • removal by physical separation of grit and large
    objects (material to landfill for disposal)
  • Secondary
  • aerobic microbiological process (sludge)
  • organic matter O2 ? CO2 NH3 H2O
  • NH3 ? NO3-
  • lowers suspended solids content (into sludge)

Mostly dead microbes
aquatic nutrient
8
Secondary process
To tertiary process
From primary process
Settling collects sludge on bottom
Aeration and rapid mixing
air diffuser
9
Levels of Treatment continued
  • Tertiary (advanced)
  • anaerobic microbiological process with a
    different microbe where O2 is toxic (more sludge)
  • NO3- ? N2 (escapes to atmosphere)
  • PO4-3 if not removed in sludge in secondary
    process
  • PO4-3 Al3 ? AlPO4 (s) (into sludge)
  • - aeration to strip N2 and re-oxygenate (add DO)

10
Tertiary process
From secondary process
add methanol as food source
Effluent
Settling collects sludge on bottom
Slow mixing to keep suspended and O2 out
11
When the treatment is done
  • Effluent back to stream after
  • a final carbon filtration and
  • chlorination/dechlorination
  • Sludge very nutrient rich
  • applied directly to land as fertilizer
  • incinerated (good fuel after drying)
  • composted (Compro from WSSC)

Note Leafgro is composted leaves and grass
from MES
Write a Comment
User Comments (0)
About PowerShow.com