Septic Systems and the Environment - PowerPoint PPT Presentation

Loading...

PPT – Septic Systems and the Environment PowerPoint presentation | free to view - id: 180bc8-ZDc1Z



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Septic Systems and the Environment

Description:

Treat the effluent to minimize health risks ... Potential for clogging. Large systems. Restaurants. Organic Materials: Reactions ... – PowerPoint PPT presentation

Number of Views:26
Avg rating:3.0/5.0
Slides: 42
Provided by: Gat106
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Septic Systems and the Environment


1
Septic Systems and the Environment
2
Goals of On-Site Wastewater Systems
  • Treat the effluent to minimize health risks
  • Treat the effluent to minimize environmental
    health risk
  • Dispose of the treated effluent

3
What is in wastewater?
  • Water - How much is used per capita per day?
  • Pathogens - How many are produced per capita?
  • Bacteria
  • Viruses

4
What is in wastewater?
  • Nutrients - How much per capita per year?
  • Nitrogen
  • Phosphorus

5
What is in wastewater?
  • Organics
  • Inorganics
  • VOC and HC

6
Is all wastewater the same?
  • Residential
  • Commercial
  • Restaurant
  • Industrial

7
Components of On-Site Systems
  • Source
  • Septic Tank
  • Drainfield
  • Soil

8
System Components
Source
Well
Tank
Drainfield
Treatment in Soil
Groundwater
9
Processes occurring at the source
  • Source
  • wastewater generation
  • initial treatment via chemical additions

10
Composition of Domestic Wastewater
11
The Septic Tank
Ground Surface
Riser
Riser
Influent
Effluent
Scum or
Grease Layer
Liquid
Effluent Filter
Solids/Sludge
12
Characteristic Wastewater from the Septic Tank
13
Processes occurring in the septic tank
  • settling of solids
  • floating of scum
  • nutrient reduction and transformation
  • pathogen reduction

14
Processes occurring in the drainfield
  • Filtering of solids
  • Additional nutrient and pathogen removal
  • Dispersal of effluent into the environment

15
Processes occurring in the soil
  • Nitrification Transformation of NH4 to NO3
  • Nutrient reduction
  • Pathogen removal
  • TSS and BOD reduction
  • Soil must be aerobic for order to have proper
    treatment

16
Solids
  • Settle in tank
  • Filtered out in drainfield
  • Filtered out in soil

17
Organic Materials
  • Biochemical Oxygen Demand
  • 200 -290 mg/l
  • Oil and Grease
  • Amounts vary
  • Source
  • Feces, food, fiber, etc.

18
Organic Materials Concerns
  • Oxygen demand
  • Potential for clogging
  • Large systems
  • Restaurants

19
Organic Materials Reactions
  • Microbial degradation
  • Oxygen transfer

20
Nitrogen
  • Source
  • Urine, undigested food, cleaning fluids
  • Occurs as organic-N and NH4
  • 10-16 lb. per capita per year

21
Nitrogen Concerns
  • Methemaglobanemia (blue baby syndrome)
  • Eutrophication

22
Nitrogen Reactions
  • Mineralization
  • Nitrification
  • Denitrification
  • Sorption
  • Immobilization

23
Denitrification
  • Lack O2
  • Presence of denitrifying bacteria
  • Presence of NO3
  • Presence of a carbon source (food)

24
Respiration
O2
25
Denitrification
NO3
N2 gas
26
Iron Reduction
Fe3
Fe2
27
Location of Denitrification
  • Under drainfield
  • In wetlands
  • In stream bottom sediments

28
N Cycle in Septic Systems
Mineralization
Immobilization
Nitrification and Sorption
Denitrification ?
29
Phosphorus
  • Source
  • detergents etc., excreta
  • Occurs as organic-P and orthophosphate
  • 3-5 lb.. per capita per year

30
Phosphorus Concerns
  • Water Quality - Eutrophication

31
Phosphorus Reactions
  • Sorption
  • Precipitation
  • Sediment erosion

32
Pathogens
  • Source
  • Feces, laundry
  • Bacteria
  • up to 1010 per 100ml
  • Viruses
  • up to 109 per gram

33
Pathogens Concerns
  • Health risk

34
Pathogens Reactions
  • Sorption
  • Filtration
  • Death
  • Must have aerobic and unsaturated soil for proper
    treatment

35
Wet Conditions
36
Moist Conditions
37
VOC and HCs
  • Source
  • cleaning fluids, solvents
  • Variable amounts

38
VOC and HCs Concerns
  • Carcinogens
  • Toxins

39
VOC and HCs Reactions
  • Sorption
  • Microbial transformation
  • Volatilization

40
Septage
  • Sludge must be removed from septic tank
  • Must be properly treated and disposed
  • Municipal treatment plant
  • Land applied

41
Conclusions
  • Many choices for wastewater treatment
  • In the On-site wastewater arena the first choice
    is the conventional system
  • Advanced treatment system are used when
    environmental conditions demand a higher degree
    of treatment
  • Combination of several technologies often results
    in the highest degree of treatment
About PowerShow.com