Introduction to Wastewater
Treatment
Mark O. Liner, P.E.
Naturally Wallace Consulting
Wastewater Engineering
How to go from A to B to C?
Treatment of Natural Gas Condensate
Reverse Engineering
• Glass of water and add:
– Sand
– Sugar
– Salt
– Oil
• How do you make this water
clean?
Design Steps
Decision: Wastewater Treatment is Needed
Basis of Design
Process Selection
Preliminary Design
Final Design
First Step: Basis of Design
• Most important step of the project
!!!
– Foundation for all decisions
– Dictates project $$$s
• Changing the Basis of Design
halfway thru the project is like
changing ….
Basis of Design Data
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Flow
Influent Characterization
Effluent Requirements
Miscellaneous Considerations
Flow – Measurement
• Weirs
• Flumes
• Meters
Flow - Domestic
Flow - Industrial
50000
45000
40000
Concentration (mg-BOD/l)
35000
30000
Typical Basis of Design “Box”
25000
20000
15000
10000
5000
0
0
50000
100000
150000
200000
250000
Flow (gpd)
300000
350000
400000
450000
500000
Flow - Equalization
• Hold and discharge
Equalization
Treatment
 Treat as it comes
Equalization
Treatment
Flow – Design Numbers
• Minimum and maximum hourly
flow
– For pipe/channel sizing
• Average daily flow
– For mass balance, chemical usage,
and sludge production
Characterization - Analytes
• Solids
– Total (TS)
– Dissolved (TDS)
– Suspended (TSS)
• Organics
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Biodegradable (BOD)
Chemically Oxidized (COD)
Volatile (VOC)
Oils (O&G, TPH)
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Nitrogen
Phosphorus
pH
Alkalinity
Metals
Bacteria/Algae
Characterization - Table
Effluent Requirements
• Typically set by government
• Depends on disposal method
– River
– Groundwater
– Land
• Moving target ???
Miscellaneous
• Site Constraints
– Land Availability
• Climate
• Money
– Capital Costs
– Operating Costs
• Time
– Start date
– Project Life
Design Steps
Decision: Wastewater Treatment is Needed
Basis of Design
Process Selection
Preliminary Design
Final Design
Second Step:
Process Selection
• Given a Basis of Design, what is
the best way to go from A to B to
C???
• Experience is crucial in this step
• Engineer/Vendor dance
Process Selection
Process
Coffin
Butte Selection
Landfill, Oregon
Proof of Concept
Pumped flow from leachate
barrel, Masterflex peristaltic
Standpipe, unglued grease slip fit to elbow
Distribution header same as underdrain
Collection header same as underdrain
Inexpensive poly tank
44-gal, AES BT44
Recirc
Inexpensive poly tank
44-gal, AES BT44
Masterflex peristaltic
bh
bh
Tank 1
tu
Tank 2
tu
tu
bh
bh
tu
tu
tu
tu
To
drain
Tank 3
tu
tu
Tank 4
bh tu
bh
bh
tu
Blocks
tu
tu
BOD Removal - passive
Nitrification /
Anammox – FBA
(aerated)
Nitrification /
Anammox - FBA
(aerated)
tu
Denitrification /
metals removal
Graduated poly tank
55-gal with lid, AES T55
Process Selection –
Pilot Plant
Process Selection –
Primary Treatment
• The lowly septic tank – the “greenest”
wastewater treatment technology
System Selection –
Primary Treatment
• Solids removal
– Screening
– Grit Removal
– Sedimentation
• Floatation
– Dissolved Air
Floatation
– Oil/Water Separator
System Selection –
Biological Treatment
• Soluble wastewater
can not be removed
as a solid
• So, we have bacteria
eat it and remove
them
• The trick is to create
an environment for
them to live and
STAY
System Selection –
Secondary Treatment
System Selection – Biological
Treatment
• Design Considerations
– Aerobic and anaerobic bacteria
– Periodic sludge removal
– Solids separation to keep bacteria
from flowing downstream
– Nutrient requirements (industrial
• Limits
– 30 mg/L Biochemical Oxygen
Demand
– 30 mg/L Total Suspended Solids
System Selection –
Tertiary Treatment
• Filtration
– Membrane
– Sand
– Carbon
• Chemical Addition
– pH Adjustment
• Disinfection
– Ultraviolet
– Chemical
Design Steps
Decision: Wastewater Treatment is Needed
Basis of Design
Process Selection
Preliminary Design
Final Design
Preliminary Design
• Drawing set to build consensus
– Process Schematic
– Site Plan
– Hydraulics
Process Schematic
Site Plan
Hydraulic Profile
Design Steps
Decision: Wastewater Treatment is Needed
Basis of Design
Process Selection
Preliminary Design
Final Design
Final Design
• Selection and sizing of minor
equipment
– Pumps and piping
– Tanks
– Instrumentation
– Aeration Equipment
– Concrete
– Electrical
Coordination of All Disciplines
Final Design
• Communicate what is to be built to
contractor
• Basis of cost estimate for Owner
and cost quote from contractor
• Represents details from all
disciplines
Thank You
Lagoon Technology
Mark O. Liner, P.E.
Naturally Wallace Consulting
Lagoon ???
• More lagoon systems in the USA
than any other system
• Easy to build and maintain
• Very little is written about them
– Not much to say!!!
Types of Lagoons
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Anaerobic
Facultative
Polishing
Partial Mix
Complete Mix
High Performance
Batch Reactor
Equalization/Storage
Evaporation/Cooling
Lagoon Applications
Covered Agricultural
Mine Water Treatment
Contaminated Stormwater
Advanced Domestic Wastewater
What is it???
• Constructed basin
• Lined
• Water level control
Sludge Lagoon in Slovenia
What are they good for?
• What are lagoons good for?
– Solids Management
• Removal and Storage
– Oxidation of Organics (BOD)
• Naturally
• Mechanically
– Hydraulic Equalization
• Smooth out the peaks
How do you design???
• Function related to design
– Water depth
– Surface area
– Detention time
Anaerobic Lagoon (6.0 meter deep)
Facultative Lagoon (1.5 meter deep)
Solids Removal
• What are solids?
– Organics (bacteria)
– Inorganics (silt and sand)
– Algae
• Sedimentation rate
– Wind/Turbulence
– Type of solids
– Concentration of solids
Settling Time
Sludge Accumulation
• Settled solids undergo digestion and
compaction over time
• Rule of Thumb: 0.5 m3/m3/d sludge
accumulation for domestic wastewater
Sludge Accumulation Plot
Algae
• Employed in facultative lagoons
• Diurnal cycle cause fluctuations in
– Dissolved oxygen
– pH
– Solids
• Measured by Chlorophyll Alpha
test
Organics Removal
• Simplified model assumes steady
state complete-mix reactor
• Equation:
Government Design
Advanced Design
• Current Advanced Design Methods
– L. Rich
– Grady and Daigger
– Metcalf & Eddy
• Performance Modeling by Biomass
Growth
– not BOD removal
• Same Modeling Techniques That Are
Used For Designing Conventional
Sewage Plants
Linvil Rich
Theoretical Relationship
Anaerobic Lagoons
• Deep > 3 meter
deep
• Covered
– Grease cap
– Floating cover
• Loading
– 0.04 – 0.30 kgBOD/m3/d
• Detention Time
Aerobic Lagoons
• Taking oxygen in gas phase to
water in liquid phase
• Passive = ambient transfer
• Active = mechanical
– Floating Aerators
– Blower and Diffusers
Aeration by Diffusers
How much oxygen?
• Calculate mass of oxygen required
for bacterial degradation AND
digestion
• Correct for field conditions
Mixing
• Lagoons have low
solids
• Low energy/volume
• Large volumes!!!
• 1-2 W/m3 = rule of
thumb
Short Circuiting
Short Circuiting
Civil Design
• Site Soils and Water
• Seal
Soils Testing for Lagoons
• Minimum
Requirements
– Four borings per 0.5
acres
– Depth to 10’ below
design floor
– One boring to 25’
– Borings located at
deepest excavation
• Vertical Separation
– Borings at borrow pits
– 4’ between pond seal and
for nature and
maximum groundwater level
consistency
– 2’ separation permitted for
synthetic liners
Lagoon Seals
– Percolation less than 1/16” per day at
6’ water depth
– Soil seals shall be clay or include
bentonite
• Minimum thickness of 4”
– Synthetic Seals
• Greater than 30 mil thickness
• Anchored at berm and vented
– Empirical testing required to
document compliance
Liner Systems
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Clay and Bentonite Soil
Synthetic
Clay Geomembrane
Asphalt/Concrete
Installation of Synthetic Liner
Boot Installation
Seam Testing
Water Balance Testing
• Seepage rate must be less than 500
gallons per acre per day
Lagoon Equipment
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Aeration
Covers
Baffles
Proprietary
Aeration Equipment
• Floating
Mechanical
• Submerged
Diffusers
Covers
• Covers
– Conserve heat
– Control odors
– Prevent algae
Baffles
Proprietary Systems
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Parkson – BioLac
EDI – ATLAS
Lemna – BTP
Nelson Environmental
EDI’s ATLAS
Internal Clarifier
Berm Failure
Berm Failure
Berm Inspection
Floating Liner
Liner vent
Whale of a Liner
Thank You