odor control - michigan water environment association presentation.pdf · why do you need odor...
TRANSCRIPT
MWEA
Collections Seminar
Odor Control September 17, 2013
Why do you need Odor Control?
• Be a Good Neighbor – Public Image Issue
• Asset Management
• Health and Safety
• What is your Goal
Not All Odors Are the Same
• Sulfur Compounds • Ammonia
• VOCs • Other
Health and Safety
• Priority 1
• Hydrogen Sulfide
– Exposure limits
– Desensitizer
• Heavier than Air
• Confined Space
Asset Management
• If you haven’t heard it, you will - SAW
• Financially or Functionally Significant
– Expensive Item
– Functionally Critical Item
• Criticality Analysis
– Risk of failure
– Consequence of Failure
Asset Management
Core Principle of Asset Management
Find the Solution that provides the
Lowest Long Term Cost
Pavement Example
Asset Management
• Odor is an Indicator Parameter
– Corrosion?
• Potential Significant Expense
– Manage Odor / Corrosion
– Prevent / Repair Damage
• Look at Overall Big Picture
– Overall Understanding of Interplay in Sewer System
– Lack of Odor?
Treat the Symptom or the Disease
• Big choice
• Do you / can you prevent it from ever happening?
• Potential huge cost ramifications
Prevention Options
• Standard Specifications
• IPP
• Maintain Dissolved Oxygen
• Control Drop Structures
• Vented System
• Discharge Structures
• Construction Material
• Eliminate Lift Stations
Treatment Options
• Chemicals – Caustic, Hydrogen Peroxide, Bioxide or equivalent
• Scrubbers • Masking Agents • Salts • Enzymes • Carbon • Ozone • Seal it and forget it.
Six Cases
1. GRSD Sewer Authority
2. North Kent Sewage Authority - Collection
3. Muskegon County Waste Management System
4. North Kent Sewage Authority - CWP
5. North Kent Sewage Authority - Four Mile LS
6. Owosso-Caledonia Sewer Authority
Case #1 – GRSD
Case #1 – GRSD
GRSD Collection System
LS
Case #1 – GRSD
-0.25
-0.20
-0.15
-0.10
-0.05
0.00
0.05
0.10
0.15
0.20
0.25
0.30
610
620
630
640
650
660
670
1 2 3 4 5 6 7 8 9 10 11 12
Pre
ssu
re (i
n W
C)
Inve
rt E
leva
tio
n (
ft)
Manhole Number
Pressure Profile (Baseline - No Blower)
Invert El. Low Average High
Ber
rien
St.
Stre
ed A
ve.
Vic
tor
Rd
.
Lake
sho
re R
d.
Sample
Event
Results
GRSD Collection System
Units 8/28/2010 8/29/2010 8/30/2010
Lab
BOD5 mg/l 380 89 285
Sulfate mg/l 4.21 21.7 10.6
Total Sulfide mg/l 5.4 3 3.9
TSS mg/l 568 46 307
Field
pH s.u. 7.75 7.63 7.99
Temp °C 21 22.95 25.02
D.O. mg/l 3.93 2.62 3.01
Dis Sulfide mg/l 4.55 5.35 3.25
H2S, Air ppm 37 66 27
% O2 % 20.9 20.9 20.9
LEL s.u. 0 0 0
The
Rest
Of
The Story
GRSD Collection System
Units 8/28/2010 8/29/2010 8/30/2010
Lab
BOD5 mg/l 380 89 285
Sulfate mg/l 4.21 21.7 10.6
Total Sulfide mg/l 5.4 3 3.9
TSS mg/l 568 46 307
Field
pH s.u. 7.75 7.63 7.99
Temp °C 21 22.95 25.02
D.O. mg/l 3.93 2.62 3.01
Dis Sulfide mg/l 4.55 5.35 3.25
H2S, Air ppm 37 66 27
% O2 % 20.9 20.9 20.9
LEL s.u. 0 0 0
ORP mv -68.6 -89.3 -61.4
Re-aeration
Example
ORP Conversion
-250
-200
-150
-100
-50
0
50
100
150
200
0
0.5
1
1.5
2
2.5
3
3.5
4
OR
P, m
v
DO
, m
g/l
Manhole
ORP Vs. DO from Forcemain Discharge
Is There Still More
To
The Story?
Collection System
Units 8/28/2010 8/29/2010 8/30/2010
Lab
BOD5 mg/l 380 89 285
Sulfate mg/l 4.21 21.7 10.6
Total Sulfide mg/l 5.4 3 3.9
TSS mg/l 568 46 307
Field
pH s.u. 7.75 7.63 7.99
Temp °C 21 22.95 25.02
D.O. mg/l 3.93 2.62 3.01
Dis Sulfide mg/l 4.55 5.35 3.25
H2S, Air ppm 37 66 27
% O2 % 20.9 20.9 20.9
LEL s.u. 0 0 0
ORP mv -68.6 -89.3 -61.4
Nitrates mg/l ? ? ?
Where Was I, Where Am I, Where Am I Going?
Results*
DO Positive Positive Positive Negative Negative Negative
ORP Positive Positive Negative Positive Negative Negative
Sulfides No Yes No No Yes No
Biology
Future (Static) Aerobic Aerobic Aerobic A/A A/A A/A
Present Aerobic Aerobic A/A Aerobic A/A A/A
Past Aerobic A/A ?? Aerobic A/A Aerobic
Results
Nitrates ?? ?? ??
* - The degree of each result does matter
Case #2 – NKSA Collection
• EPA recommends laminar (smooth) flow of wastewater
• Significant Odor Issue
• System Sealed to prevent odor complaints
• Collection System failure(s) from H2S Corrosion
Case #2 – NKSA Collection
Case #2 – NKSA Collection
• Proposed Alternate
– System Reconstruction Required
– Add carbon filters and open the system up
– Add re-aeration to system (turbulence)
– Use available grade
– Prevent from becoming anaerobic
Case #2 – NKSA Collection
• Results
– Eliminated odor complaints
– No active odor treatment in reconstructed lines
– Eliminated H2S generation
– Reduced overall construction cost
Case #3 - MCWMS
• Rehab of Existing Odor Stripper and Treatment – Rehab odor reduction building
– Replace control gates and mixers
– Update electrical
– Address issues with significant chamber corrosion
– Still issue with channels – long term proposed to cover
– Estimated cost ~$750,000
• Proposed alternate – eliminate both!
Case #3 - MCWMS
• Alternate - Plant Feed Rerouting
– Prevent the odor from ever getting to the air
– Simple
– No active treatment system, eliminate existing system
– Complete as part of overall system improvement
– Eliminate O&M costs
– Capital cost ~$600,000
Case #4 – NKSA CWP
• Process Control
– NKSA Biosolids Holding Tanks
– Avoid odor issues
– Minimize Energy
– Accomplish with Process Control
• SCADA with DO and ORP probes
– Cost – Minimal cost for probe and programming
– Saving – Significant reduction in operating costs
Case #4 – NKSA CWP
• Operational Control
Case #4 – NKSA CWP • Tracking -Trend Screen
The Look and What Smell
Case #5 – NKSA Four Mile LS
Case #5 – NKSA Four Mile LS
• Original Built in 1968
• Significant Odor and Corrosion Problem
• Located in Residential Neighborhood
• Previously Tried Chlorine Scrubber
• Station Sealed
Case #5 – NKSA Four Mile LS
• Biofilter – Treatment for wet well
– 150 ppm ave. Hydrogen Sulfide, Mercaptans
– Air Volume = 2,000 scfm
– Two Modules (package)
– 36 second bed time
– Negative pressure
– Redundant blowers
– Roof Discharge
Case #5 – NKSA Four Mile LS
• Constructed
Case #6 – Owosso-Caledonia
Case #6 – Owosso-Caledonia
• System Corrosion
• Minimal Odor Complaints
• Pilot Study – Chemical Feed
– Ventilation
• Results
– Not Effective
– Not Cost Effective
