oxidation ditch upgrade engery savings while increasing peak flows
TRANSCRIPT
Oxidation Ditch UpgradeEnergy Savings While Increasing Peak
Flows
November 19, 2014Ryan Brauen, P.E.
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Agenda
• Background• Improvements• Funding• O2 Ditch Rehab• Energy Findings• Performance• Lessons Learned• Questions
WWTP
WRRFWater Resource Recovery Facility
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Location – Greentown, IN
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Project Need
• Age• Enforcement
– Sewer Ban: 1997• Early Warning: 1994• Hyd. Overloading (112%)• Bypasses (38)• TSS, NH3, P
– Agreed Order: 2006• Hyd. Overloading• SSO’s• Bypasses (25)• E. Coli, NH3
Need
Age
AgreedOrder
SewerBan
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Approach
2006: Collection System Field Investigations
2009: Collection System Rehabilitation
2009-2011: Flow Monitoring
2011-2012: WRRF Design
2013-2014: WRRF Construction
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Design Constraints
• Design Data– ADF: 0.58 MGD– PHF: 2.85 MGD– cBOD5: 180 mg/l– TSS: 220 mg/l– NH3-N: 30 mg/l– P: 7 mg/l
• NPDES Limits– cBOD5: 10 mg/l– TSS: 12 mg/l– NH3-N: 1.1 mg/l
(summer), 1.6 mg/l (winter)
– P: 1.0 mg/l– pH, D.O., E. Coli
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Existing Facility
• 1963: Original Facility
• 1990: O2 Ditch, Intra-Channel Clarifier, UV
• 2000: Screening, Raw Sewage Pumping, Surge Tank (EQ)
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Improvements
• New Influent Sewer• Screening• Raw Sewage Pumping• Plant Piping• EQ Blowers & Flow
Control• Chem P• O2 Ditch Mods• Flow Splitter
• Secondary Clarifiers• RAS/WAS Pumping• UV & Post Air• Aerobic Digesters &
Blowers• Sludge Dewatering• SCADA• Generator
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Funding
• SRF• Green Project Reserve
– Rain Gardens ($24,500)
– Riparian Buffer ($8,400)
– Plumbing ($900)
– D.I. Pipe ($325,000)
– Glass Block ($2,000)
– Lighting/Switches ($13,600)
– VFD’s ($51,200)
– O2 Ditch System ($161,000)
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Existing O2 Ditch & Clarifier
• Installed 1990• 2 – 40 Hp Rotors• Intra-Channel
“Boat” Clarifier– Regular Solids
Washout– Limited Control– Reduced Tank
Volume
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
O2 Ditch Improvement – Option 1
• Replacement Rotors– 2 – 30 Hp Rotors– Sys. Eff. = 90%– VFD’s– D.O. Control
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
O2 Ditch Improvement – Option 2
• Bio-Loop®
– 3 – 25 Hp PD Blowers– Motor Eff. = 90%– VFD Eff. = 98%– Fine Bubble
Membrane– 2 – 2.7 Hp
Submersible Mixers• 49 rpm• ~6-ft. dia. Blades
– D.O. Control
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
O2 Ditch Improvement – Selection
• Bio-Loop® Selected– Past Rotor Issues– Energy Savings– Flexibility– Cold Weather Ops– Lower Capital Cost
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
O2 Ditch Energy Evaluation - Existing
• 2 – 40 Hp Rotors• 13 Hrs/day (6.5
hrs/rotor)• Eff. = 80% (est.)• $0.08/kWh• ~$39/day• $14,235/yr.
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
O2 Ditch Energy Evaluation – Option 1 Replacement Rotors
• Aeration Control– 2 – 30 Hp Rotors– 16.2 Hp req./rotor– VFD turn down– 24 Hr./day/rotor– Sys. Eff. = 90%– $0.08/kWh– ~$52/day– $18,900/yr.
• Mixing Control– 2 – 30 Hp Rotors– 9 Hp req./rotor– VFD turn down– 24 Hr./day/rotor– Sys. Eff. = 90%– $0.08/kWh– ~$29/day– $10,585/yr.
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
O2 Ditch Energy Evaluation – Option 2Bio-Loop®
• 2 Mixers – 24/7– Eff. = 90% (est.)
• SCADA– Blower Runtime– Blower Hz– 5/2014 – 9/2014
• $0.08/kWh• Avg. $16/day• $5,840/yr.
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Oxidation Ditch – Energy Comparison
Existing Rotors(As Operated)
Replacement Rotors
(Aeration Limited)
Replacement Rotors
(Mixing Limited)
Bio-Loop(Actual)
Avg. Day $59 $52 $29 $25Avg. Month $1,770 $1,560 $870 $750Avg. Year $14,235 $18,900 $10,585 $9,12520 Years $284,700 $378,000 $211,700 $182,500
Annual Savings ($5,110) ($9,775) ($1,460) $020 Yr. Savings ($102,200) ($195,500) ($29,200) $0
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Effluent Quality – Post Construction
Design
MRO2/2014 – 9/2014 %
RemovalInfluent EffluentInfluent (MGD) 0.580 0.303 --- --cBOD5 (mg/l) 180 182 4.9 97.3%TSS (mg/l) 220 227 3.2 98.6%NH3 (mg/l) 30 22 0.36 98.4%P (mg/l) 7 4.2 0.50 88.1%
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Lessons Learned
• Existing Tankage• Baffle Walls• Air Curtain
– Scum/Foam• Blower Sizing
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Summary
• Flows – Design: 0.42 MGD 0.58 MGD– Peak: 1.5 MGD 2.85 MGD
• 14-50% Energy Savings• Lower Capital Cost• Operational Flexibility• Compatible with Bio-P• Cold Weather Ops
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Summary
Energy Savings Opportunities Existand Can Be Realized at Small Facilities
IWEA 2014 Oxidation Ditch Upgrade – Energy Savings While Increasing Peak Flows
Questions?
Thanks to:Town of Greentown
Klein Enterprises, LLC