. Crowne Plaza Hotel Springfield, IL NUTRIENT MANAGEMENT PROVEN METHODS FOR UPGRADING YOUR FACILITIES Steve Arant, Ed Kobylinski, James Barnard and Mark Steichen
Presentation Outline Where are we and where are we going? How will we get there Chemical P removal Biological nutrient removal (BNR) Case Study St. Cloud MN Summary B&V - 2
WHERE ARE WE AND WHERE ARE WE GOING? B&V - 3
EPA Criteria Recommendations for Rivers and Streams Ecoregion TP mg/l VI 0.076 VIII VII 0.033 VIII 0.010 VI VII IX 0.036 X 0.128 XI 0.010 X VI IX XI B&V - 4
Illinois Search for Numeric Criteria Illinois embarked upon a search for cause/effect based standards Light & Chlorophyll & Low Nighttime Biotic Nutrients D.O. respiration D.O. Impairment The search for a cause/effect approach for stream standards was aided by four teams of researchers: U of I Mark David IL SWS Mike Machesky ISU Bill Perry IL NHS Walter Hill Interim regulation Impose effluent standard instead of applying numeric criteria
Studies Results and Technology Based Limits Most streams in IL do not exhibit adverse impacts from algae/phosphorus P impact limited to streams that are un-shaded, have relatively low turbidity, granular stream bed and nonexcessive wet weather flows. USEPA, enforce narrative standard Effluent Standard Impose effluent standard on treatment plants which comprise a significant sources to phosphorus sensitive streams Effluent limit =? B&V - 6
Hypoxic Zone Future Total Nitrogen Standards?
Delivered Nutrients to Gulf of Mexico INCORPORATING UNCERTAINTY INTO THE RANKING OF SPARROW MODEL NUTRIENT YIELDS FROM MISSISSIPPI ATCHAFALAYA RIVER BASIN WATERSHEDS1 Dale M. Robertson, Gregory E. Schwarz, David A. Saad, and Richard B. Alexander, 2009 B&V - 8
NRDC 2007 Petition to Revised Secondary Limits Achievable through secondary treatment 1.0 mg/l total phosphorus 8 mg/l total nitrogen Achievable through current technology 0.3 mg/l total phosphorus 3 mg/l total nitrogen B&V - 9
How will we get there? CHEMICAL PHOSPHORUS REMOVAL B&V - 10
Chemical Phosphorus Removal Convert soluble P to particulate P Large chemical dose required to reach low soluble P Key is rapid mixing at chemical dosage point Remove particulate P Special emphasis on colloidal material Soluble P Particulate P Soluble P Particulate P Liquid Solid
Chemical P Removal Old chemical equilibrium models are obsolete Fe 3+ + PO 4 3- FePO 4 (s) (Strengite) Fe PO 4 1.6Fe 3+ + H 2 PO 4 - + 3.8OH - Fe 1.6 (H 2 PO 4 )(OH) 3.8 (s)
Chemical P Removal New phosphate complexation model Ferric Chloride OH - PO 4 3- Rapid Mix Ferric Hydroxide FeOH Ortho-P Slow Mix (e.g., AS Tanks, Floc Tanks)
Chemical Dosage B&V - 14
Effluent TSS and Phosphorus 10 mg/l TSS Chemical 0.2 mg/l P 10 mg/l TSS 0.4 mg/l P Chemical 10 mg/l TSS 0.2 mg/l P B&V - 15
Total Phosphorus, mg/l Multi-Point Chemical Addition Ferric Chloride Ferric Chloride Ferric Chloride Influent Primary Clarifier Aeration Tank Secondary Clarifier Tertiary Filter Effluent RAS WAS 6.0 5.0 4.0 3.0 2.0 1.0 0.0 Influent primary effluent secondary effluent Final effluent
Multi-Point Chemical Addition Remove ortho-p in primaries Reduces amount of phosphorus in secondary system Improves TSS and BOD removal in primaries More biogas Less aeration power requirements Polish in secondary/tertiary treatment at higher dosage Less overall chemical required Less sludge produced B&V - 17
Suspended Solids Removal Secondary Clarification and Tertiary Filtration Secondary Effluent Filter Removal Efficiency 10µm 10µm
Single Stage Tertiary Treatment Plant Permit Limit mg/l Monthly Avg. Effluent P mg/l Technology Sand Creek WWRP, Aurora, CO None 0.1 0-0.20 Deep bed filters Milford WWTP, Milford MA 0.20 0.04 0.16 Deep bed filters Piscataway WWTP, Accokeek MD 0.18 0.05 0.12 Deep bed filters Blue Plaines, Washington DC 0.18 0.11 0.12 Deep bed filters Back River WWTP, Baltimore MD 0.20 0.10 0.20 Deep bed filters Eastern Water, Orange County FL 0.25 0.14 1.14 Deep bed filters Sources: EPA 910-R-07-002 Advanced Wastewater Treatment to Achieve Low Concentration of Phosphorus; WERF Sustainable Technology for Achieving Very Low Nitrogen and Phosphorus Effluent Levels, 2009; WEF What is the Limit of Technology? A Rational and Quantitative Approach, J.B. Neethling, et al. 2009
Two Stage Tertiary Treatment Plant Iowa Hill WWRF Breckenridge CO Farmers Korner, Breckenridge CO Permit Limit mg/l Monthly Avg. Effluent P mg/l Technology 0.50 0.017 0.13 Tertiary Clarifier followed by deep bed filters 0.50 0.002 0.036 Tertiary Clarifier followed by deep bed filters Snake River, Summit County CO 0.50 0.01 0.04 Tertiary Clarifier followed by deep bed filters Rock Creek WWTP Rock Creek OR 0.10 0.04 0.09 Tertiary Clarifier followed by deep bed filters Pinery WWRF Parker CO 0.50 0.021 0.074 Two Stage deep bed filters Durham WWTP Durham OR 0.11 0.05 0.10 Tertiary Clarifier followed by deep bed filters Stamford WWTP Stamford NY 0.20 0.005 0.06 Two Stage deep bed filters Walton WWTP, Walton NY 0.20 0.005 0.06 Two Stage deep bed filters Alexandria WWTF, Alexandria VA 0.18 0.04 0.10 Tertiary Clarifier followed by deep bed filters Noman Cole WWTP., Fairfax VA 0.18 0.02 0.13 Tertiary Clarifier followed by deep bed filters Sources: EPA 910-R-07-002 Advanced Wastewater Treatment to Achieve Low Concentration of Phosphorus ; WERF Sustainable Technology for Achieving Very Low Nitrogen and Phosphorus Effluent Levels, 2009; WEF What is the Limit of Technology? A Rational and Quantitative Approach, J.B. Neethling, et al. 2009
Benchmarks for Phosphorus Removal Effluent Process 0.5 1 mg/l BPR/Chem+ good clarifiers 0.15 0.5 mg/l BPR/Chem + good clarifiers + tertiary treatment (clarifiers or filtration) 0.05 0.15 mg/l BPR/Chem + good clarifiers + two stage tertiary treatment (clarifiers plus filtration or two stage filtration) <0.05 mg/l BPR/Chem + good clarifiers + Membranes B&V - 21
Chemical P Removal Unintended Consequences High alkalinity requirements Can impact nitrification Production of vivianite Scaling of pipes and heat exchangers
How will we get there? BIOLOGICAL NUTRIENT REMOVAL B&V - 23
Biological Phosphorus Removal Bio-P bacteria selected by passing activated sludge through an anaerobic (no oxygen or nitrate) zone followed by an aerobic zone Bio-P bacteria uptake food in anaerobic zone Primary Effluent Anaerobic Zone (No Nitrates!) Aeration Tank To Secondary Clarifier Phosphorus Concentration BOD BOD drives the process
Under Anaerobic Conditions ATP Depletion O Poly-P O Poly-P P P O O Poly-P Phosphate Using Energy PHB PHB PHB PHB VFA Magnesium Adenosine Tri-Phosphate Bio-battery for energy storage O O P O O Volatile Fatty Acids O O P O O O O P O O N N O OH OH ATP H 2 N N N B&V - 25 November 16-18, 2010
PHB Poly-P Electron microscope Poly stains black, PHB stains white Poly-P B&V - 26 November 16-18, 2010
Phosphate Uptake/ ATP Production - Under Aerobic Conditions Poly-P Poly-P Poly-P Poly-P Phosphate O O P O O O O P O O Bio-battery is recharging O O P O O O N H 2 N N ATP N N Making Energy Magnesium OH OH PHB PHB Aeration Basin B&V - 27 November 16-18, 2010
Poly-phosphate stored in the aerobic zone. Phosphorus is removed with the WAS. Poly-P B&V - 28 May 11-14, 2010
Nitrification and Denitrification Nitrification NH 4 + + 2O 2 NO 3 - + 2H + + 2H 2 O Denitrification Carbon/BOD NO 3 - + 5/6 CH 3 OH + 1/6 H 2 CO 3 ½ N 2 + 4/3 H 2 O + HCO 3 - B&V - 29
Some Bio-P and Pre-dN Configurations (Effluent P < 1.5 mg/l, TN = 6 to 10 mg/l) A/O Influent AN OX SC Effluent RAS WAS Nitrate Recycle MLE Influent AX OX SC Effluent RAS WAS Influent Nitrate Recycle Johannesburg Pre-AX AN AX OX SC Effluent RAS WAS B&V - 30
Some Post-dN Configurations (Effluent TN < 3 mg/l) 5-stage Bardenpho Influent AN AX OX AX RAS Optional Carbon Source Nitrate Recycle OX WAS Effluent Denite Filter Influent Nitrate Recycle AX OX RAS SC WAS Carbon Source Denite Filter Effluent B&V - 31
Very Low Nitrogen Limits Region/Municipality Total Phosphorus Total Nitrogen Comments mg/l mg/l State of Virginia 0.3 4.0 If discharging to Chesapeake Watershed, TN = 3.0. Total nitrogen limits effective sometime after 2011. Arlington, VA 0.17 3.0 Total nitrogen limits effective sometime after 2011. Fairfax, VA 0.17 3.0 Total nitrogen limits effective sometime after 2011. State of Maryland 0.3 3.0 Total nitrogen limits effective sometime after 2011. Washington DC 0.17 4.2 Total nitrogen limits effective sometime after 2015. Tampa Bay, FL No P limit 3.0 Parts of Colorado 0.5 No N limit Parts of Colorado Mc Minneville, OR 0.07 No N limit Mc Minneville, OR Long Island Sound No P limit 4.0 to 8.0 Target nitrogen limits based on TMDL and costeffectiveness of effluent trading between facilities.
Operating Parameters Johannesburg Process Primary Effluent Mixed Liquor Secondary Effluent Pre- Anoxic Zone Anaerobic Zone Anoxic Zone Aeration Tank Secondary Clarifier WAS Mixed Liquor RAS B&V - 33
log (Conditional Solubility Product) Biological Phosphorus Removal - Unintended Consequences Struvite - Magnesium ammonium phosphate Produced in digesters and downstream solids handling Magnesium and phosphate from Bio-p process Ammonia production in anaerobic digesters 0-2 -4-6 -8 Struvite buildup in pipeline Conditional Solubility Product for Struvite Measured in Filtrate -10 4 5 6 7 8 9 10 11 12 13 14 ph Ionic Strength, u=0.1 (Sludge/Filtrate) Ionic Strength, u=0.0 (Clean Water) Note: Solubility products above the curves represent saturated conditions and potential struvite formation. B&V - 34
CASE STUDY ST. CLOUD MN B&V - 35
St. Cloud MN Design population 185,000 Design flow 17.9 mgd in 2030 Phosphorus and nitrogen removal requirements likely during the design period B&V - 36
Modified Johannesburg RECYCLE Process B&V - 37
system configuration B&V - 38
Performance Effluent Phosphorus B&V - 39
Performance - SVI B&V - 40
Performance Effluent TSS and CBOD B&V - 41
SUMMARY B&V - 42
Summary Phosphorus removal depends on removal of suspended solids Rapid mixing at point where chemical added Biological nutrient removal offers advantages of less chemical and lower solids production, and often associated with improved settling Effluent limits for phosphorus and nitrogen should consider the very high cost of advanced nutrient removal Avoid unintended consequences of nutrient removal B&V - 43
DISCUSSION B&V - 44
. Crowne Plaza Hotel Springfield, IL NUTRIENT MANAGEMENT PROVEN METHODS FOR UPGRADING YOUR FACILITIES Steve Arant, Ed Kobylinski, James Barnard and Mark Steichen
Phosphorus Chemistry Minimum Effluent Phosphorus with Alum Minimum Effluent Phosphorus with Iron ph ph
Low Effluent Phosphorus Low Effluent TSS Settleable > 100 μm Gravity settling Suspended > 1.5 μm Filterable 10 μm to 100μm Filtration, or Coag/floc/settle Total Solids Filterable < 1.5 μm Non-filterable 1.5 μm to 10μm Colloidal.08 μm to 1.5 μm Dissolved <0.08 μm Coag/floc/filter