Kristin Waller, PE and Ned Talbot, PE WaterJAM September 13, 2017

Transcription

1 OBG PRESENTS: OBG PRESENTS: DON'T SETTLE FOR CONVENTIONAL: Emerging Alternative Primary Treatment Technologies Kristin Waller, PE and Ned Talbot, PE WaterJAM September 13, 2017

2 AGENDA Intro to Alternative Primary Treatment Available / Emerging Technologies Case Study # 1 Ithaca, NY Case Study #2 West Point, NY Summaries and Conclusions 2

3 Primary Treatment Conventional: Initial Settling Circular or Rectangular Clarifiers GRAVITY and NATURAL FLOCCULATION Efficiency depends on Influent concentrations Detention time Surface loading: surface overflow rate Flow Path: avoid short circuiting 3

4 Enhanced Primary Treatment (EPT) Benefits Improved Removal Efficiencies Energy Savings TSS BOD Coagulant = < TP Reduces BOD to aeration Lower air flow Increased capacity Parameter % Removals Conventional EPT TSS 60% 75-85% BOD 5 30% 55-65% TP 30% 55-85% TKN 30% 30% Energy Production PS:WAS ratio Diverts Digestible Material Higher biogas yield 4

5 Enhanced Primary Treatment (EPT) Evaluations O&M Costs Available space Experience Chemical Costs rbcod for Biological nutrient removal Supplemental Carbon? Headloss Hydraulic Profile Footprint # of installations Operator Comfort Piloting? 5

6 Technology Description Chemically Enhanced PT (CEPT) Chemical Coagulation ENHANCED PRIMARY TREATMENT Technologies Ballasted Floc (HRFS) Bio-contact / DAF Primary / Primary Effluent Filtration Clear Cove* Rotating Belt Screens* High rate clarification, polymer flocculation Biosorption with thickening Filters as primary, or filter PC overflow Proprietary batch filtration and settling Ultrafine screening of raw influent *Discussed in Case Studies Today 6

7 CHEMICALLY ENHANCED PRIMARY TREATMENT (CEPT) Negatively charged particles repel Positive (+) coagulants attract negative (-) Neutrally charged attract (van der Waal's) Particles and coagulants join into floc and settle Allows for Higher SOR, Higher TP Removal 7

8 BALLASTED FLOCCULATION High Rate Flocculated Settling Adds Ballast with Coagulant Speeds floc generation, Improves settling COAGULANT POLYMER LAMELLA OR TUBE SETTLERS External Ballast Microsand Veolia ACTIFLO, WesTech Rapisand Magnetite, Evoqua CoMag Or Sludge Recycle Suez DensaDeg WesTech CONTRAFAST Lamella or Tube Settlers BALLAST MIXING TANKS BALLAST RECOVERY (I.E. MAGNETIC DRUM OR HYDRO-CYCLONE) RECYCLE CLARIFIER SLUDGE PROCESSING Smaller Footprint, Wet Weather Solutions 8

9 BIOCONTACT DAF HRAS Contact-Stabilization Aerate RAS/WAS to create famine Influent added in short sludge age Increases production of extracellular polymer Microorganisms adsorb BOD Optimizes Energy Requirements DAF (Dissolved Air Floatation) Influent Mixed with Air, Solids Float to Top Folded Flow Increases Efficiency Decreases Footprint Minimized or No chemical costs Evoqua Captivator Folded Flow DAF Biological uptake (adsorption) sequesters carbon Settling and Aeration efficiencies 9

10 PRIMARY OR PRIMARY EFFLUENT FILTRATION Pile Cloth Media Micro ScreenDiscs Compressible Media Filter Schreiber Fuzzy Filter WesTech / WWETCO FlexFilter Pile Cloth Media Filter AquaAerobic Systems Disc Filter Veolia Hydrotech Westech SuperDisc Cont BW Sand Filter Westech SuperSand Parkson DynaSand Blue Water Centra-flo With or Without Primary Clarifiers Proven Technologies (various types) Carbon Redirection to ADs 10

11 Case Study #1 ClearCove Enhanced Primary Treatment Pilot Ithaca Area WWTF 11

12 NYSERDA Demonstration Project Towards Zero-Net Energy in WWT Background Reduce aeration energy Enhance BOD removal Increase capacity of digester Improve biodegradability, inorganics removal Improve sludge processing Higher % solids, improve PS:WAS ratio Similar plant chemical usage / costs to current 12

13 ClearCove s EPT Harvester CONVENTIONAL PRIMARY CLARIFIER CLEARCOVE PILOT ORGANICS EFFLUENT FLOW EPT HARVESTER: FULL SCALE 13

14 EPT Harvester Pilot Details Influent Influen 300 Gallon Thickening Tank ClearCove EPT ClearCove EPT Sludge EPT Effluent IAWWTF Sludge Thickening Tank IAWWTF Primary Clarifier Mini-Digesters ClearCove SCP (Sludge Classifying Process) ClearCove EPT Sludge 20,000 GPD system compared to IAWWTF Primary % Removals Biogas Generation for Energy Production TSS, BOD 5, TP Two Test Digesters Two Control Digesters 14

15 Pilot Test: % Removals % Removals IAWWTF EPT Increase TSS 55% 85% 1.5x BOD 5 30% 67% 2.2x TP 30% 72% 2.4x Ithaca Influent Wastewater Ithaca Primary Effluent ClearCove Harvester Effluent 15

16 Pilot Results: Estimated Annual Energy Savings Annualized Estimation Units* Existing With EPT % Difference Aeration Energy Cost $/yr -$107,500 -$52,000-52% Total Energy Cost $/yr -$311,000 -$255,600-18% Total Energy Generation $/yr $206,100 $381, % Estimated Net Energy $/yr -$104,900 $125, % Quantified potential energy savings *Assuming 9.5 cents/kwh Enhanced Primary % BOD Removal 52% Aeration Energy Savings Enhanced Primary solids capture Higher %s, PS/WAS ratio and Biodegradability Increased Biogas Generation and Energy Production Potential by 85% All with plant chemical usage/cost similar to current Estimated IAWWTF could achieve Net-Zero, potentially even Net-Positive 16

17 Case Study #2 Rotating Belt Screen (RBS) Enhanced Primary Treatment USAG West Point Target Hill WWTP 17

18 Existing 2.06 MGD Secondary WWTP New State of the Art 2.8 MGD WWTP Background Net Zero Energy Goals More volatile solids to Anaerobic Digesters for CHP energy recovery Decreases carbon to BNR a balance Small Site Area 3 Primary Clarifiers = 4,200 SF 2 Rotating Belt Screens & Building = 1,760 SF 60% Reduction in Size to fit onsite 1 Traditional Clarifier for comfort PRIMARY TREATMENT AREA 18

19 RBS Technology Operation Auto Belt Speed Adjustment Level and Flow Monitoring PLC Based Operation Solids Removal Mat of solids maintained on belt Increases the efficiency of removals Sludge Conveyor with optional press Screen Belt Cleaning High Pressure Water Wash Air Knife Hot Water Wash Salsnes Trojan Technologies MicroScreen Hydro International EcoMat Blue Water Technologies 19

20 Rotating SIDE BY SIDE Belt Screens: COMPARISON Side by Side Comparison % Removal Parameter SALSNES SF6000 ECOMAT HYDRO MS80 Equipment Size Equipment Selection Experience TSS Removal 40-80% 30-90% 50-70% BOD Removal 20-35% 20-40% 20-35% Sludge % Solids 4-8% 5-10% TS 4-8% Water Use Sludge Thickness # of Installations

21 PILOT STUDY Set up and goals Unit Set Up Salsnes SF GPM Pump of Primary Influent PLC Controlled Goals for Study Confirm Removal Numbers Operator Confidence in Technology 21

22 PILOT STUDY Testing & Removal Results TSS Saw average 58% TSS removal for variable speed control Wet weather events had a slight impact on the results BOD BOD removals averaged 33% Only 2 BOD tests were able to be taken 22

23 PILOT STUDY Conclusions and Recommendations Salsnes Conclusions OBG design assumptions confirmed Can expect <50% TSS removals in dry weather conditions Recommendations 350µ screen with options to test 500µ and 250µ during start up Provisional dilution water for sludge 23

24 ADVANCED PRIMARY TREATMENT CAN PROVIDE: Increased % Removals in Smaller Footprints Overall Summary and Conclusions Increases in Digestible Sludge for Energy Production But balance needed with Secondary Treatment Wet Weather Solutions Many are proven technologies, or offer piloting 24

25 Kristin Waller, PE Ned Talbot, PE OBG PRESENTS: THERE S A WAY Questions? Thank you! 25