A Battle to Be the Best: A Comparison of Two Powerful Sidestream Treatment Technologies: Post Aerobic Digestion and Anammox

Transcription

1 A Battle to Be the Best: A Comparison of Two Powerful Treatment Technologies: Post Aerobic Digestion and Anammox David Oerke/CH2M Tom Johnson/CH2M Bruce Johnson/CH2M Heidi Bauer/CH2M Steve Graziano/CH2M 2016 Vail Operator Training Seminar

2 What are PAD & Anammox? Treatment Technologies Reduction of nitrogen No supplemental carbon or alkalinity WEF Webcast 12/9/2009: Treatment for Nutrient Removal and Recovery

3 What is Post Aerobic Digestion? Aerobic digestion after anaerobic digestion Advantages: Reduction of N without chems. VSS reduction Odor reduction Struvite stabilization Challenges: Biological heat Foam

4 Example Full-Scale PAD Facilities Raw Chemically Enhanced Primary Treatment Spokane County Regional WRF Denver Metro WRD NTP 11/16 Boulder 75 th Street WWTP -10/16 Step Feed Bioreactor Membranes Solids Reduction & Nitrogen Removal Centrifuge Waste Solids Anaerobic Digesters Aerobic Digester Centrate

5 What is Anammox Anaerobic Ammonium Oxidation Advantages: Reduction of N without chems. Lower energy Challenges: Slow growth Competition with nitrite oxidizing bacteria

6 Example Full-Scale Anammox Facility Alexandria Renew Enterprises (AlexRenew) Water Resources Recovery Facility (WRRF) Wett, B., Murthy, S., Takacs, I., Hell, M., Bowden, G., Deur, A., Shaughnessy, M. (2007). Key Parameters for Control of DEMON Deammonification Process. Wat. Practice

7 Comparison of Technologies Post Aerobic Digestion Anammox Target Flow Stream Nitrogen Removal Method Entire anaerobic digestion effluent Nitrification/ Denitrification Dewatering liquors Partial Nitritation/ Deammonification - Carbon Input Degradable material from anaerobic digestion Not needed - Aeration Intermittent Intermittent Biomass Used Conventional Specialized

8 Methodology Pro2D 2 whole plant simulator: Baseline PAD Anammox CPES cost estimating system Assumptions: 75.7 ML/d (20 mgd) Aeration Basins: 5-stage Bardenpho 8.5 day SRT Biosolids facilities: 24/7 operation Disposal via land application mg/l Influent Effluent Limitation BOD TSS VSS 192 TKN 39 NH TN TP 6 1.0

9 Baseline PFD -No Treatment RAW INFLUENT PUMP STATION SCREENING AND GRIT REMOVAL PRIMARY CLARIFIERS Anaerobic AERATION BASINS Anoxic Aerobic Anoxic Aerobic SECONDARY CLARIFIERS FILTRATION PLANT EFFLUENT Recycle RAS Gravity Thickener Supernatant GRAVITY THICKENER GBT FILTRATE GRAVITY BELT THICKENER Thickened WAS Thickened Primary Solids ANAEROBIC DIGESTION Backwash BELT FILTER PRESS BIOSOLIDS Filtrate WAS

10 Post Aerobic Digestion PFD RAW INFLUENT PUMP STATION SCREENING AND GRIT REMOVAL PRIMARY CLARIFIERS Anaerobic AERATION BASINS Anoxic Aerobic Anoxic Aerobic SECONDARY CLARIFIERS FILTRATION PLANT EFFLUENT Recycle RAS Gravity Thickener Supernatant GRAVITY THICKENER GBT FILTRATE GRAVITY BELT THICKENER Thickened WAS Thickened Primary Solids ANAEROBIC DIGESTION Backwash BELT FILTER PRESS BIOSOLIDS Filtrate WAS POST AEROBIC DIGESTION

11 Anammox PFD RAW INFLUENT PUMP STATION SCREENING AND GRIT REMOVAL PRIMARY CLARIFIERS Anaerobic AERATION BASINS Anoxic Aerobic Anoxic Aerobic SECONDARY CLARIFIERS FILTRATION PLANT EFFLUENT Recycle RAS Gravity Thickener Supernatant GRAVITY THICKENER GBT FILTRATE GRAVITY BELT THICKENER Thickened WAS ANAEROBIC DIGESTION Backwash BELT FILTER PRESS Thickened Primary Solids BIOSOLIDS WAS Filtrate WAS Treated Filtrate ANAMMOX

12 Baseline: Design Criteria Average of 778 kg/d (1,715 lb/d) of carbon 3.66 m (12 ft) dia. tank for 30-day max month storage PAD: Aerobic digester volume of 4,656 m 3 (1.23 MG) Anammox: Based on DEMON process with an estimated total reactor volume of 1,079 m 3 (0.285 MG) Two SBR basins with an equally sized basin for Equalization

13 Cost Assumptions Life Cycle Assumptions: Life of Study 20 years Discount Rate 5.0 % Inflation Rate 3.0 % Capital Cost Assumptions: Start of Construction 2015 Construction Duration 2 years Markup Factor 2.38 Annual Cost Assumptions: Electricity Cost $0.0768/kWh Maintenance and Repair Cost 3.0%/year of equipment cost Biosolids Hauling Cost $20.58/wet metric ton ($18.67/wet U.S. ton) Biosolids Disposal Cost $33.07/wet metric ton ($30.00/wet U.S. ton) Trash Hauling and Disposal Cost $78.33/m 3 ($59.89/yd 3 ) Revenue $0/year Contingency 20% of annual costs

14 Mass Balance: Results Treatment Filtrate Quality Plant Effluent Biosolids Costs: Annual Capital Life Cycle

15 Results-Mass Balance -Mass Removed from

16 Results-Mass Balance -Filtrate Quality Baseline (No Treatment) Treatment with PAD Treatment with Anammox mg/l (kg/d) mg/l (kg/d) % Change from Baseline mg/l (kg/d) % Change from Baseline NH3 440 (390) 4.5 (4.0) 99% 43 (37) 90% TKN 490 (430) 45 (40) 91% 59 (51) 88% TIN 440 (390) 25 (23) 94% 93 (80) 79% TN 490 (430) 66 (59) 86% 110 (94) 78% Both sidestream treatment technologies remove significant amounts of nitrogen from the filtrate compared to the baseline.

17 Results-Mass Balance -Plant Effluent Baseline (No Treatment) Treatment with PAD Treatment with Anammox Flow, m 3 /d (mgd) 76,000 (20.0) 76,000 (20.0) 76,000 (20.0) BOD, mg/l (kg/d) 1.7 (130) 1.7 (130) 1.7 (130) TSS, mg/l (kg/d) 3.1 (240) 3.1 (240) 3.1 (240) VSS, mg/l (kg/d) 2.1 (160) 2.0 (150) 2.0 (160) NH3, mg-n/l (kg-n/d) 0.4 (30) 0.4 (31) 0.3 (19) TKN, mg-n/l (kg-n/d) 1.8 (140) 1.8 (140) 1.7 (130) NO3, mg-n/l (kg-n/d) 2.6 (200) 2.1 (160) 2.2 (170) TP, mg/l (kg/d) 0.4 (34) 0.5 (37) 0.5 (34) No significant differences between the two sidestream treatment technologies compared to each other or to the baseline.

18 Results-Mass Balance -Biosolids

19 Results-Annual Costs -Energy Use Baseline (No Treatment) Treatment with PAD Treatment with Anammox Treatment, kw Methanol Feed, kw Aeration Basins, kw Anaerobic Digestion, kw Anaerobic Digestion Energy Generation, kw (462) (452) (457) Net Energy, kw Annual Energy Consumption, kwh/yr 2,800,000 3,190,000 2,790,000 Annual Energy Cost, $/yr $215,000 $245,000 $214,000 Energy Cost Compared to Baseline, $/yr $30,000 -$1,000 Energy Cost Compared to Baseline, % 14.0% -0.5%

20 Results-Annual Costs -Chemical Use Baseline (No Treatment) Treatment with PAD Treatment with Anammox Methanol Consumption, kg/d (lb/d) 778 (1,715) - - Methanol Consumption, MG/yr (dry tons/yr) 284 (313) - - Annual Methanol Cost, $/yr $139,

21 Results-Annual Costs -Biosolids Production Baseline (No Treatment Treatment with Treatment) with PAD Anammox Biosolids Production, kg/d (lb/d) 7,982 (17,598) 6,965 (15,354) 7,878 (17,368) Biosolids Production, dry metric tons/day Biosolids Production, wet metric tons/day Biosolids Production, wet metric tons/yr 12,100 10,600 12,000 Annual Disposal Cost, $/yr $651,000 $568,000 $643,000 Disposal Cost Compared to Baseline, $/yr -$83,000 -$8,000 Disposal Cost Compared to Baseline, % -12.7% -1.2%

22 Results-Annual Costs -Total Energy, Chemical, & Biosolids Baseline (No Treatment Treatment with Treatment) with PAD Anammox Energy Use, $/yr $215,000 $245,000 $214,000 Chemical Use, $/yr $139, Biosolids Production, $/yr $651,000 $568,000 $643,000 Total Annual Costs for Energy, Methanol, & Biosolids Disposal, $/yr $1,005,000 $813,000 $857,000 Total Cost Compared to Baseline, $/yr -$192,000 -$148,000 Total Cost Compared to Baseline, % -19.1% -14.7%

23 Costs in Million Dollars Results-Capital Costs Baseline (No Treatment) Treatment with PAD Treatment with Anammox Aeration Basins $19.4 $19.1 $19.1 Aeration Basin Blowers $4.4 $4.2 $4.3 Carbon Feed and Storage Facility $ Anammox Facility - - $3.8 Post Aerobic Digestion - $5.3 - Other 11 Facilities $81.6 $81.6 $81.6 Additional Project Costs $15.6 $16.1 $15.9 Total Construction Cost $122.5 $126.3 $124.7 Percent Increase from Lowest Construction Cost - 3.1% 1.8%

24 Results-Total Annual Costs Costs in Million Dollars Baseline (No Treatment) Treatment with PAD Treatment w/ Anammox Aeration Basins $0.24 $0.23 $0.23 Aeration Basin Blowers $0.39 $0.35 $0.36 Carbon Feed and Storage Facility $ Anammox Facility - - $0.05 Post Aerobic Digestion - $ Biosolids Hauling and Disposal $1.40 $1.20 $1.40 Other 11 Facilities $1.96 $1.96 $1.96 Misc. Annual Costs & Contingency $0.20 $0.20 $0.20 Total Annual Cost $4.43 $4.04 $4.20 NPV of Annual Costs $55.1 $50.7 $52.2 Percent Increase from Lowest Annual Cost 9.7% - 4.0%

25 Results-Life Cycle Costs Costs in Million dollars Baseline (No Treatment) Treatment with PAD Treatment with Anammox Aeration Basins $22.3 $22.1 $22.1 Aeration Basin Blowers $9.3 $8.6 $8.7 Carbon Feed and Storage Facility $ Anammox Facility - - $4.5 Post Aerobic Digestion - $6.5 - Biosolids Hauling and Disposal $17.7 $15.4 $17.4 Other 11 Facilities $105.8 $105.8 $105.8 Standard Items $18.0 $18.6 $18.4 Total Net Present Value $177.6 $177.0 $176.9 Percent Increase from Lowest Life Cycle Cost 0.40% 0.06% -

26 Conclusions-1 Post Aerobic Digestion and Anammox Similarities: Excellent option for reduction of nitrogen recycled back to the liquid stream Supplemental chemicals not typically required Similar effluent quality achieved Significant removal of constituents in filtrate Less energy required for nutrient removal in aeration basins

27 Conclusions-2 Post Aerobic Digestion and Anammox Differences: Different sidestream flow streams targeted PAD removes more BOD, VSS, and Nitrogen Greater net annual cost savings for PAD Greater net energy savings for Anammox

28 Costs: Conclusions-3 Baseline (No Treatment) offers lowest capital cost Treatment with PAD offers the lowest annual cost Equivalent life cycle costs for Baseline, PAD, and Anammox: Consider PAD when N removal without chems. desired in addition to additional VSR. Consider Anammox when N removal without chems. desired in addition to energy minimization, or if future phosphorus recovery is desired.

29 A Battle to Be the Best: A Comparison of Two Powerful Treatment Technologies: Post Aerobic Digestion and Anammox QUESTIONS? David Oerke/CH2M (David.Oerke@ch2m.com) Tom Johnson/CH2M Bruce Johnson/CH2M Heidi Bauer/CH2M Steve Graziano/CH2M