Pavel Hajda, Ph.D., P.E., Symbiont

Transcription

1 Pavel Hajda, Ph.D., P.E., Symbiont

2 IAWA Nutrient Study 2. Supplemental analysis 3. Other efforts 4. Conclusions

3 1. Identify technologies widely applicable to P and/or N removal upgrades 2. Assess the expected performance of those technologies 3. Express the above as effluent standard concepts 4. Support reasonable technology requirements in Springfield

4 Literature review focusing on established technologies Critical assessment of the statistical basis of performance Qualitative identification of sustainability issues (chemicals, sludge, and energy) Only incidental coverage of costs

5 Biases: where, when, for how long, in what plant context potential gain or loss (information source/user) Approach in this study: reasonable target plant (not best in class) central tendency of sustained operation

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7 Configure activated sludge for biological phosphorus removal Add metal salt to precipitate/adsorb dissolved phosphorus Enhance solids removal beyond conventional secondary clarification

8 Tertiary chemical not required Tertiary solids removal not required BPR (mostly) w/o chemical Nutrient Total Phosphorus (TP), mg/l* Relative Removal* Typical Raw Municipal Wastewater Level 0: Secondary Treatment Level 1P: Basic Municipal Phosphorus Removal Retrofit New Construction Level 2P: Enhanced Phosphorus Removal Level 3P: Limit of Technology Phosphorus Removal 4 to 8 4 to % 20% 70% 80% 90% 98% *Annual average/median.

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10 How implemented: combine biological nitrification with pre-anoxic zones (MLE), post-anoxic zones (Wuhrmann), simultaneous denitrification (macro or micro); and/or separate-stage (tertiary) denitrification activated sludge or attached-growth system

11 Tertiary treatment not required Supplemental carbon not required Pre-anoxic zones sufficient Nutrient Typical Raw Municipal Wastewater Level 0: Secondary Treatment Level 1N: Basic Municipal Nitrogen Removal Retrofit New Construction Level 2N: Enhanced Nitrogen Removal Level 3N: Limit of Technology Nitrogen Removal Total Nitrogen (TN), mg/l* Total Inorg. N (TIN), mg/l* Relative Removal (TN)* 25 to to % 20% 50% 70% 80% 90% *Annual average/median.

12 Existing configuration imposes constraints: plant type tank size/configuration footprint hydraulics solids processing and return streams

13 Upgrade choices have impacts: reliability/controllability costs, footprint hydraulics/pumping, electricity use chemical use/solids processing staff needs (complexity) sustainability

14 For phosphorus removal: reduce chemical/solids impacts: BPR avoid pumping: do without adding tertiary treatment

15 For nitrogen removal: reduce chemical/solids impacts: rely on wastewater carbon (pre-anoxic zones) avoid pumping: do without adding tertiary treatment

16 Very site-specific, but tend to increase with number of nutrients to be removed stringency of nutrient limits existing plant/process constraints for unit costs ($/gal): decreasing plant capacity

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18 Making the same limit harder to meet: shorter averaging periods (small sample n) mean harder than median absolute compliance harder than probabilistic local conditions (influent, temperature ) full inclusion of unknown refractory fractions the rest of the permit (N/P, NH 3, Al, Fe, Cl -, SO 2-4 )

19 No standards for small plants Annual medians for the rest: TP at Level 1P if nitrogen: TIN at Level 1N, with relative removal as an optional compliance pathway

20 Report not strong enough to justify [Level 1P] standards

21 Nutrient workgroup discussions on 11/28/ mg/l monthly average TP widely met in IL Follow-up call w/ IAWA on 12/8/11 Region 5 expected to insist on 0.5 mg/l TP more detailed analysis of IL plants needed size, age, current technologies, upgrade needs expected to meet 1.0 and 0.5 mg/l cost information would be useful

22 IAWA s objective: support Level 1P standard Analysis of existing IL plant data to project the impact of 0.5 mg/l vs. 1.0 mg/l standard capacity, plant type, TSS/TP limits and 12 months of performance (calendar 2011) age data lacking, technology data limited initial data sorts available for this presentation

23 Category Description Notes 1 activated sludge includes SBRs but not ditches and fixed-film hybrids 2 fixed film trickling filters, RBCs, and their combinations 3 fixed film hybrids TF/RBC combined w/ activated sludge or ditch 4 aerated lagoons rare above 1 MGD 5 oxidation ditches includes combinations with activated sludge Other Descriptors nitrification (Y/N) tertiary filtration (Y/N) Notes determined from the presence of ammonia limits several types included in the database

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35 IWEA Nutrients Committee: Nutrient Survey results in late spring or early summer 2012 focused on available and planned nutrient removal technologies and costs Technology Standards Stakeholder Subgroup 18 volunteers venue likely to bring other efforts together

36 The rulemaking outcome likely to reflect technology performance expectations conclusions from statewide and plant-specific data upgrade cost expectations All of the above likely to be subjective promote sensible outcomes by committed participation in the rulemaking process

37 Pavel Hajda Symbiont (414)