April 29, 2012 Should We Do More with Less or Less with More? The Next Frontier of Wastewater Treatment

Transcription

1 April 29, 2012 Should We Do More with Less or Less with More? The Next Frontier of Wastewater Treatment Chamindra Dassanayake, PhD, PE National Wastewater Service Leader

2 Agenda Drivers for More with Less or Less with More Process Target Based SOPs Organism Physiology Oxygen Uptake Rate (OUR) How OUR can be used for Target Based SOPs Conclusions Q&A

3 Doing More with Less A Culture Change?

4 The Drivers for Doing More with Less Budget constrains deferring capital improvements Tight sites Reducing O&M

5 The Drivers for Doing Less with More Conservative design safety factors impacting process reliability Impacts to downstream WWTP from upstream satellite water mining

6 Operational Optimization vs. Design Design Use best available rules of thumb Based on global performance parameters (F/M, influent/ effluent parameters) Organism physiology impacts not accounted for Operational Optimization Organism physiology is used to find optimal operating points

7 Data Collection Process Target Based SOPs Process Targets Transition from How Black to Do Box More to Physiology with Less? Based Approach

8 Agenda Drivers for More with Less Process Target Based SOPs Organism Physiology Oxygen Uptake Rate (OUR) How OUR can be used for Target Based SOPs Conclusions Q&A

9 Process Target Based SOPs - The Etched Fly Effect Reduced 80% spillage Why? Schiphol Airport - Amsterdam When people see a target they hit it!!

10 Agenda Drivers for More with Less Process Target Based SOPs Organism Physiology Oxygen Uptake Rate (OUR) How OUR can be used for Target Based SOPs Conclusions Q&A

11 Organism Physiology 101 Humans Bugs Cardio Resting Heart Rate Stress Heart Rate Cardio Resting respiration rate Peak respiration rate Blood Quality Cholesterol Sugar/Glucose Blood Quality rrna/atp content Mitochondria Body Fat Content BMI Body Fat Content Packed lunch

12 Cutting Edge Organism Physiology Tools Fluorescent In Situ Hybridization (FISH) FISH Fluorescent In Situ Hybridization ATP Analysis rrna Time consuming High skill required Invasive No real time pulse Expensive $$$ Micro Electrodes

13 Agenda Drivers for More with Less Process Target Based SOPs Organism Physiology Oxygen Uptake Rate (OUR) How OUR can be used for Target Based SOPs Conclusions Q&A

14 Physiology Insight Made Simpler - Oxygen Uptake Rate (OUR) Simple Cheap Rapid Low skill level needed Immediate Wow!!!! Much More with Less? Non-Invasive - near real time response Or Snake Oil?

15 OUR tracks the Main Oxygen Consumption Reactions(/Bugs) in Activated Sludge Oxygen RAS Heterotrophs (Carbon) C + O 2 = CO 2 + WAS Nitrifiers (Ammonia) NH 3 + O 2 = NO O 2 Starvation/death (Endogenous)

16 OUR What is the basis for OUR? Peak or R max Nitrifiers or Heterotrophs OUR = R = YK C b *C s Endogenous NH4 or Carbon Ks Substrate Concentration (Cs) Peak OUR = R max = (YK *K s )*C b constant

17 How is it measured? Readily available equipment at WWTPs DO Probe BOD Bottle Mixer/ Stirrer Strip Chart Recorder

18 OUR Determination 9 Endogenous O 2 Uptake Peak Nitrification + Endogenous O 2 Uptake Peak Carbonaceous + Peak Nitrification + Endogenous O 2 Uptake O (mg/ L) 5 Add NH 4 Cl Add organic substrate Δy OUR= Δy Δx 1 Δx SOUR= OUR g MLVSS in Sample Time (mins)

19 Agenda Drivers for More with Less Process Target Based SOPs Organism Physiology Oxygen Uptake Rate (OUR) How OUR can be used for Target Based SOPs Conclusions Q&A

20 OUR Can Measure Organism Robustness t=0 Feast/ Famine (A/O) sludge is more robust Stronger Weaker

21 % rrna SOUR Estimates Bug Performance Differences due to Physiology rrna Content Physiological difference Strategy A Strategy F

22 OUR can be Used to Correlate Bug Viability and Bulking Bulking No Bulking

23 Endogenous SOUR Predicts Instability Case Study Q/2 MLVSS=2000 Train A SRT= 12 days DO=2 Q/2 BOD=5 mg/l Q RAS NH4-N=<0.5 mg/l WAS Q/2 MLVSS=2000 Train B SRT= 12 days DO=2 Q/2 BOD=5 mg/l RAS NH4-N=<0.5 mg/l WAS

24 Endogenous SOUR Predicts Instability Case Study

25 SVI OUR allows Early Detection and Prevention of Sludge Instability (Bulking) Poor Settling Stable Unstable Good Settling SOUR (mg O2/g-MLVSS-h) 2 minute test predicts instability days earlier Usually takes > 60 days to recover if detected late

26 OUR allows monitoring of nitrifier health & populations Q/2 SRT= 12 days Q/2 NH4-N <0.5 Q RAS WAS Q/2 SRT= 8 days RAS Q/2 NH4-N <0.5 WAS

27 OUR allows monitoring of nitrifier health & populations R= K C b *C s R max = (K *K s )*C b Constant (physiology)

28 Peak Nitrification SOUR (mg O2/ 2500 mg/ L MLVSS OUR allows monitoring of nitrifier health & populations R 12d Cb 12d = = R 8d Cb 8d % = More Nitrifiers SRT= 8 days SRT=12 days R = Peak nitrification rate Cb = Nitrifier concentration Days of Operation

29 Peak Nitrification SOUR (mg O2/ g-mlss-h) OUR can be used to optimize SRT for nitrification Train 1 Train 3 Train Basin 5 SRT increased from 6 to 8 days Days of Operation

30 SOUR (mg O2/ g-mlvss-h) OUR allows early toxicity detection and management Toxic Episode Detection Basin Taken Offline, Aerated If BOD used, 5d needed too late to recover basin!! 50 5d Toxic Episode Recovery 20 Spiked SOUR 10 Unspiked SOUR Time (days)

31 Agenda Drivers for More with Less Process Target Based SOPs Organism Physiology Oxygen Uptake Rate (OUR) How OUR can be used for Target Based SOPs Conclusions Q&A

32 Final Thoughts Process target based SOPs is essential to do more with less or less with more The culture change, physiology not black box Understanding Physiology can be expensive But It does not have to be. OUR is a cheap and easy tool to ride the wave

33 Questions?

34 T H A N K Y O U Chamindra Dassanayake, PhD, PE Malcolm Pirnie The Water Division of ARCADIS (972)