Treatment Optimization: What s

Transcription

1 Treatment Optimization: What s Possible Glen T. Daigger, Ph.D., P.E., BCEE, NAE Professor of Engineering Practice President and Founder, One Water Solutions Presented at Michigan Water Environment Association Annual Process Seminar: Using Technology to Get More Out of Your Facility Eagle Eye Banquet Facility Chandler Rd. East Lansing, MI November,

2 The Water Profession Must Address Three Principal Priorities

3 1. We Must Fundamentally Change Our Approach to Water Management to Avoid Stress Population Growth Increased Living Standard Climate Change Urbanization Linear System Nearly Half of Human Population Will Experience Water Stress by 2025

4 Portfolio Approach to To Much/To Little Water Proven Successful Water Supplies Provided by Portfolio of: Efficiency Storage: Surface Aquifer Storage and Recovery Local Water Capture: Rainwater Harvesting Restoring Local Ecosystems Reclamation and Reuse Desalination Flooding Addressed Successively by: Conventional Measures: Drainage Dikes and Levees Rainwater Capture Green Infrastructure Spatial Planning and Implementation (Room for the River)

5 Eliminating Biases May Lead to Different Solutions Water Supply Wastewater Management Traditional Approach What are the Available Surface and Ground Water Sources? What are the Applicable Discharge Requirements? Revised Approach What are the Available Sources of Reuse Water? How Can the Effluent be Best Reuse?

6 Built and Natural Infrastructure Increasingly Being Integrated to Create Multiple Benefits

7 2. Water Management Must Become Much More Resource Efficient to Sustain Into the Future Biodiversity Loss Nutrients Nitrogen Phosphorus Climate Change Chemical Pollution (Not Yet Quantified) * Rockström, et al., Nature, , September, 2009,

8 Relative Price Commodity Price Volatility is Consequence of Resource Constraints 10 Phosphorus Copper Energy Commodities Natural Gas Ag Raw Materials 0 Jun-83 Dec-88 Jun-94 Nov-99 May-05 Nov-10

9 3. The Human Right to Water and Sanitation Must be Extended to All On 28 July 2010, through Resolution 64/292, the United Nations General Assembly explicitly recognized the human right to water and sanitation and acknowledged that clean drinking water and sanitation are essential to the realisation of all human rights. The Resolution calls upon States and international organisations to provide financial resources, help capacity-building and technology transfer to help countries, in particular developing countries, to provide safe, clean, accessible and affordable drinking water and sanitation for all. Resolution A/RES/64/292. United Nations General Assembly, July 2010

10 Approximately Half of the Human Population Lacks Safe Water, and Less Than 20 % of Wastewater is Treated ~3 Billion Without Water at Home or in the Vicinity (45 %) ~ 4 Billion Without continuous Access to Water (60%) ~4.5 Billion With No Sewerage (70 %) ~ 5.5 Billion With No Treatment (80%)

11 Compliance with Human Right Evaluated Using Six Criteria Evaluated on Relevant Scales Sufficient Quantity 5 4 Accessability Safety Availability Affordabilty Equity, Non-Discrimination IWA, Manual of the Human Rights to Safe Drinking Water and Sanitation for Practitioners, 2016

12 The Water Profession Must Address Three Principal Priorities 1. Change Water Management to Avoid Water Stress 2. Become More Resource Efficient 3. Extend Human Right to Water and Sanitation to All

13 Water and Resource Recovery Facility (WRRF) of the Future Must: Produce Product Water Which: Matches Water Quality Standards of Receiving Water Bodies Meets Fit for Purpose Water Reuse Standards Process Increased Peak Wet Weather Flows Recover a Wide Varity of Products: Energy Nutrients Organics Other Materials Adapt to Evolving Roles in the Overall System: Water and Resource Recovery Resource Recovery with Upstream Water Recovery

14 Michigan, Through MDEQ and MWEA, Leading Transition to Utility of the Future (UOTF) Chapter One Introduction Chapter Two The N-E-W Paradigm Chapter Three Education and Training Chapter Four Alignment with State of Michigan Programs Chapter Five Today s Challenges & Opportunities Chapter Six Regulatory Policy and Support Chapter Seven Call to Action Chapter Eight Case Histories

15 Secondary Clarifier Capacity Determined by Sludge Loading and Characteristics

16 80 mgd Akron, OH Water Reclamation Facility to be Upgraded to 280 mgd Peak Wet Weather Capacity 2014 Averages: 74 mgd Annual Average 266 mgd Peak Firm Capacity 210 mgd Preliminary 150 mgd Primary 110 mgd Secondary

17 Conversion of Bioreactors to Step Feed Provided Secondary Clarifier Solids Loading Rate (SLR) Control Four-Pass Basins with Feed Channels Make Conversion to Step Feed Straightforward More than 40:1 Length:Width Ratio Results in Sludge with Excellent Setting Characteristics Unit 6 (of 6), with former Step Feed Capabilities, Used for Testing: Unit 5 and 6 Secondary clarifiers (final settling tanks [FSTs]) Density current baffles Larger and deeper center wells Energy dissipation inlets (EDI) Unit 5 FSTs same side depth, weir elevations as Units 1-4

18 FST Unit 5 and Foot-Diameter (FST s) Modified for Testing, as Follows: Peripheral Baffle EDI 5A X B X X C X 12 6A X X 12 6B X X 12 6C X X 12 Sidewater Depth (ft)

19 Clarifier Stress and Flow Pattern Tests Quantified Actual Capacity and Characteristics

20 Sludge Settling and Flocculation Characteristics Quantified

21 Extended High-Flow Tests Confirm Significant Capacity Increase

22 Clarifier Capacity Determined by SLR, Resulting in Excessive Sludge Blanket Depth

23 Influent ML Mixing with Settled Sludge Demonstrated by Computational Fluid Dynamic (CFD) Analysis

24 Conventional Parameters Also Maintained During Wet Weather Periods Parameter Average Concentration Median Concentration Range TSS (mg/l) Ammonia (mg-n/l) Total Phosphate (mg-p/l)

25 Secondary Clarifier Capacity Determined by Sludge Loading and Characteristics

26 Sludge Settling Characteristics Controlled by Bioreactor Configuration

27 Anoxic Selector Sized Based on Anoxic SRT SRT = 1-2 Days, Depending on Temperature Staging Similar to Aerobic Selector Possible 5 mg BOD 5 /mg NO 3 -N (8 mg COD/ NO 3 -N) Designed to Nitrify Staging Improves Selection Clarifier RAS WAS

28 Bio-P System without Nitrification Sized Using Anaerobic/Aerobic SRT SRT = 1-2 Days, Depending on Temperature, to Control Settleability SRT Increased to 2-3 Days for More VFAs Staging Possible SRT = 2-3 Days, Depending on Temperature, to Retain PAO s with No Nitrification Staging Improves Selection Clarifier RAS WAS

29 Bio-N&P Process with Sufficient Influent VFA s or Fermentation Anaerobic SRT = 0.5 Days Staging Possible Anoxic SRT 1 to 2 Days, Depending on Denitrification Needed Staging Possible Aerobic SRT as Needed to Nitrify Staging Improves Selection ARCY NRCY RAS WAS

30 Bio-N&P Process with Insufficient Influent VFA s Anaerobic SRT = 2-3 Days Staging Possible Anoxic SRT 1 to 2 Days, Depending on Denitrification Needed Staging Possible Aerobic SRT as Needed to Nitrify Staging Improves Selection ARCY NRCY RAS WAS

31 Sludge Settling Characteristics Controlled by Bioreactor Configuration

32 Numerous Automatic Control Options Exist: DO Control DO Feedback Control DO Feedforward/Feedback Control Ammonia-Based DO Control Chemical Phosphorus Metal Salt Addition Control Feedback and Feedforward/Feedback Control Chemically Enhanced Primary Treatment (CEPT) Control Automatic SRT Control Chlorination Control Residual Chlorine Oxidation/Reduction Potential (ORP) Control

33 Fundamental Understanding of Wastewater Characteristics and Processes Frames Opportunities and Constraints

34 C O D R e d u c t io n, % Recognizing Differences in Primary and WAS Can Result in Different Solutions Primary Sludge: Digests Faster and More Completely Because Contains Little Biomass Dewaters Better, Because Contains Little Biomass % P rim a ry S lu d g e (In flu e n t B O D = 6.0 g /L ) Waste Activated Sludge: Digests Slower and Less Completely Because Contains Biomass Dewaters Poorer, Because Contains Biomass Sludge Hydrolysis Can Changes WAS Characteristics to be More Like Primary Sludge % P rim a ry S lu d g e % W A S (In flu e n t B O D = 5.5 g /L ) % W a ste A ctiva te d S lu d g e (W A S ) (In flu e n t B O D = 3.9 g /L ) S R T, d ay s From G. F. Parkin and W. F. Owen,. JEED, ASCE 112: , 1986.

35 Avoided Costs Can be More Important Than Resource Recovery Product Revenue Phosphate Recovery Provides Excellent Example: Struvite Scaling Problems Addressed Improved Sludge Dewatering Phosphorus Limits on Land Application Relaxed

36 Carbon Diversion is Required to Achieve Oxygen Savings From Short-Cut Nitrogen Removal and Annamox As Long as Influent Biodegradable Organic Matter is the Carbon Source for Denitrifcation: NH 3 N 2 Valence Change: -3 0 = +3 Net Oxygen Required mg O 2 /mg NH 3 -N Biodegradable Organic Matter in Excess of That Needed for Denitrification Must Still be Oxidized Daigger, G. T., WER, 86(2), , 2014.

37 Maximizing SRT and Minimizing DO Minimized Biosolids and Energy Requirements Contrary to Theory, Energy Requirements for Plants That Nitrify and Denitrify Can be Less Than Simple Secondary Treatment Added Environmental Benefits Include Nutrient Removal Nitrogen Removal Through Denitrification Biological Phosphorus Removal

38 Staged Anoxic/Aerobic Digestion with Pre- Thickening Saves Energy and Enhances Digestion Pre-Thickening Allows Heat of Oxidation to be Used to Maintain Temperature and Reduce Energy for Mixing Anoxic Operation Removed Nitrogen and Reduces Energy Requirements Stages Provides Superior Pathogen Destruction Temp (oc) VS Reduction (%) 20 1-Nov 1-Dec 31-Dec 30-Jan 1-Mar 31-Mar 30-Apr Date Daigger, G. T. and E. Bailey, WER, 72, (2000).

39 Residual Sludge Significantly Reduced by Separating Fibrous Material Approximately Half or More of Dry Solids Following Digestion Dewaters in Conventional Screenings Compactor to Around 40 % Dry Solids Consistency of Moist Paper Pulp Being Recovered for Potential Sale in Europe

40 Fundamental Understanding of Wastewater Characteristics and Processes Frames Opportunities and Constraints

41 Treatment Optimization: What s Possible Glen T. Daigger, Ph.D., P.E., BCEE, NAE Professor of Engineering Practice President and Founder, One Water Solutions Presented at Michigan Water Environment Association Annual Process Seminar: Using Technology to Get More Out of Your Facility Eagle Eye Banquet Facility Chandler Rd. East Lansing, MI November,