Tales from the Field: Troubleshooting Denitrification

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Julius Owens
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1 Tales from the Field: Troubleshooting Denitrification OWEA Plant Operations Conference North Pointe Conference Center May 21, 2014 Jon van Dommelen Ohio EPA Compliance Assistance Unit

2 Denitrification

3 Denitrification

4 Denitrification Basics 1. Nitrate present 2. No dissolved oxygen present 3. Bacteria present 4. Soluble carbon present

5 Denitrification Basics 1. Nitrate present Nitrification will precede denitrification

6 Denitrification Basics 1. Nitrate present Nitrification will precede denitrification 2. No dissolved oxygen present There shouldn t be any DO in the sludge blanket in the clarifier

7 Denitrification Basics 1. Nitrate present Nitrification will precede denitrification 2. No dissolved oxygen present There shouldn t be any DO in the sludge blanket in the clarifier 3. Bacteria present Denitrifying bacteria will be present in the MLSS entering the clarifier

8 Denitrification Basics 1. Nitrate present Nitrification will precede denitrification 2. No dissolved oxygen present There shouldn t be any DO in the sludge blanket in the clarifier 3. Bacteria present Denitrifying bacteria will be present in the MLSS entering the clarifier 4. Soluble carbon present Carbon will be present as a result of long detention times in the clarifier sludge blanket Carbon will be present as a result of organic bleed through from the aeration tank

9 Denitrification

10 Remove any one of the denitrification criteria, And you inhibit denitrification No Nitrate High DO No Bacteria

11 But. Denitrification Basics What if you NEED to denitrify?

12 Land Application of Treated Wastewater

13 History of Land App Systems 1992 Ohio Supreme Court Ruled that alternatives to point source discharges must be considered 1993 Ohio EPA began to write rules 1996 Antidegradation rules stated that Nondegradation Options must be considered. Land Application Management Plans (LAMPs) began implementation for Non-Discharging Systems.

14 Recent History of Land App Systems 2007 New Rules come out. NPDES permits or LAMPs for land application of treated wastewater systems Implementation of the new Rules begins 2014 Systems are now demonstrating what is necessary to attain 10 mg/l TIN

15 Today New WWTPs with Land Application must be designed to treat to 10 mg/l TIN, WWTPs that were not designed to treat to 10 mg/l TIN are faced with interim NPDES limits or LAMPs and required to submit a plan indicating how the limitation will be met.

16 Today So how hard is it to meet a TIN limit of 10 mg/l?

17 Firestone Trace WWTP

18 Firestone Trace WWTP

19 Firestone Trace WWTP

20 Firestone Trace WWTP

21 Firestone Trace WWTP

22 Firestone Trace WWTP

23 Firestone Trace WWTP

24 Firestone Trace WWTP

25 Firestone Trace WWTP Design Flow MGD Initial Flow MGD Current Flow MGD Effluent Limits: NH 3 -N: 5 mg/l TIN 10 mg/l CBOD 5 10 mg/l TSS 12 mg/l

26 Firestone Trace WWTP EQ ANX AT 1 AT 2 AT 3

27 Firestone Trace WWTP

28 6/1/2009 6/9/2009 6/17/2009 6/25/2009 7/3/2009 7/11/2009 7/19/2009 7/27/2009 8/4/2009 8/12/2009 8/20/2009 8/28/2009 9/5/2009 9/13/2009 9/21/2009 9/29/ /7/ /15/ /23/ /31/ /8/ /16/ /24/ /2/ /10/ /18/ /26/2009 1/3/2010 1/11/2010 1/19/2010 1/27/2010 2/4/2010 2/12/2010 2/20/2010 2/28/2010 3/8/2010 3/16/2010 3/24/2010 4/1/2010 4/9/2010 4/17/2010 4/25/2010 5/3/2010 5/11/2010 5/19/2010 5/27/2010 6/4/2010 6/12/2010 6/20/2010 6/28/2010 7/6/2010 7/14/2010 7/22/2010 7/30/2010 8/7/2010 8/15/2010 8/23/2010 8/31/2010 9/8/2010 9/16/2010 9/24/ /2/ /10/ /18/2010 Firestone Trace WWTP 45 Firestone Trace WWTP Total Inorganic Nitrogen 6/1/ /19/ TIN

29 Firestone Trace WWTP October 19, 2010 Ammonia Nitrate Alkalinity Centrifuge Spin Raw (EQ) Anoxic Tank Aeration Tank 3 < NO3-N Recycle Pump Clarifier (North) < Clarifier (South) < Clarifier Effluent RAS (North) RAS (South) UFFM Effluent < Sand Filter Effluent <

30 Firestone Trace WWTP Conclusion: No nitrate reduction in Anoxic Tank No alkalinity increase in Anoxic Tank Anoxic Tank NOT Anoxic

31 Firestone Trace WWTP

32 Game Plan: Firestone Trace WWTP Turn off the NO 3 -N Recycle Pump Pump rate: 95 gpm Rely on Geyser Pump for NO 3 -N Gain detention time in Anoxic Tank Sample EQ basin for cbod Determine carbon load to drive denite STEP collection system

33 Firestone Trace WWTP November 29, 2010 Ammonia Nitrate Alkalinity Centrifuge Spin Raw (EQ) Anoxic Tank Aeration Tank NO3-N Recycle Pump Clarifier (North) Clarifier (South) Clarifier Effluent RAS (North) RAS (South) UFFM Effluent Sand Filter Effluent

34 Game Plan: Firestone Trace WWTP Deploy Datasondes to Monitor Tank Status EQ Basin: Anoxic Tank: Aeration Tank: Dosing Tank S::can (COD) YSI (DO, ORP, ph, Temp) YSI (DO, ORP, ph, Temp) S::can (NO3-N, TSS)

35 Firestone Trace WWTP

36 Firestone Trace WWTP

37 Firestone Trace WWTP Date Time Site COD, mg/l Standard, 1,000 mg/l Dec-10 9:00 EQ Effluent Dec-10 9:30 EQ Effluent Dec-10 10:15 EQ Effluent Dec-10 10:55 EQ Effluent Dec-10 13:05 EQ Effluent Dec-10 11:00 Anoxic Effluent (centrate) (high range) 48 11:00 Anoxic Effluent (centrate) (low range) 26 11:00 Anoxic Effluent (centrate) (low range) 28

40 Firestone Trace WWTP December 15 NH 3 -N NO 3 -N T. Alk Spin Raw Influent Anoxic Aeration Tank Aeration Tank Clarifier (N) Clarifier (S) RAS (N) RAS (S) Final Effluent

41 Dosing Tank NO3-N (mg/l) 25 Firestone Trace WWTP Dosing Tank NO3-N (mg/l) 12/8/ /15/ Dosing Tank NO3-N (mg/l)

42 Firestone Trace WWTP Data Mismatch? Chemical analysis indicated compliance S::can data indicated noncompliance Which is right?

43 Firestone Trace WWTP Lab results indicated that the S::can was right What was wrong with the test kits? Hach literature noted a Chloride interference at concentrations > 100 mg/l Monitoring well data indicated that the Chloride concentration exceeded 100 mg/l and often exceeded 500 mg/l Alternate method (Chromotropic Method) noted Chloride interference > 1000 mg/l

44 Firestone Trace WWTP January 5, 2011 NH 3 -N NO 3 -N T. Alk Spin Raw Influent (cr) 3.9(cd) 440 Anoxic (cr) 4.6(cd) Aeration Tank 1 (operating anoxically) (cr) 3.9(cd) Aeration Tank (cr) 7.0(cd) Clarifier (N) (cr) 6.9(cd) Clarifier (S) (cr) 5.1(cd) RAS (N) (cr) 6.8(cd) RAS (S) (cr) 4.7(cd) Final Effluent (cr) 6.6(cd) Dosing Tank 13.7 (cr) 4.2(cd) 200

45 NO3-Neq (mg/l) CODeq (mg/l) 26 Firestone Trace WWTP Dosing Tank Nitrate Concentration Equalization Basin COD Concentration 12/15/ /05/ NO3-Neq (mg/l) EQ CODfeq (mg/l) 144 per. Mov. Avg. (EQ CODfeq (mg/l))

46 Firestone Trace WWTP 1/5/2011 Nitrates are still high (anoxic and effluent) Influent COD is low Aeration tanks are very aerobic (NH3-N ~ 0) Expand the Anoxic Tank?

47 Firestone Trace WWTP

48 Firestone Trace WWTP

49 Firestone Trace WWTP

50 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 0:00:00 EQ CODfeq (mg/l) Dosing Tank NO3-Neq (mg/l) 900 Firestone Trace WWTP s::can Data 01/05-01/ EQ CODfeq Dosing Tank NO3-Neq

51 Firestone Trace WWTP Continued to run with two anoxic tanks for through the summer of 2011 Flirted with Noncompliance for TIN all summer Pretty certain that carbon was the limiting factor

52 Firestone Trace WWTP 9/12/2011 A 55 gallon drum of Glycerin began to drip into the Anoxic Tank

53 Firestone Trace WWTP

54 Firestone Trace WWTP

55 9/12/ /3/ /24/ /14/ /5/ /26/2011 1/16/2012 2/6/2012 2/27/2012 3/19/2012 4/9/2012 4/30/2012 5/21/2012 6/11/2012 7/2/2012 7/23/2012 8/13/2012 9/3/2012 9/24/ /15/ /5/ /26/ /17/2012 1/7/2013 1/28/2013 2/18/2013 3/11/2013 4/1/2013 4/22/2013 5/13/2013 6/3/2013 6/24/2013 7/15/2013 8/5/2013 8/26/2013 9/16/ /7/ /28/ /18/ /9/ /30/2013 1/20/2014 2/10/2014 3/3/2014 3/24/2014 4/14/ Firestone Trace WWTP Effluent Total Inorganic Nitrogen Invidiual Samples (2 per month) 9/12/2011-4/30/ TIN (mg/l)

56 Oct-11 Nov-11 Dec-11 Jan-12 Feb-12 Mar-12 Apr-12 May-12 Jun-12 Jul-12 Aug-12 Sep-12 Oct-12 Nov-12 Dec-12 Jan-13 Feb-13 Mar-13 Apr-13 May-13 Jun-13 Jul-13 Aug-13 Sep-13 Oct-13 Nov-13 Dec-13 Jan-14 Feb-14 Mar-14 Apr Firestone Trace WWTP Monthly Total Inorganic Nitrogen 9/2011-4/ TIN (mg/l)

57 Firestone Trace WWTP Optimize Anoxic Zone Control Nitrate Recycle Control Soluble Carbon Process Control Anoxic Tank NH3-N and NO3-N Aeration Tank NH3-N and NO3-N

58 Process Control Flow Chart for Denitrification in Anoxic Tank Clarifier Effluent Ammonia and Nitrate Test Ammonia Low Nitrates Low Ammonia Low Nitrates High Ammonia High Nitrates Low System in Compliance Check Anoxic Tank Nitrates Incomplete Nitrification Nitrates High Increase Soluble Carbon Feed Or Reduce Nitrate Recycle Pump Rate Nitrate Low Increase Nitrate Recycle Pump Rate Check and Correct Nitrification Inhibition: Low DO Low Alkalinity Low Temp Low MLSS Low Time

59 Tartan Fields WWTP Typical Extended Aeration WWTP Designed for ~ 160,000 gpd 3 Pass Aeration Tanks, 2 Tanks in Operation Non-discharging system with Spray Irrigation LAMP for 10 mg/l TIN NOT DESIGNED TO DENITRIFY

60 Tartan Fields WWTP

62 Tartan Fields WWTP

63 Tartan Fields WWTP

66 3/28/2013 3/29/2013 3/30/2013 3/31/2013 4/1/2013 4/1/2013 4/2/2013 4/3/2013 4/4/2013 4/5/2013 4/6/2013 4/6/2013 4/7/2013 4/8/2013 4/9/2013 NH3-N, NO3-N (mg/l) 45 Tartan Fields WWTP VARiON Trial First Pass NH3-N and NO3-N 03/28/ /09/ First Pass NH3-N First Pass NO3-N

67 3/28/2013 3/29/2013 3/30/2013 3/31/2013 4/1/2013 4/1/2013 4/2/2013 4/3/2013 4/4/2013 4/5/2013 4/6/2013 4/6/2013 4/7/2013 4/8/2013 4/9/ Tartan Fields WWTP VARiON Trial Final Pass NH3-N and NO3-N 03/28/ /09/ AT Eff AT Eff NO3-N

68 Tartan Fields WWTP Anoxic Tank Setup Anoxic Mixer RAS only for Nitrate Recycle Raw Wastewater only for Soluble Carbon Good Process Control by Operators Cycling Aeration On/Off to enhance Denite Cycled air for a year to try to meet 10 mg/l TIN

73 13:59 17:19 20:39 23:59 3:19 6:39 9:59 13:19 16:40 20:00 23:20 2:40 6:00 9:20 12:40 16:00 19:20 22:40 2:00 5:20 8:40 12:00 15:20 18:40 22:00 1:20 4:40 8:00 11:20 14:40 18:00 21:20 0:40 4:00 7:20 10:40 14:00 17:20 20:40 0:00 3:20 6:40 10:00 13:20 16:40 20:00 23:20 2:40 6:00 9: Tartan Fields WWTP Anoxic Tank NH3-N and NO3-N April 30 - May 7, /30/2014 5/1/2014 5/2/2014 5/3/2014 5/4/2014 5/5/2014 5/6/2014 5/7/2014 AX - NH4-N AX - NO3-N

74 13:59 17:19 20:39 23:59 3:19 6:39 9:59 13:19 16:40 20:00 23:20 2:40 6:00 9:20 12:40 16:00 19:20 22:40 2:00 5:20 8:40 12:00 15:20 18:40 22:00 1:20 4:40 8:00 11:20 14:40 18:00 21:20 0:40 4:00 7:20 10:40 14:00 17:20 20:40 0:00 3:20 6:40 10:00 13:20 16:40 20:00 23:20 2:40 6:00 9: Tartan Fields WWTP Aeration Tank NH3-N and NO3-N April 30 - May 7, /30/2014 5/1/2014 5/2/2014 5/3/2014 5/4/2014 5/5/2014 5/6/2014 5/7/2014 AT - NH4-N AT - NO3-N

78 Tartan Fields WWTP

79 Denitrification How hard is it to denitrify to 10 mg/l TIN?

80 Denitrification How hard is it to denitrify to 10 mg/l TIN? Control of the In-tank Environments is Essential

81 Denitrification How hard is it to denitrify to 10 mg/l TIN? Nitrate control

82 Denitrification How hard is it to denitrify to 10 mg/l TIN? Nitrate control Carbon control

83 Denitrification How hard is it to denitrify to 10 mg/l TIN? Nitrate control Carbon control Anoxic Control

84 Denitrification How hard is it to denitrify to 10 mg/l TIN? Nitrate control Carbon control Anoxic Control Aerobic Control

85 Denitrification Sometimes it is easy. sometimes it is trickier

86 Thank You