Introduction. D1: Nitrification D2: Denitrification D3: N-DBPs NH 4 NO 3 NO 2. Precursors N-DBPs 2 NO N 2 O N 2

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1 Research Program D: Biological Management of Nitrogenous Chemicals in Small Systems: Ammonia, Nitrite, Nitrate, and N-Disinfection By-Products (N-DBPs) Mary Jo Kirisits, Jerry Speitel, Kerry Kinney, Michal Ziv-El, Emily Palmer, Ethan Howley, Abel Ingle, Ryan Howell University of Texas at Austin Dave Reckhow, Chul Park, Soon-Mi Kim University of Massachusetts (Amherst) Jess Brown, Carollo Engineers 1

2 Introduction Brief Description: Examine biological management of the nitrogenous contaminant grouping (ammonia, nitrite, nitrate, and N-DBP precursors) D1: Nitrification D2: Denitrification D3: N-DBPs NH 4 + NO 2 - NO 3 - NO - 3 NO - 2 NO N 2 O N 2 Precursors N-DBPs Anticipated target utility characteristics: Utilities with source water containing ammonia or nitrate Continuum of technology development: 2

3 D1: Nitrification Isolate and concentrate natural organic matter (NOM) for use in benchscale nitrifying filters Examine nitrification at the bench scale for different NOM sources Determine if production of soluble microbial products (SMP) can be leveraged to spur removal of trace organic contaminants (TrOC) via heterotrophs Examine ammonia and TrOC removal at the pilot scale 3

4 D1: Nitrification Natural Organic Matter (NOM) Isolation and Concentration Jonathan Herrboldt 4

5 Introduction Brief Description: Obtain a concentrated NOM solution for use in nitrification (and other) experiments. Process Step 1: NOM isolation Step 2: NOM concentration Materials Source: Ingenloff, 2011 Setup originally part of EPA-funded work to study treatment of stormwater runoff 5

6 NOM - Isolation Step 5.0-μm and 0.5-μm filters Reduces fouling of ion exchange resin and reverse osmosis (RO) membrane Filtrate contains dissolved organic carbon (DOC) Cation Exchange Resin Reduces fouling of RO membrane Removes undesirable constituents (e.g. Ca 2+, Mg 2+, etc.) Ion Exchange Tank Source: Ingenloff, μm Filter 5.0-μm Filter 6

7 NOM Concentration Step Reverse Osmosis NOM solution passed through RO membrane Permeate discarded ~ liters concentrated to ~ liters Permeate Flow R.O. Membrane Concentrate Flow Variable Flow Drive Feed Flow Source: Ingenloff,

8 Results: Surface Water Analyte Raw (mg/l) Concentrated (mg/l) DOC ~ * Cl NO NO PO Ca Mg K Na *Source: Austin Water Utility, 2015 Quarterly Water Quality Summary. 8

9 Results: Groundwater Analyte Raw (mg/l) Concentrated (mg/l) DOC Cl NO NO PO Ca Mg K Na >250 9

10 D1: Nitrification Removal of ammonia and trace organic contaminants in bench-scale drinking water nitrifying biofilters Michal Ziv-El 10

11 Two primary microbial processes in nitrifying biofilters, both require oxygen 1. Ammonia-Oxidizing Bacteria and Archaea (AOB and AOA) Autotrophic, slow growers, nonmotile. Nitrification: NH 4 + (Ammonium) NO 2 - (Nitrite) NO 3 - (Nitrate) 2. Nitrite-Oxidizing Bacteria (NOB) Biodegradable organic carbon (BDOC) CO 2 + NH + 4 biomass 3. Heterotrophic Bacteria Fast growers, produce significant biomass. Heterotrophs might help nitrifiers but also compete for oxygen, ammonia, and space in the biofilm. 11

12 Ammonia and trace organic contaminants (TrOC) in drinking water treatment plants Nitrification of ammonia in the distribution system has deleterious effects. TrOC (pharmaceuticals, personal care products, pesticides) occurrence increasing Due to population growth and direct potable reuse 12

13 Removal of TrOC in biofilters Sorption Biodegradation: TrOC concentrations 2-3 orders of magnitude less than biodegradable dissolved organic carbon (BDOC). Secondary utilization Co-metabolism 13

14 Study Objectives and Design 14

15 Study Objectives Assess in bench-scale nitrifying biofilters: (1) Impact of source of natural organic matter (groundwater versus versus surface surface water) water) on removal on removal of of ammonia. and TrOCs. (2) Changes over time to the microbial communities. (3) Robustness of nitrification and TrOC removal to perturbations. (4) Formation of N-DBPs. 15

16 Biofilter Set-up 16

17 Biofilter Set-up: Run 1 Water Source Surface water Groundwater Ammonia 1.5 mg-n/l TrOC 5 µg/l 10-minute simulated EBCT at full-scale in each biofilter GAC (AquaCarb 820) Sand (Ottawa Sand) 17

18 Suite of TrOC spiked to influent (500 ng/l each) TrOC Use/Type Chemical Class 2-MIB Taste and odor Geosmin Taste and odor Diclofenac Pharmaceutical/NSAID Phenylacetic acid Naproxen Pharmaceutical/NSAID Propionic acid Gemfibrozil Pharmaceutical/anti-convulsant Fibric acid derivative Atenolol Pharmaceutical/cardiovascular Isopropylamino-propanol derivative Estrone Pharmaceutical/hormone Aromatic C18 steroid Caffeine Food product Thiabendazole Pesticide/fungicide Benzimidazole DEET Pesticide Aromatic amide 18

19 Run 1: Impact of natural organic matter source on removal of ammonia 19

20 Water Quality Parameters Parameter Groundwater- Edwards Aquifer Surface Water- Lake Austin ph Alkalinity [mg/l as CaCO 3 ] Dissolved Oxygen [mg/l] Conductivity [μs] Hardness [mg/l as CaCO 3 ] Dissolved Organic Carbon [mg/l] Assimilable Organic Carbon [μg-c/l] NH + 4 [mg-n/l] (amended) NO - 2 [mg-n/l] NO - 3 [mg-n/l] PO 3-4 [μg-p/l]

21 Nitrification with Groundwater Feed Disturbance Ammonia removal complete and stable for groundwater with GAC but not with sand. 21

22 Impact of AOC Addition on Groundwater Nitrification AOC addition (75 μg-c/l) Even small increase in AOC affected nitrification, negatively in GAC and potentially positively in sand biofilters. 22

23 Nitrification with Surface Water Feed Disturbance Nitrification in GAC and sand were similarly unstable (clogging and DO limitation), but GAC was more robust after several disturbances. 23

24 Conclusions From Run 1 High concentrations of AOC in the surface water source will cause unstable nitrification. Simulate groundwater concentrations in reconstituted organic matter feeds. Sand biofilters resulted in low (groundwater) or unstable (surface water) nitrification, Sand is not a good no sorption control for TrOC. Use only GAC biofilters. 24

25 Run 2: Updated set-up, sampling plan, and current status 25

26 Biofilter Set-up: Run 2 Reconstituted organic matter (1 mg/l DOC) TrOC presence (5 µg/l) Ammonia presence (1 mg-n/l) Surface water Groundwater Yes Yes No Yes No 10 minute simulated EBCT at full-scale in each biofilter GAC (AquaCarb 820) 26

27 Experiment Stages and Sampling Plan Stages: 1) Inoculation with raw groundwater (2 weeks). 2) Acclimation to reconstituted waters (2 months). 3) Robustness tests (3 months). 4) Assess sorption versus biodegradation (1 week). Analytical analyses and frequency: Twice/week: NH 3 Weekly: NO 2-, NO 3-, ph, DO, turbidity, HPC Monthly: TrOC, DOC, AOC, N-DBPs. Microbial community analyses (DNA): Monthly: Fingerprint using MiSeq Illumina and abundances using qpcr a) Bacteria and Archaea 16S rrna gene. b) Ammonia oxidizer amoa gene. 27

28 Stage 1: Raw Groundwater Stage 2: Reconstituted Waters Nitrification Run 2 Contamination First Monthly Sampling Nitrification start-up was rapid and has been mostly stable for the 20 minute simulated EBCT. 28

29 D1: Nitrification Pilot Testing Jess Brown 29

30 Synergizing with WRF 4559: Simultaneous Removal of Multiple Chemical Contaminants using Biofiltration Eric Dickenson (SNWA) is the PI, Jess Brown involved as a Co-PI Task 1: Literature Review Task 2: CEC Indicator Compound Assessment Task 3: Biofiltration Pilot Testing (3 sites) Target Contaminants: TOC, NH 3, N-DBP precursors, taste & odor, pharmaceuticals and personal care products, Mn Evaluate impact of media type, EBCT, contaminant spiking, and upstream treatment Task 4: Full-scale Biofiltration Testing Task 5: Guidance Tool Development 30

31 Pilot Testing at Houston s East Water Purification Plant 31

32 Raw Water Blending 32

33 Flocculation & Sedimentation 33

34 Ozone Contactors & Filters 34

35 Scope of Work for Project D1 Leverage 6-mo biofiltration pilot study at Houston (in operation for 3 wk) Task 1: Microbial Community Analysis Task 2: Phosphatase Analysis Task 3: Extracellular Polymeric Substance (EPS) & Biomass Quantification Task 4: System Shutdown Robustness Tests (Phase 5 of Pilot Testing) Task 5: Distribution System Simulation Analytical work will be done at UT-Austin and UMass- Amherst Data shared freely between WRF and WINSSS Project D teams 35

36 D1: Nitrification Impact of Soluble Microbial Products on Trace Organic Contaminant Biodegradation Emily Palmer Research question: Do SMP produced by nitrifying bacteria aid in the removal of TrOC by heterotrophic bacteria? 36

37 Background SMP Definition: organic compounds produced during substrate metabolism and biomass decay Contain carbon and electrons Humic substances, proteins, and carbohydrates Size: <1 kda to >100 kda Produced by heterotrophic and autotrophic microorganisms Ni et al.,

38 SMP are biodegradable Nitrifying bacteria produce SMP Microbial community of reactor fed no organic carbon: 50% heterotrophs, 50% nitrifiers Heterotrophic microorganisms can survive on SMP produced by nitrifying bacteria Therefore, heterotrophs and nitrifiers have a symbiotic relationship Kindaichi et al.,

39 Hypothesis: SMP aids TrOC biodegradation Nitrifier SMP stimulates heterotrophs to utilize more complex carbons Leads to production of enzymes for complex carbon degradation TrOC are complex carbons as well Enzymes for SMP biodegradation also might degrade TrOC Additionally, SMP supplies heterotrophs with a carbon source 39

40 Experimental Method Produce nitrifier SMP Agitated at 125 RPM Air supplied Shielded from light 26 C ph maintained at

41 Experimental Method Produce nitrifier SMP [C] = 5.6 mg/l C 41

42 Experimental Method Produce nitrifier SMP Acclimate heterotrophs to simple (acetate) or complex (SMP) carbon source Spike TrOC Monitor TrOC degradation kinetics over time 42

43 Initial Experimental Design Four flasks: 1. SMP + heterotrophs 2. Acetate + heterotrophs 3. SMP + heterotrophs (autoclaved after acclimation) 4. SMP + Pseudomonas aeruginosa Acclimated to their respective carbon source for 2 weeks Spiked with geosmin and monitored for 1 week 43

44 Results Geosmin c/c Time (hours) SMP + heterotrophs Acetate + heterotrophs Killed control SMP + P. aeruginosa 44

45 Revised Experimental Matrix Flask # Carbon Source Inoculum Killed Control SMP Acetate Heterotrophs P. aeruginosa Nitrifiers Autoclave Azide Flask 1 X X Flask 2 X X Flask 3 X X X Flask 4 X X X Flask 5 X X Flask 6 X X Flask 7 X X X Flask 8 X X X Flask 9 X X X Flask 10 X X 45

46 D2: Denitrification Mitigation of Nitrite Accumulation in Denitrification Biofilters at Low Temperatures Emily Palmer Research question: Does micronutrient addition to denitrification biofilters ameliorate nitrite accumulation at low temperature? 46

47 Background Denitrification (NO 3 - NO 2 - N 2 ) affected by many factors Temperature outside of optimum range (25-35 C) Nitrite-reducing bacteria are more sensitive to low temperatures than are nitrate-reducing bacteria This can lead to nitrite accumulation. Maximum Contaminant Level: 1 mg/l NO 2- -N Nitrite reductase is iron- or copper-based 47

48 Current Bench-Scale Set-Up Two biofilters in series: 1.59-min EBCT (each) 0.77 gpm/ft 2 loading rate 3 ml/min flow rate 4.32 L/day Nitrogen tank Synthetic groundwater : 1 mg/l NO 3 - -N 4.5 mg/l acetic acid (110% stoichiometric dose) 48

49 Experiment Status Denitrification achieved Optimizing concentration of acetate to decrease backwash frequency Next Steps One biofilter moved to 25 C room Temperature lowered (5 C increments) to achieve nitrite accumulation Supplement influent with iron Send samples for N-DBP formation studies to UMass-Amherst 49

50 Outputs and Outreach Completed: Removal of ammonia and trace organic compounds in drinking water nitrifying biofilters: temporal variations in organic compound removal and microbial community structure, AWWA Biological Drinking Water Treatment Symposium; January Scheduled: Impact of soluble microbial products on trace organic contaminant removal from drinking water, TX Water; April Case Study: Ammonia and trace contaminant removal in bench- and pilot-scale biofilters: microbial community structures, robustness, and nitrogen disinfection byproducts, ACE, June Anticipated: White paper for WINSSS website, Fall Manuscripts for submission to a technical journal Nitrification (bench-scale) Fall 2016 Nitrification (pilot-scale) Fall 2016 N-DBPS, Spring 2017 Denitrification, Summer 2016 WINSSS Webinar Spring

51 Discussion 51