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Perchlorate Degradation in Bench- and Pilot-Scale Ex-situ Reactors

Perchlorate Degradation in Bench- and Pilot-Scale Ex-situ Reactors. Bruce E. Logan, Kijung Kim, Booki Min Department of Civil and Environmental Engineering The Pennsylvania State University, University Park, PA Email: Blogan@psu.edu Steven Price Camp, Dresser and McKee Email: prices@cdm.com.

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Perchlorate Degradation in Bench- and Pilot-Scale Ex-situ Reactors

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  1. Perchlorate Degradation in Bench- and Pilot-Scale Ex-situ Reactors Bruce E. Logan, Kijung Kim, Booki Min Department of Civil and Environmental Engineering The Pennsylvania State University, University Park, PA Email: Blogan@psu.edu Steven Price Camp, Dresser and McKee Email: prices@cdm.com B. Logan, Penn State University

  2. Perchlorate Degradation: Topics • Abundance of perchlorate degrading bacteria. • Bacterial isolate used in tests: KJ • Bench-scale reactors: Acetate H2 • Comparison of rates in bioreactors • Pilot-scale reactor test B. Logan, Penn State University

  3. Are perchlorate-respiring bacteria abundant in nature? B. Logan, Penn State University

  4. Wastewater Total cells = 8.9x107 per ml From: Wu et al. (2001) B. Logan, Penn State University

  5. Creek water Total cells: 4.9x105 per ml B. Logan, Penn State University From: Wu et al. (2001)

  6. Unexposed Soils The citrate sample was positive on the 3 other substrates as well B. Logan, Penn State University From: Wu et al. (2001)

  7. Unexposed Soils Many soils showed perchlorate degradation when a larger sample mass was used B. Logan, Penn State University From: Wu et al. (2001)

  8. Perchlorate-contaminated soil Previous exposure of a soil to perchlorate results in rapid Perchlorate degradation From: Wu et al. (2001) B. Logan, Penn State University

  9. PRM Abundance: observations • PRMs present in natural waters at ~1000/109 • PRMs in “pristine” soils, that have no evidence of perchlorate contamination: ~1/109 • At sites where perchlorate is present, have an abundant perchlorate reducing population,~100/109 B. Logan, Penn State University

  10. Perchlorate Degradation: Topics • Abundance of perchlorate degrading bacteria. • Bacterial isolate used in tests: KJ • Bench-scale reactors: Acetate H2 • Comparison of rates in bioreactors • Pilot-scale reactor test B. Logan, Penn State University

  11. Classification: Dechlorosoma sp. KJ Phylogentic analysis of KJ(courtesy of Dr. Ian Head, Univ. of New Castle) From: Logan et al. (2001) B. Logan, Penn State University

  12. ClO4- Acetate CO2, H2O, Biomass ClO3- Acetate CO2, H2O, Biomass ClO2- Acetate Cl- + O2 CO2, H2O, Biomass Perchlorate Reducing Pathway kP Chlorite and chlorate do not accumulate in water: kD>> kC > kP kC kD B. Logan, Penn State University

  13. KJ Perchlorate kinetics: Ks=33 mg/L (lactate grown cell suspensions) From: Logan et al. (2001) B. Logan, Penn State University

  14. Substrate kinetics: acetate From: Logan et al. (2001) B. Logan, Penn State University

  15. Substrate kinetics: acetate From: Logan et al. (2001) B. Logan, Penn State University

  16. Substrate kinetics: acetate From: Logan et al. (2001) B. Logan, Penn State University

  17. Kinetic constants for growth of KJ on acetate From: Logan et al. (2001) B. Logan, Penn State University

  18. Cell yield- KJ B. Logan, Penn State University From: Logan et al. (2001)

  19. Epifluorescent micrograph (1000 ) of KJ stained with acridine orange Overall Stoichiometry Without biosynthesis: acetate/perchlorate = 1:1 (mol/mol) CH3COO- + ClO4- 2HCO3- + H+ + Cl- With biosynthesis: acetate/perchlorate = 2.9:1(mol/mol) CH3COO- + 0.35ClO4- + 0.26NH4+ + 0.04H+ 0.26C5H7O2N (cells) + 0.7HCO3-+ 0.35Cl- +0.78H2O B. Logan, Penn State University

  20. Perchlorate Degradation: Topics • Abundance of perchlorate degrading bacteria. • Bacterial isolate used in tests: KJ • Bench-scale reactors:Acetate H2 • Comparison of rates in bioreactors • Pilot-scale reactor test B. Logan, Penn State University

  21. Acetate-Fed Sand Packed-bed Column Experiments Sampling from the side ports of the column B. Logan, Penn State University

  22. Acetate-fed Bioreactors • Columns: 14 cm or 28 cm long. • Mixed cultures: enriched on perchlorate (activated sludge samples) • Pure culture:Dechlorosoma sp. KJ • Feed:Artificial groundwater (AGW) containing 20 mg/L perchlorate and nutrients; water from the City of Redlands B. Logan, Penn State University

  23. Critical EBCT was 34 minutes. Mixed cultures(14 cm sand column) B. Logan, Penn State University From: Kim and Logan (2000)

  24. Critical EBCT was ~40 minutes. Mixed cultures(28 cm sand column) Startup B. Logan, Penn State University From: Kim and Logan (2000)

  25. Critical EBCT was ~2.1 minutes. Pure culture: KJ(28 cm-sand column) B. Logan, Penn State University From: Kim and Logan (2001)

  26. As EBCT decreased: Perchlorate was non-detectable for 84% of samples (n=147) Pure culture: KJ(28 cm-sand column) B. Logan, Penn State University From: Kim and Logan (2001)

  27. Reliability: After start up, perchlorate removal was stable at: 95% of time: <23 ppb 84% of time: <4 ppb Pure culture: KJ(28 cm-sand column) B. Logan, Penn State University From: Kim and Logan (2001)

  28. Perchlorate is completely removed using groundwater from Redlands site. Redlands WaterPure culture KJ, (28 cm-sand column) B. Logan, Penn State University From: Kim and Logan (2001)

  29. Perchlorate Degradation: Topics • Abundance of perchlorate degrading bacteria. • Bacterial isolate used in tests: KJ • Bench-scale reactors: Acetate H2 • Comparison of rates in bioreactors • Pilot-scale reactor test B. Logan, Penn State University

  30. Perchlorate reduction supported by Hydrogen gas B. Logan, Penn State University From: Miller and Logan (2000)

  31. Hydrogen Reactor • Column: 12.5 cm (10 mm packed), 2.5 cm diameter • Packing: 3 mm diameter glass beads (1200 m2/ m3) • Pumping Solution:740 g/L perchlorate in trace metal solution • Gas mixture:H2, 43 mL/min and CO2, 7.5 mL/min) • Operation period:145 days B. Logan, Penn State University

  32. Fixed film biohydrogen reactor (unsaturated flow) B. Logan, Penn State University

  33. Hydrogen Reactor Average detention times of 1.0-1.3 minutes B. Logan, Penn State University

  34. In: 740 110 g/L Out: 460 80 g/L Removal: 38%9% Hydrogen reactor performance B. Logan, Penn State University From: Miller and Logan (2000)

  35. Perchlorate Degradation: Topics • Abundance of perchlorate degrading bacteria. • Bacterial isolate used in tests: KJ • Bench-scale reactors: H2 Acetate • Comparison of rates in bioreactors • Pilot-scale reactor test B. Logan, Penn State University

  36. Reactor Kinetics: Removal Rates • Expect removal rate, R, is 1st-order with respect to perchlorate concentration. • Rate calculated as: • For 1st-order kinetics, use log mean perchlorate concentration B. Logan, Penn State University

  37. Perchlorate Bioreactor Rates(Data prior to 2001; Mixed cultures, organic substrates) Rate indicates first order kinetics with concentration From: Logan (2001) B. Logan, Penn State University

  38. HYDROGEN REACTOR H2 reactor rates are slightly higher than those in other types of reactors From: Logan (2001) B. Logan, Penn State University

  39. ALL PERCHLORATE BIOREACTOR REMOVAL RATE DATA(Sand Column Reactor Data) The pure culture rate is an order-of-magnitude greater than other rates at comparable perchlorate concentrations Pure culture (KJ) reactor Organic substrates; non-PSU studies All hydrogen reactor data (some is unpublished) PSU= Penn State Reactors Adapted from Logan (2001) B. Logan, Penn State University

  40. Perchlorate Degradation: Topics • Abundance of perchlorate degrading bacteria. • Bacterial isolate used in tests: KJ • Bench-scale reactors: Acetate H2 • Comparison of rates in bioreactors • Pilot-scale reactor test B. Logan, Penn State University

  41. Study Participants • Site: Redlands, California, Texas St well field • Engineering Firm: Camp, Dresser and McKee • Research Unit: The Pennsylvania State University • Funding Agency: American Water Works Association Research Foundation (AWWARF; via an EPA Grant) B. Logan, Penn State University

  42. Study site: City of Redlands Map from the University of Redlands website B. Logan, Penn State University

  43. Texas St. Site in Redlands has 24 GAC columns (shut down due to perchlorate breakthrough) B. Logan, Penn State University

  44. PERCHLORATE FIXED-BED BIOREACTOR Patent No. 6214607 B. Logan, Penn State University

  45. Pilot plant Specifications • Feed: groundwater, acetic acid, ammonium phosphate • Two bioreactors in parallel: • Sand • Plastic media • Monitoring: • flow, pressure, pH, dissolved oxygen, • Perchlorate, acetate, nitrate B. Logan, Penn State University

  46. Media Used in Two Reactors operated in parallel Sand (1 mm diameter) Tri-Pack Plastic Media B. Logan, Penn State University

  47. Raw water supply- Redlands Site B. Logan, Penn State University

  48. Bioreactors housed on site in a converted garage (Redlands, CA) B. Logan, Penn State University

  49. B. Logan, Penn State University

  50. Filter inlet controls B. Logan, Penn State University

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