Ganesh Rajagopalan Kennedy/Jenks Consultants Irvine, CA (949) 261 1577 rganesh@kennedyjenks

1. Impact of Nanomaterials During Wastewater Treatment Ganesh Rajagopalan Kennedy/Jenks Consultants Irvine, CA (949) 261 1577 rganesh@kennedyjenks.com Pacific Northwest Pretreatment Conference 10 September 2008

2. Nanotechnology is Here to Stay • Predicted market size > $1 trillion / Year by 2015 • Approach “Information Technology + Telecom”

3. Nanotechnology & Health Effects

4. Outline • What are Nanomaterials • Why Should We Care? • Where Do/Will They Come into Wastewater from? • Nanoscale Materials in Treatment Processes • Summary

5. Nanotechnology Definition • An emerging field that • creates and uses nanoscale material where the particle size is in the range of 1 to 100 nanometers (nm) in at least one dimension. • facilitates materials manipulationat the molecular level. National Nanotechnology Initiative

6. Nano = 10-9 meters Buckminster Fullerene – C60 “Buckyball” – 0.7 nm diameter Single Wall Carbon Nanotube

7. Relative Size Red Blood Cell D = 7,000 Nanometers Human Hair D = 50,000 Nanometers

8. So What if the Particles are Small? • High surface area • > 2 orders of µm particles • High reactivity • High electron density • Properties change at the nanoscale

9. Relative Size

10. Properties Change at Nanoscale • Thermal characteristics • Diffusion characteristics • Reactivity (e.g Gold) • Electronic properties • Optical properties (e.g. Gold, Carbon)

11. Gold Nanoparticles: 30 – 150 nm

12. When Released into Wastewater • Different Characteristics in Products Different Fate & Transport in WWTP • Existing Model Predictions May Not Be Valid

13. Manufacturing Pilot 2- 5 years R&D 20+ years ← Current market condition Time in Years Technology Development Cycles Nanotechnology Currently inYellow Zone Dollars

14. Potential Sources in WWTP (Products Containing Nanomaterials)

15. Nanotechnology Products

16. Emerging Contaminants PhACs – Pharmaceutically Active Compounds EDCs – Endocrine Disrupting Compounds Industrial Chemicals Nanomaterials PCPs – Personal Care Products

17. Personal Care Products

18. Market Information • Over 75 Products in Market • > 60% Products to Incorporate Nano • 9500 Products Can Potentially Use Nano Substitutes • > 50 Different Nanomaterials

19. Some Products and Nanomaterials

20. Agriculture, Pesticides and Biocides

21. Materials and Market • Nano Silver, Gold & Copper • Nano Silver is Among the Most Used • 67 of 381 Listed by Wilson Center

22. Products • Bactericides/Fungicides • Band-Aids • Air Fresheners • Washing Machines • Socks & Shoe liners

23. Nano Silver Issues • Nano Ag Significantly More Effective • Different Mechanisms Proposed • Swedish Wastewater Utilities Predict 2 - 3 Fold Ag Increase in Wastewater • Possible Biomass Inhibition and Resistant Strain Development • First Nanomaterial to be Regulated by USEPA

25. Cartoon from ETC Group Report

26. Food and Supplements

27. Cartoon from ETC Group Report

28. Nano in Automobiles

29. Some Other Products • Medical Industry • Diagnostic / Drug Delivery • Semiconductor • CMP • Paints and Coatings • Nano Cerium and Metal Oxides • Batteries • Nano LiCo, Ni

30. Nanoparticles in Wastewater Treatment Processes

31. Potential Issues • How will nanomaterials Affect Existing Treatment Processes? • Can nanomaterials be removed in Treatment Plants?

32. A. Suspended Particles. Treatability predominantly controlled by physical characteristics > 1 m. B. Dissolved Chemicals. Treatability predominantly controlled by chemical characteristics Contaminants in Wastewater

33. Background • Particle Size Distribution is a Continuum

34. A. Suspended Particles. Treatability predominantly controlled by physical characteristics B. Nanoscale Particles. Treatability not well understood. Likely to combine & differ from, A & C. C. Dissolved Chemicals. Treatability predominantly controlled by chemical characteristics Contaminants in Wastewater - Revised

35. Monitoring Nanomaterials in WWTP • Differentiate Conventional and Nanomaterials • Nanomaterials Elusion in GC/MS • Sample Prep • Nanoparticles Counter • Coulter Counter • Malvern Zetasizer

36. Biogenic Nanoparticle Distribution in Secondary Effluent

37. “Calibration” of Biogenic Nanoparticles in Secondary Effluent

38. Primary Settling: With & Without Coagulant • Poor settling without coagulant • Biogenic Organics • No Systematic Data for < 500 nm • Removal of 100 nm Humic Substance Correlated Well with Charge Density of Polymer • Particle Size Impacts pHzpc of Titania • 3.6 nm : pHzpc 4.8 • 8.1 nm : pHzpc 6.2

39. Primary Settling – With & Without Coagulant • Aggregation of Mfgd Nanomaterials • Deviated from Micron & Nanocolloidal Particles • Highly Mobile near PZC • More Aggregation farther away • Likely to Impact Coagulation • Metal Oxide (@ 10 mg/l) Nanoparticles • ~ 60 % Removed by Coagulation • Additional 20% by Filtration

40. Primary Settling – With & Without Coagulant • Nanomaterials Complex with NOM • Functionalization May Limit Collision of Nanomaterials

41. Activated Sludge • No systematic study to date • 10% Removal of Nano Latex Beads in Biofilms • C60 (0.4-4 mg/l) Inhibited (Soil) Nitrate Reducers • Lots of unknowns • Attached to microbial flocs? • Transported across cell membranes? • Adsorb dissolved metals • +/- on activated sludge performance?

42. Granular Filtration • µm particles removed mainly by Interception, Sedimentation • Brownian diffusion likely to dictate nanoparticle behavior • Functionalization will Lower Retention

43. Granular Filtration • Few data for 1-100 nm particles • Tortuosity of Flow Path More Significant Than Porosity • 10 – 50% removal of 46 – 825 nm • Low <1 µm particles removal with • Increase of Filter media size • Filter ripening

44. Membrane Filtration • Theoretical Prediction • Critical Size for Fouling ~100 nm • Variation with Membranes & Nanomaterials • OCWD MF Studies • Max Flux Reduction by 200 to 3.5 nm • WWTP Effluent in UF • 100 to 200 nm fraction Caused Max Fouling • Cellulose Acetate Membrane & Nano Latex Beads • Influx Point at 500 nm

45. Nano Silica in MF/UF • Smaller Particles had Higher Porosity • 60 nm : 0.32 – 0.38 • 34 nm : 0.35 – 0.43 • Cake Porosity High in MF • Rate of Flux Drop High in MF

46. Other Treatment Processes • Electrocoagulation • Mostly Used in Semiconductor Industry • Appear to be effective for 200 nm particles • Ion Exchange • Used during Nanomaterials Synthesis • Not Studied during Wastewater Treatment • Disinfection • Not Evaluated

47. Regulatory Status • TSCA • Existing Vs “New” • Nanomaterials as “Significant New Use”?? • CWA • Can Potentially set NPDES, WQ Stds • SDWA • Can Set MCLs, MCLGs, BAT based limits • Nano silver regulated by FIFRA

48. Summary • There’s Plenty of Room at the Bottom - Richard Feynman (12-29-1959) @ Caltech • Applies to Nano in Wastewater Also

49. WEF TPU http://www.wef.org/ScienceTechnologyResources/TPUs/ New! Nanoparticles (May 2008) (Members) (Nonmembers) This Water Environment Federation (WEF) Technical Practice Update (TPU) provides one of the first overviews of the potential effects of manufactured nanomaterials in wastewater treatment plants. Nanotechnology refers to the emerging field that creates and uses nanoscale material (manufactured nanomaterial) where the particle size is in the range of 1 to 100 nanometers (nm) in at least one dimension. Nanotechnology facilitates manipulation of materials at the molecular level. Because of their extremely small size and their ability to be manipulated at the molecular level, nanomaterials exhibit novel properties and functions that differ from their conventional counterparts, such as micron suspended or dissolved materials (National Nanotechnology Initiative, 2007).

50. WEF TPU Co-Authors • Background :April Gu • Relevance to WW :Kathleen Sellers • What do We Know? • Potential Sources : Ganesh Rajagopalan • Analyses : Dermont Bouchard • Treatability : Ganesh Rajagopalan • Regulatory Status : Igor Linkov • Where are We Going?