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Advances in Leachate Management Research to Address Emerging Concerns UV Interference

Advances in Leachate Management Research to Address Emerging Concerns UV Interference. Stephanie C. Bolyard, PhD Research and Scholarship Program Manager April 5, 2017 NC SWANA 2017 Spring Conference . Emerging Concerns. Near Term Longer Term. Color UV transmittance (POTW) Nutrients

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Advances in Leachate Management Research to Address Emerging Concerns UV Interference

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  1. Advances in Leachate Management Research to Address Emerging Concerns UV Interference Stephanie C. Bolyard, PhD Research and Scholarship Program Manager April 5, 2017 NC SWANA 2017 Spring Conference 

  2. Emerging Concerns Near TermLonger Term • Color • UV transmittance (POTW) • Nutrients • Refractory Dissolved Organic Nitrogen (rDON) • Total Dissolved Solids/ Chlorides • Refractory COD • Arsenic • Emerging contaminants • Boron, PFCs, future unknowns • Pharmaceutical and Personal Care Products (PPCPs) • Nano-particles • Tritium Source: EREF Summit on Leachate Management

  3. Inhibition of UV Transmittance • In 2010 there was an estimated 7.1 billion gallons of leachate generated • Leachate disposal to POTWs can be a cost effective disposal option • But organics in leachate can interfere with downstream UV disinfection

  4. Nutrient Management • Leachate has a high concentration of nitrogen requiring treatment. • Existing technologies utilize biological treatment to oxidize ammonia-N to N2. • Numeric Nutrient Criteria may lower the total nitrogen and phosphorus limits. MSW Landfill discharged 5 tons of nitrogen in one month

  5. Leachate Management Research • Development of a Strategy for the Treatment of Landfill Leachates (Virginia Tech) • Approaches to Mitigation of Landfill Leachate‐Induced UV Transmittance Impacts (Montclair State) • Developing Strategies to Recover and Treat Nutrients in the Landfill Leachate (University of Utah and University of Central Florida)

  6. Minimizing Inhibition via Pre-Treatment Knowledge Gaps What leachate characteristics cause UV interference? Suspect small size organics (e.g. humics) may be the culprit How does variation in leachate characteristics affect UV interference? Leachate from different landfills will vary and influence the extent of interference How can leachate be treated to remove constituents causing UV interference? Develop a recommended pre-treatment strategy

  7. Initial Leachate Characterization Characterized particulate size fractionation and compared against: Micro-filtration (0.1 µm – 1 µm) Ultra-filtration (1 kDa-100 kDa) Nanofiltration (200 Da-1 kDa) Reverse Osmosis (< 200 Da) UV absorbance is not the same as color! Salts and Metal Ions Virus Bacteria 500Da 1kDa 3kDa 5kDa 1kDa 30kDa 100kDa .22um .45um 1.5um Raw

  8. Size Fractionation Observations Organic carbon particulates in leachate are very small Less than 3,000 kDa (bacteria) Most less than 100 kDa (viruses) Suggests physical/chemical methods of treatment (e.g. filtration, coagulation) will NOT work well Some success potentially with nanofiltration More success with reverse osmosis

  9. UV Transmittance for Different Leachates Leachate volumes as low as 1 – 4% of total volume treated by a POTW can significantly hinder UV disinfection (Zhao) Field studies by Bolyard and Reinhart, (2015) found that a leachate contribution of 0.59-1.1% can interfere with UV disinfection.

  10. Treatment Methods Evaluated

  11. Leachates Sampled • The leachate samples were collected from on-site municipal solid waste landfill leachate treatment facilities from • PA-1: (Active & Inactive) • PA-2: (closed in 2011) • PA-3: (closed in 2003) • NH: (Active) • "Treated leachates" were the samples collected from sequencing batch reactor (SBR)

  12. SBR Treatment Effect SBR treatment was successfully at removing DOC but UV absorbance still a challenge.

  13. Pretreatment and Co-Treatment SBR Only

  14. Combined Treatment

  15. Reducing UV-quenching substances in landfill leachate. • Submerged Anaerobic Membrane Bioreactor (AnMBR) with sequential thermophilic (55°C) and mesophilic digestion (37°C) (~7 months of treatment). • Both digestion processes work together to degrade different aromatic compounds responsible for UV interference

  16. Results Young Leachate Mature Leachate The absorbance decreased considerably following the AnMBR stage Long-term removal of over 60% of the total organic carbon from raw landfill leachates was observed using this two stage strategy, resulting in a reduction in UV absorbance by over 40%.

  17. Integrated “Recovery and Removal” Current paradigm • Anaerobic digester reject water and landfill leachate are two concentrated waste streams rich in N, P and C, and handled separately. • The current management schemes entirely focus on removal which can be limited by the presence of recalcitrant compounds and inhibitory concentrations. Proposed paradigm

  18. Experimental Approach Digester Reject Water Step 1: Nutrient recovery at different pHs + Leachate Step 2: Granular activated sludge process to remove carbon. Unlike in flocculated activated sludge processes, dense granules will be able to tackle toxics: Alternative: Use anaerobic process to recover carbon Step 3: Partial nitrification coupled with anaerobic ammonia oxidation to remove remaining nitrogen

  19. Preliminary Results Initial Concentration (mg/L) • Struvite Precipitation • Phosphorus removal 75% 9.21 mg/L • Ammonia removal 16% 474 mg/L • Biological treatment • Granular reactor • COD removal 42% 542 mg/L • Ammonia removal 15% 374 mg/L • Phosphorus removal 50% 2.30 mg/L • Single-stage partial nitrification/Anammox reactor • Ammonia removal 25% 318 mg/L

  20. Conclusions • On‐site leachate treatment combined with co‐treatment of sewage at POTWs is still necessary to address the UV transmittance challenges at POTWs. • Three on‐site treatment trains achieved an effluent UVT ≥ 65% when coupled with treatment at a POTW • SBR  coagulation  PAC adsorption • SBR  coagulation  Fenton • SBR  Fenton treatment

  21. Conclusions • Nutrient Recovery has the potential to be a revenue source and a means to improve the effectiveness of subsequent biological treatment.

  22. Acknowledgements • Yang Deng - Montclair State • Ramesh Goel - University of Utah • John Novak - Virginia Tech • Amy Pruden - Virginia Tech • Debra Reinhart - University of Central Florida

  23. Questions Stephanie C. Bolyard, PhD sbolyard@erefdn.org www.erefdn.org 2017 EREF Leachate Summit at WasteExpo May 8, 2017 New Orleans, LA The EREF Summit will bring together practicing engineers, academics, industry professionals, government personnel, and policy makers for in-depth discussions on topics related to landfill leachate treatment and management. https://erefdn.org/event/2017-eref-leachate-summit-wasteexpo/

  24. Nutrient Recovery Potential Landfill Solid waste • Complex blend of contaminants • Current approaches rely on “removal” Leachate • Significant concentration of nitrogen and carbon • How can we recover and treat using innovative approaches?

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