1. Ammonia Control for Landfill Leachate
NC SWANA ANNUAL CONFERENCE
Asheville, NC
April 6, 2017

2. Agenda SWANA Leachate Survey Ammonia Nitrogen Background
Effluent Limits
Conventional Treatment
Physical Treatment
Biological Treatment
Innovative Treatment

3. Q1: How is leachate presently managed at your landfill?
Answered: Skipped: 0

4. Q1: How is leachate presently managed at your landfill?
Answered: Skipped: 0

5. Q2: If discharged to POTW, how is it conveyed?
Answered: Skipped: 67

6. Q2: If discharged to POTW, how is it conveyed?
Answered: Skipped: 67

7. Q3: If discharged to POTW, what discharge limits must the leachate meet?
Answered: Skipped: 78

8. Q3: If discharged to POTW, what discharge limits must the leachate meet?
Answered: Skipped: 78

9. Q4: If pre-treated or treated on site, what discharge limits must the leachate meet?
Answered: Skipped: 130

10. Q4: If pre-treated or treated on site, what discharge limits must the leachate meet?
Answered: Skipped: 130

11. Why Control Ammonia?
Why removal ammonia? – A nutrient, can promote algae growth/algae blooms – Can exert oxygen demand in receiving waterways – Free or un-ionized fraction is toxic to aquatic life Ammonia in Landfills Ranges from 100 to 2,000 mg/L • In certain cases, effluent ammonia limits based on limiting oxygen demand in receiver, • More often, limits set based on toxicity to aquatic life • “Free” ammonia fraction is toxic: NH4+ NH3 +H+ – Chronic toxicity limit ~ 0.02 mg/L (after mixing in receiver) – Acute toxicity limit ~ 0.1 mg/L (at end of pipe) • Impacted by pH and temperature • At pH 7.5, 15oC, about 1% of TAN is NH3-N – So to achieve 0.1 NH3, need to be below TAN of 10 mg/L

12. Ammonia in Landfill Leachate – Physical Chemical
Breakpoint Chlorination
Air stripping
Ion exchange
Chemical Precipitation – Struvite
Transmembrane Chemical Sorption

13. Breakpoint Chlorination
Sodium hypochlorite/chlorine gas oxidizes ammonia

14. Air Stripping Simple Air Stripping Closed Loop Air Stripping
Pros: pH Adjust, Air Discharged to Atmosphere
Cons: Removal Efficiency Limited by Operating Temperature
Closed Loop Air Stripping
Pros: No Air Emissions by Scrubbing,
Conservation of Energy
Cons: Higher Initial Cost and Operations,
Disposal of Concentrated Ammonia Sulfate
Thermal Destruction Air Stripping
Pros: Oxidizer Controls Ammonia Release,
No Concentrated Ammonia Sulfate Disposal
Cons: Higher Initial Costs and Operating Costs

15. Air Stripping NH3 +H2O= NH4+ +OH- Controlled by pH and temperature
High volumes air required
Temp >150 deg F and pH 10 removes 80% ammonia – higher temp/pH = greater removal
Scaling/foaming
Advantages
Disadvantages
Possible recovery of ammonia for resale
Potentially very high capital and O&M costs
Most efficient at higher ammonia concentrations
Scaling and corrosion are issues
 Possibly cost effective with high ammonia levels and partial treatment sites
Large quantities of acids and caustic chemicals required
 High Efficiencies reported – 85% to 99.5%
Chloride levels would be raised and may pose a discharge issue
High labor costs have been reported
Air pollution control may be an issue

16. Selective Ion Exchange
Naturally occurring zeolites or manufactured products
clinoptilitie or polyermic exchangers - Dowex 50w-x8 or Purolite MN500
10-20 mg/g NH4+
Use as a polishing after biological treatment?
Regenerant management – Treat or dispose as solids?
Volumes of high strength regenerant require treatment – biological?
Advantages
Disadvantages
Acts as a polishing step to remove residual ammonia
Untried at full scale in leachate treatment systems
Requires installation of Ion Exchange Columns, pumping systems, regenerant chemical storage, regenerant flow processing by air stripping or electro-oxidation, biotreatment or possible sale of concentrated ammonia in regenerant.

17. Chemical Precipitation
Precipitation of NH4+-N by forming magnesium ammonium phosphate (MAP)
Advantages
Disadvantages
Installed ahead of SBR, may reduce ammonia and COD concentrations to be further treated
Large quantities of additional chemicals to be added
Requires installation of chemical storage, feed systems, rapid mix, and clarification stage
Untried at full scale in leachate treatment systems

18. Biological Treatment
Technologies
conventional activated sludge,
sequencing batch reactors,
membrane bioreactors,
aerobic lagoons,
trickling filters
constructed wetlands.
Uptake of ammonia during biological growth (heterotrophs vs. autotrophs)

19. Biological Nitrification
• Ammonia Reduction by Nitrification is a two- step reaction:
NH O2 +AOB = NO2 +2H++H20
NO2 +0.5O2 + NOB = NO3-
– Nitrifiers do not use organic carbon as basis for growth (CO2)
– Nitrification releases acid, use up alkalinity
– 4.57 g O2 consumed per g ammonia oxidized to nitrate (supply more! – keep DO 3-5 mg/L)
– Acid formed, consumes alkalinity, 7.14 g alkalinity per g NO3
– Nitrite intermediate almost never “stable”, nitrite oxidizers grow faster than ammonia oxidizers at typical leachate temperatures

20. Keys to Biological Nitrification
Alkalinity
– Alkalinity is the carbon source for nitrifier growth
– Do not want to go below 50 mg/L as CaCO3, or pH
– For 1,000 mg/L ammonia nitrified, require 200 mg/L alkalinity
• 7.14 x ~ 7,200 mg/L (can gain back with denitrification) pH
– Optimal pH for nitrification between
– pH below 6 can lead to inhibition
Low Oxygen
– Nitrifiers are strict aerobes, inhibited at very low DO levels (Filamentous/foaming issues)
– As long as DO > 2 mg/L, little impact on nitrifier growth rate
Inhibitions
Organic acids/metals/SRT
Temperature
Free ammonia toxicity

21. Biological Nitrogen Removal - Denitrification
Denitrification is defined as growth of bacteria when nitrate is used as the terminal electron acceptor:
Organic C + NO3 > Biomass +CO2 + N2
Different from aerobic growth in that nitrate is used instead of DO
Majority of heterotrophic bacteria in WW treatment can use both oxygen and nitrate
If oxygen is present, it will be used before nitrate
Oxygen inhibits denitrification – why would bugs try harder?
Reduces oxygens demand (energy!)/ returns alkalinity/ stable pH

22. Biological Nitrification
Advantages
Disadvantages
Most commonly used technology
Potentially costly capital
Operators usually familiar with the processes
High Energy Costs from oxygen demand
Can be effective with close operation
Susceptible to upsets
Detailed process controls needed
Sludge production to be managed

23. Innovative Ammonia Control
Short-Cut Ammonia Removal
Direct Ammonia Removal – deammonification
Anammox (Anaerobic Ammonia Oxidation)
Addition of Fixed Media (IFAS?)
Transmembrane Chemical Sorption
Aerobic Granular Sludge
Electro-Oxidation

24. Short Cut Ammonia Removal Deammonification/Anammox
Grows the anammox bacteria in gravity-separated granules. Hydroclone or high-rate clarifier settles granules, flushes out bacteria , keeps sludge age required for existing bacteria
DEMON
Oxidation of some ammonium to nitrite. Partial nitrification by Nitrosomonas;
Reduction of nitrite where ammonium is used as electron donor. Some nitrite is oxidized to nitrate. This reaction carried out by anammox bacteria =deammonification.
MBBR (three suppliers)
DeAmmon® process from Purac/Läckeby AB
ANITA™ Mox from AnoxKaldness/Veolia
Terra-N® process from Clariant/Süd-Chemie AG
Savings
Energy
Sludge Reduction
CO2 emissions

25. Process Overview - Anammox
Advantages
Disadvantages
60% savings in aeration energy
Very low growth rate (1/10th of nitrifiers)
No methanol feed -100% savings in supplemental carbon
Inhibited by oxygen
Successful European experience
Hard to start up
Difficult to maintain

26. IFAS Media Addition Addition can upgrade existing processes
Use in SBR or Aeration Basins
Increases MLSS
3,000 mg/L – doubles?
Can simultaneous nitrify and
denitrify, reduce or eliminate
methanol as carbon source

27. IFAS Addition to Activated Sludge/SBR
Advantages
Disadvantages
Increase ammonia removal and throughput, well established technology
Potentially costly capital
Less sensitive to upsets or process variations
Second aeration source under modules
Can be installed simply and quickly
Reduced sludge production

28. Transmembrane Chemical Sorption
Raise pH and drive ammonia across membrane – Reject sold as fertilizer? 95% removal
Liqui-cell Process by Membrana

29. Transmembrane Chemical Sorption
Acid solution removes ammonia gas from flow
Then sulfuric acid reacts to form ammonium sulfate
Ammonium sulfate can be sold as fertilizer
Untried with Leachate
Advantages
Disadvantages
Compact module design with Single step In-line processing
Untried at full scale in leachate treatment systems
Lab data – 95% ammonia removal
Manage concentrated stream with other technologies
 No air emissions
Adjust pH with high chemical cost, then neutralize
Possible cost recovery from fertilizer sale
What to do if can’t sell fertilizer?

30. Electro Oxidation – One Step
Direct electro-oxidation of ammonia (XOGEN Technology)
Low power
Releases nitrogen and hydrogen gas
Capture & use?
Modules in containers placed at end of existing process

31. Electro Oxidation – Two Step
A two step process, first, use ion exchange to concentrate the ammonium by electrodialysis.
Then, treat the concentrated ammonium stream with electro- oxidation (Enpar and Saltworks).
Capture ionic fluid – expensive
Planned to use solar power ?

32. Electro-Oxidation Technology
Advantages
Disadvantages
Ammonia Electrolysis-efficient for
removal of ammonia from leachate by direct conversion to nitrogen
Untried at full scale in leachate treatment systems
Lab data – 95% ammonia removal to 1 mg/L
Two step system more complicated, expensive ionic fluid
Generate hydrogen – use in CHP?
pH adjustment may be needed
Short detention time ~ 80 mg/L per minute
Air emissions considerations for Hydrogen – blending with large volumes air for LEL
Easy to operate – On/Off startup
Two Step has higher capital and O&M cost and more complex operation
No nitrous or nitric oxides produced
Long term operations unknown

33. Aerobic Granular Activated Sludge - Sequencing

34. Aerobic Granular Activated Sludge
Advantages
Disadvantages
Enhanced settling
One Supplier – Aqua-Aerobics
Reduced footprint – 75% possible
Long Startup or haul granules from others (Europe/ WI?)
Energy savings 0.5 mg/L DO
Untried with Leachate
Simultaneous nitrification Denitrification – Save methanol use

35. Summary Ammonia and nitrogen control becoming more frequent
Many ways to remove ammonia from leachate
Existing and Innovative technologies to consider
Costs depend on process, concentrations, effluent limits
Possible reuse or disposal of rejects
CAPEX versus OPEX
Recommend bench and pilot scale tests
Look beyond costs – space needed, utilities, ease of operation, speed of implementation needed
Part of Base Process or consider “bolt-on” technology.
Lots to consider!!

36. Ammonia Control for Landfill Leachate
Questions?
Ammonia Control for Landfill Leachate
Contact:
Ivan Cooper, PE, BCEE
Civil & Environmental Consultants, Inc.
1900 Center Park Drive
Charlotte, NC 29217
Tel: