1. Innovations in Oxidation Technologies to treat difficult wastewaters Dr Peter Barratt Business Manager Environmental & Clean Technology Air Products (Europe)

2. 2 TNAV April 2005 Oxidation: The range of technologies 1234510 Organic Component Component Non- or poorly- biodegradable Biodegradable Ozone&Biological ThermalWetOxidation Incineration Aerobic Biological Stabilizationor Thermal Wet Oxidation AerobicBiological Organics Concentration (%) Requiring Destruction Ozone

3. 3 TNAV April 2005 High Purity Oxygen in Water for Aerobic Biology… why? Increased Saturation Concentration (C s ) –Oxygen in Air=9.1mg/l @ 20 o C –Oxygen=43 mg/l @ 20 o C Rate of Oxygen Mass Transfer –dC/dt = K L a (C s - C) –Pure oxygen maximises the oxygen deficit, so oxygen dissolves faster Process benefits –Microbes enjoy well oxygenated conditions

4. 4 TNAV April 2005 Treated water Excess Sludge Clarifier Feed Mixed Liquor or “Sludge” Returned Activated Sludge (RAS) Settled Sludge The Activated Sludge Process

5. 5 TNAV April 2005 Treated water Excess Sludge Clarifier Feed Mixed Liquor or “Sludge” Returned Activated Sludge (RAS) Settled Sludge The Activated Sludge Process OXYGEN

6. 6 TNAV April 2005 Pure Oxygen Classical Oxygenation by sidestream oxygen injection Recirculation Pump Activated Sludge Basin Water Intake Secondary Ejector Venturi-type device The OXY-DEP ® process Typically from Liquid Oxygen

7. 7 TNAV April 2005 Paper Industry lagoon

8. 8 TNAV April 2005 Technology –Oxygen generator (Vacuum Swing Absorption) linked to a low energy mixer –Standard sizes: 150 lpm(262kg/d) 500 lpm(875kg/d) 2800 lpm(5000kg/d) –Simplicity and cost in line with aeration –Process benefits of oxygen New development OXY-DEP ® VSA On-site generated oxygen

9. 9 TNAV April 2005 OXY-DEP ® VSA OXYGEN GENERATOR MIXER-OXYGENATOR

10. 10 TNAV April 2005 Aerobic Biological Treatment Aeration Typically 1 - 2kgCOD/m 3 /day –MLSS 1.5 – 5g/l Up to 0.5kgNH 3 -N/m 3 /day Oxygenation High Rate Biological Treatment processes –Typically 2 – 5kgCOD/m 3 /day MLSS 3 – 20g/l –Up to 5kgNH 3 -N/m 3 /day

11. 11 TNAV April 2005 OXY-DEP ® MB Process Feed Wash tank Effluent OXY-DEP reactor Membrane O 2 Inlet

12. 12 TNAV April 2005 OXY-DEP ® MB benefits Refractory COD is treatable High rate system –Above 30kgCOD/m 3 /day Low waste sludge production rate –zero in 3 months (rendering) Provides potentially re-usable water

13. 13 TNAV April 2005 Oxygen - common uses in aerobic biological treatment Increase treatment capacity of an existing aerated plant Reduce odours, foams and aerosols Cater for peak organic and ammonia loads as required Improve sludge quality Reduce regulatory risk and improve environmental image

14. 14 TNAV April 2005 Direct Ambient Oxidation Oxidation Processes Rising Main Injection (sewers) –avoids H 2 S and corrosion Sulphide (S - ) Oxidation –e.g. lagoons Ozone –Hard COD and colour removal O 2 & O 3

15. 15 TNAV April 2005 Ozone Unstable oxidant Generated on site Precursor to. OH Water treatment In conjunction with biological treatment

16. 16 TNAV April 2005 CHEMOX Reactor for O 3

17. 17 TNAV April 2005 CHEMOX - landfill leachate CHEMOX 1.8 O 3 :COD ratio* 4 hours HRT 500 mg/l COD in <150 mg/l COD out 4 kWh/kgO 3 Power diss Existing Plant Existing Plant > 2.2 > 2.2 10.3 hours 10.3 hours 500 mg/l 500 mg/l <150 mg/l <150 mg/l 8 kWh/kgO 3 8 kWh/kgO 3 * : ozone applied/COD removed

18. 18 TNAV April 2005 CHEMOX - landfill leachate CHEMOX 1.8 O 3 :COD ratio* 4 hours HRT 500 mg/l COD in <150 mg/l COD out 4 kWh/kgO 3 Power diss Existing Plant Existing Plant > 2.2 > 2.2 10.3 hours 10.3 hours 500 mg/l 500 mg/l <150 mg/l <150 mg/l 8 kWh/kgO 3 8 kWh/kgO 3 * : ozone applied/COD removed COST ADVANTAGE 17% lower in capital 29% lower in operation

19. 19 TNAV April 2005 Other Ozone Applications Sludge solids oxidation –Activated sludge in-process Pathogen removal in reused water Alternative clean oxidant in chemical synthesis Selective destruction of problem bacteria e.g. bulking

20. 20 TNAV April 2005 Oxygen reuse technology after ozone production Normally, conversion of O 2 to O 3 is 6% to 12% by weight. Therefore: –Oxygen off-gas use in other processes –Long Loop Recycle (LLR) –Short Loop Recycle (SLR) O 2 and O 3 separated after the ozoniser, and O 2 recycled to produce O 3 98% conversion of O 2

21. 21 TNAV April 2005 SLR Benefits - example Straight Through Total Oxygen Power Capital SLR Total 40% Savings 15% Savings 481216 Ozone Concentration [wt%] $0.50 $1.00 $2.00 $2.50 Cost

22. tell me more www.airproducts.com Please see our web-based Wastewater Treatment Plant Risk Assessment tool