OZONE OXIDATION ENABLES WATERS TO BE RE-USED

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1 OZONE OXIDATION ENABLES WATERS TO BE RE-USED VII ANQUE`S International Congress and Mid-term AquaFit4Use Conference Dr. Jörg Mielcke ( - WED)

2 Outline Requirements for waters to be re-used Concepts for waste water treatment Principle aspects using ozone for waste water treatment Principle aspects about process combination (treatment trains) - biology and oxidation - AOP treatment Large scale plants Cost situation Conclusions 2

3 Motivation 3

4 Recommend maximum levels of different parameters for industrial water re-use qualities Parameter (excerpt) High quality water textile industry Moderate quality water textile industry Low quality water textile industry Quality for sanitary paper paper industry Quality for cleaning water food industry Colour [mg/l Pt] none visible none visible none visible 20 COD [mg/l] ph Conductivity [µs/cm] Calcium [mg/l] Colony forming units [CFU/100ml] 100 (other more)

5 Treatment Concepts for Waste Water Reuse A-Carbon MF RO AOP: - UV / H 2 O 2 - UV / O 3 - O 3 / H 2 O 2 Drinking water Inlet Primary Biology Clarifier Disinfection (Optional) Outfall / River Conventional WW Treatment Ozone Bio/Filtration UV AOP: - UV / H 2 O 2 - UV / O 3 - O 3 / H 2 O 2 A-Carbon Reuse 5

6 Treatment steps for waste water and principle effects Primary treatment Biological treatment Clarifier/Filter Additional treatment Technique Flocculation Coagulation Sedimentation Filtration Activated sludge Fixed bed Different kind of reactors Sedimentation Sand filter Different membrane filters Membrane Ozone (AOP) UV A-carbon Effects Ozone Reduction of Toxicity Increase of BOD Disinfection effect e.g. on sand filter (reduction of threadworms) COD removal Persistant substances removal Disinfection Color, Odor Threadworms Effects UV Disinfection Photo-oxidation 6

7 Tool boxes for treatment concepts of WW MEMBRANE Waste Water Carbon OXIDATION Separation Recycling Biology In situ SEVERAL TREATMENT TRAINS POSSIBLE AquaFit4Use concept 7

8 COD elimination by Ozone - example - COD [mg/l] COD COD elimination COD Elimination [%] Ozone dose [mg/l] 0 8

9 Specific oxidation: e.g. Kresol degradation COD [mg/l] Kresol [mg/l] 2000 COD Kresol Ozone dose [mg/l] 0 9

10 General effects AOX- / COD- elimination Decolorisation Deodorisation Disinfection ozone dosage (g O 3 / m³) 10

11 Oxidation with OZONE / principle aspects Improvement of: BOD/COD-ratio flocculation / filtration ozone oxidation in waste water partial oxidation (cracking) Reduction of: color toxic compounds (e.g. EDC) odor (e.g. H 2 S) bacteria further COD reduction complete oxidation Mineralisation of: CKW s TOC 11

12 Biology - Ozone - basic effects COD hardly biodegradable COD biodegradable COD Ozone biological treatment plant Goal: Improve biodegradability 12

13 Treatment effects using Biology-Ozone raw water ozone treatment I biology ozone treatment II bio-filter ozone dosage: g/m³ g/m³ effects: no detoxification cracking effects reduction of : reduction of : reduction of : reduction of : - phenol - biol. COD - partly COD - COD/BOD COD reduction 0% - color - BOD color, odor, foam - odor removal disinfection specific compounds e.g. EDC 0% 5% 60% 80% 90% 13

14 Oxidation with OZONE / principle aspects Improvement of: BOD/COD-ratio flocculation / filtration ozone oxidation in waste water partial oxidation (cracking) Reduction of: color toxic compounds (e.g. EDC) odor (e.g. H 2 S) bacteria further COD reduction complete oxidation Mineralisation of: CKW s TOC 14

15 Oxidation: ozone and radical reaction + P O3 P ox + OH - OH + P P ox O 3 : OH: specific (direct ozone reaction) fast, not specific 15

16 How to create more Hydroxyl Radicals? In theory, there are several technologies that exist for advanced oxidation, (AOP) such as: - Hydrogen Peroxide + Ultraviolet Light - Hydrogen Peroxide + Ozone - Ozone + Ultraviolet These are the technical relevant ones Known methods, but not commercialized: - Titanium Dioxide + Ultraviolet Light - The photo-fenton Process (Fe(OH) 2 + hv Fe 2+ + OH) - Oxidation in combination with electrolysis - Various Catalytic Processes (oxidant chemical + catalyst) - 16

17 COD reduction with ozone and ozone/h 2 O COD [mg 02/L] O3/H2O2 O Dosage react [g/m³] 17

18 Ozone treatment key technique to process waste water for various targets 18

19 Scheme of an ozone system cooling water 5-32 C O 3 offgas air / O 2 5,5 kv feed gas ozone generator reaction tank energy (400 V) grounded electrodes 19

20 MWWTP Kalundborg, DK - start up: 02/2003 Target: COD removal; 1200 m³/h High input of industrial waste water COD(effluent biology): mg/l Ozone installation: 2 x 90 kg ozone/h Oxygen production onsite Off-gas for biology aeration Limit < 70 mg/l COD 20

21 Ozone - application for different water types Drinking water - Ozone ( pre- / main / post- ozonisation) reduction of: bacteria, THM precursors, taste&odor (and other goals) ozone dose: 0.5 to 5.0 g O 3 /m 3 Municipal waste water - pre treatment part stream or polishing final effluent reduction of: colored substances, AOX, phenols, PAH, COD, bacteria, pharmaceuticals, etc. ozone dose: 5.0 to 150 g O 3 /m 3 Industrial waste water - different combinations Ozone - BIO - Ozone - BIO reduction of: specific chemicals, color, COD, etc. ozone dose: 50 to 1000 g O 3 /m 3 21

22 Cost situation / example calculations necessary ozone dosage: - polishing effluent: 5 20 g/m 3 - slight COD reduction, decolourisation: g/m 3 - intensive COD reduction: g/m 3 cost for ozone production: Euro/kg ozone (invest ozone generation + operation no reaction system) end up in: - 5 g O 3 /m³ to 0.01 Euro/m 3-50 g O 3 /m³ to 0.10 Euro/m g O 3 /m³ 0.30 to 0.40 Euro/m g O 3 /m³ 1.5 to 2.0 Euro/m 3 22

23 Conclusions Oxidation for re-use? Oxidation (mainly OZONE) is a powerful technique to be used in treatment trains to make-up waters for re-use ( in situ ). For special tasks Advanced Oxidation Processes (AOP) might be required. (there is no one is the best AOP decision matrix) Some parameters are affected effectively some not! (COD, color, odor, germs) (hardness, conductivity) Decision criteria: - treatment requirements/goals - treatment efficiency (type of water, contaminants, ) - part of treatment train (harmony, synergies) - foot print - capital and operating cost 23

24 Waste water treatment technologies , ,0 Incineration / Evaporation Wet Air Oxidation Anaerob biological Treatm ent 1.000,0 AOP (Fenton) Aerob biological Treatm ent (activated sludge, MBR, Biofilter) COD [mg/l] 100,0 10,0 OZONE / AOP (OZONE + H2O2) AOP (UV/H 2 O 2 ) 1,0 0,1 electrolytic ozone generators / LBT UV Systems incl. MB (PHARMA) 0,1 1,0 10,0 100, , ,0 Flow [m³/h] 24

25 Recommend maximum levels of different parameters for industrial water re-use qualities Parameter (excerpt) High quality water textile industry Moderate quality water textile industry Low quality water textile industry Quality for sanitary paper paper industry Quality for cleaning water food industry Colour [mg/l Pt] COD [mg/l] ph Conductivity [µs/cm] Calcium [mg/l] Colony forming units [CFU/100ml] (other more) none visible AOP O O 3 3 AOP none visible O 3 none visible 20 O O O O Do you remember? AOP O 3 UV 25

26 Our Mission Source: watereducation.organisation ( 26

27 Thank you for your attention! UV Disinfection Ozone Oxidation Advanced Oxidation ANY QUESTIONS, COMMENTS? 27

The First Step in Effluent Treatment

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