Bruno Domenjoud 1 , Sylvie Baig 2 , Santiago Esplugas 1 1 Department of Chemical Engineering, University of Barcelona, Spain. 2 Degrémont SA, France. Biotreated urban wastewater effluent treatment by oxidative and adsorption technologies Paris, May 25, 2011, IOA-IUVA World Congress
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Bruno Domenjoud 1, Sylvie Baig 2, Santiago Esplugas 1 1 Department of Chemical Engineering, University…
20 th IOA World Congress Paris, FRANCE, Why advanced treatment of wastewaters? Improvement of water quality Wastewater reuse: increase of water availability ADVANCED TREATMENT 3 Objective : Sustainable use of water Answer to water shortage Minimization of environmental and health risks New challenge : Emerging micropollutants removal
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Bruno Domenjoud1, Sylvie Baig2, Santiago Esplugas1
1Department of Chemical Engineering, University of Barcelona, Spain. 2Degrémont SA, France.
Biotreated urban wastewater effluent treatment by oxidative and adsorption technologies
Paris, May 25, 2011, IOA-IUVA World Congress
20th IOA World Congress Paris, FRANCE, 2011.
OUTLINE
Introduction Advanced treatment
Ozone and AOPs _ Fundamentals
GAC & PAC _ Fundamentals
Study Objectives
Experimental
O3 treatment
AC treatment
Process comparison
Conclusions2
20th IOA World Congress Paris, FRANCE, 2011.
Why advanced treatment of wastewaters? Improvement of water quality Wastewater reuse: increase of water availability
ADVANCED TREATMENT
3
Objective : Sustainable use of water Answer to water shortage Minimization of environmental and health risks
New challenge : Emerging micropollutants removal
Metallic or organic substances present in very low concentrations in the environment and that may have a toxic action at small concentration.
• Pharmaceuticals & Personal Care Products (PPCPs)– Cytostatic agents, immunosuppressive drugs– Human and veterinary antibiotics– Natural and synthetic hormones– Halogenated compounds such as iodinated Xray contrast media– Heavy-metal containing drugs and non-therapeutic medical agents
• Pesticides• Domestic and Industrial chemicals and their by-products
1,2-DichloroethaneTrichloromethaneTrichlorobenzenes HexachlorobenzeneHexachlorobutadieneHexachlorocyclohexanePentachlorophenolCadmium and cpds Mercury and cpds
Need to evaulate both the fate of the parent compounds as well as conjugates and bioactive by-products
20th IOA World Congress Paris, FRANCE, 2011.
Name E° (V)
Fluor 3,03
Hydroxyl radical 2,80
Ozone 2,07
Hydrogen peroxide 1,78
Potassium permanganate 1,68
Standards redox potentials (298 K, H2)
O3 AND AOPs _ Fundamental notionsMoxidized
O3
HO·
M
InitiatorsPromoters
M M’oxidized
Inhibition
Molecular O3 attack is selective : attack on high electronic density sites.HO· attack is much more unselective : few compounds resist to its action.
Initiators Promoters InhibitorsHydroxide ions
Hydrogen peroxideUV254 radiation
Heterogeneous catalystsOrganic matter
OzoneHydrogen peroxide
Organic Matter
Hydrogen peroxideCarbonates
Organic MatterTer-butanol
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20th IOA World Congress Paris, FRANCE, 2011.
GAC_ Fundamental notions
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breakthrough curve
time
Fixed bed operation
* Porous material
* Non destructive treatment
* Equilibrium “Langmuir equation”
break point
saturation point
active zone
20th IOA World Congress Paris, FRANCE, 2011.
OBJECTIVE OF THE STUDY
Specific objectives Organic micropollutant removal,
Evaluation of OM removal,
comparison between O3 and AC.
Contribute to a better knowledge on advanced technologies able to improve the quality of the water discharged from WWTPs, both considering the conventional parameters and emerging contaminants.
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20th IOA World Congress Paris, FRANCE, 2011.
EXPERIMENTAL _ Material & operating conditions
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CatalyticreductionO3 gas analyzer
O2
P
O3 generator
Air vent
Reactor
Pressure valve
O3 gas analyzer
PAir ventT
P
Trap of KITraps of
NaOH 2M
O3 liquidanalyzer
pH sensor
CatalyticreductionO3 gas analyzerO3 gas analyzer
O2
P
O3 generator
Air vent
Reactor
Pressure valve
O3 gas analyzer
PAir ventT
P
Trap of KITraps of
NaOH 2M
O3 liquidanalyzer
pH sensor
O2
P
O3 generator
Air vent
Reactor
Pressure valve
O3 gas analyzer
PAir ventT
P
T
P
T
P
Trap of KITraps of
NaOH 2M
O3 liquidanalyzer
pH sensor
20th IOA World Congress Paris, FRANCE, 2011.
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EXPERIMENTAL _ Material & operating conditions
20th IOA World Congress Paris, FRANCE, 2011.
EXPERIMENTAL _ Material & operating conditions
Ozonation general operating conditions and system parameters
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Ozone operating parameters In operation Inlet ozone gas phase concentration 10 - 40 Ng/m3 Inlet gas flow rate 60 - 100 NL/h Reaction temperature 20 ºC Sample volume 1 - 2 L Reaction pH Not adjusted Ozone system parameters
Reactor type Stirred tank reactor
Hydrodynamic behavior Completely mixed liquid Non-plug-flow for gas
Global mass transfer coefficient (Kla) 0.25 min-1
20th IOA World Congress Paris, FRANCE, 2011.
EXPERIMENTAL _ Material & operating conditions
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1 m3
Feedingtank
PINLET
OUTLET
1 m3
Feedingtank
PINLET
OUTLET
20th IOA World Congress Paris, FRANCE, 2011.
EXPERIMENTAL _ Material & operating conditions
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GAC adsorption general operating conditions and system parameters
GAC operational parameters In operationFlow type Down-flowFlow rate 80 L/hLoading rate 11 m/hGAC height 0.60 mEmpty Bed Contact Time 3.3 minPAC & GAC parameters
Filled symbols correspond to presence of SS and turbidity
good COD removal in all cases
Fastest COD removal en presence of SS due to the oxidation of the OM matter attached in the COD which is mainly hydrophobic and thus highly ozone reactive
Ozonation as well as GAC filtration technologies were shown to be effective in removing from urban secondary effluents most of the micropollutants regulated by the European Directives.
At ozone doses around 20 mg/L, only the HCH were shown to be ozone recalcitrant.
Ozonation achieved effective COD, TOC and UV254 removals.
At initial times of ozonation, the micropollutant oxidation proceeds simultaneously with the conversion of non biodegradable, aromatic and high molecular weight soluble substances into more biodegradable, less unsaturated and more fractioned molecules.
Oxidation of ammonia into nitrates, which increase the ozone needs, and dissolution of attached organic matter onto SS were also highlighted from the beginning of the ozone treatments.
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20th IOA World Congress Paris, FRANCE, 2011.
CONCLUSIONS AND RECOMMENDATIONS
Micropollutants adsorption onto GAC competes with the simultaneous adsorption of around 90 % of DOC.
High organic matter loaded would strongly limits the life time of the GAC. In consequence, effective pre-treatments are required upstream to make the GAC application suitable.
Depending on the chemical make-up of water pollution, the best technological solution can either be ozone oxidation or activated carbon adsorption. Cost comparison and Life Cycle Assessment study would draw the final selection of the best solution.
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Bruno Domenjoud1, Sylvie Baig2, Santiago Esplugas1
1Department of Chemical Engineering, University of Barcelona, Spain. 2Degrémont SA, France.
Biotreated urban wastewater effluent treatment by oxidative and adsorption technologies
Paris, May 25, 2011, IOA-IUVA World Congress
THANK YOU FOR YOUR ATTENTION !
The authors are grateful for the financial support from the Spanish Ministry of Industry (CDTI) within the framework of the Project CENIT: