Sustainable and effective utilization of olive mill wastes by applying physicochemical and biological processes

1. Sustainable and effective utilization
of olive mill wastes by applying
physicochemical and biological
processes
A.G. Vlyssides, professor
National Technical University of Athens
Chemical Engineering Department

2. World wide olive oil productionWorld wide olive oil production
Europe Africa Asia America
84%
8.5% 5.5%
2%

3. European Olive Oil ProductionEuropean Olive Oil Production
4 2 %
2 0 % 1 8 % 2 0 %

4. Greek situationGreek situation
 The olives and olive oil are inextricable part of GreekThe olives and olive oil are inextricable part of Greek
cultureculture
 In Greece there are 150.000.000 olive trees cultivatedIn Greece there are 150.000.000 olive trees cultivated
in 765.000 hectarein 765.000 hectare
 The yearly production of each tree rises up to 300 kgThe yearly production of each tree rises up to 300 kg
of olivesof olives
 The 1/3 of Greek farmers are working on cultivationThe 1/3 of Greek farmers are working on cultivation
of olivesof olives
 Olives and olive oil production in Greece rise upOlives and olive oil production in Greece rise up
1.750.000 tn and 400.000 tn respectively1.750.000 tn and 400.000 tn respectively

5. Situation in GreeceSituation in Greece
INSTALLATIONSINSTALLATIONS
 2,633 olive oil mills2,633 olive oil mills
 2,152 centrifugal systems (mostly 3-phases)2,152 centrifugal systems (mostly 3-phases)
 481 traditional (pressure squeezing)481 traditional (pressure squeezing)
 20 pomace processing plants20 pomace processing plants

6. OLIVE M ILL
-ΙΙΙ phases
10 t n ol ives0
134.4 tn wat er
21.4 t n oli ve oi l
49.6 t n poma ce
163.4 t nwa stewa ter
Tot al Solids 6 3.5( TS) g/ l
Tot al Suspende dSol ids ( TSS) 2.8 g/l
Tot al Volat ile Sol ids ( TVS) 5 7.37 g/l
As h g/l6.13
Tot al Organic C arbon TO C) 3 9.82 g/l(
Tot al Organic N it rogen g/l(ΤΚΝ ) 0.76
Tot al Phosphorus P O g/l( ) 0.5 32 5
pH 4.8
BO D 45.5 g/l5
CO D 92. 5 g/ l
olive oil 15 g/l
Conduct ivit y mmhos/ cm12
Tot al Phenolic Compounds TPCs) 10.65 g/l(
Potasium g/l(Κ Ο) 2.372
Dry mate r( DM ) 22.4 t n
Tota l Organic Carbon ( TO C) 9. 5 tn
kernel oil 1 t n

7. Proper characteristics for any
success treatment method
•To be technical effective
•To be integrated
•To be feasible
•To meet all Environmental limits

8. Marketable byproducts from
OMW
•Waste olive oil
•energy
•antioxidants
•Soil conditioner

9. DETOXIFICATION USING Fenton
REAGENTS BEFOR ANY BIOLOGICAL
TREATMENT
BasicBasic Fenton ReactionFenton Reaction
FeFe 22
+ H+ H22OO22 → Fe→ Fe 33
++ ΗΗOO
++ ΗΟΗΟ

10. Laboratory scale apparatus forLaboratory scale apparatus for
chemical oxidationchemical oxidation

11. Laboratory scale apparatus for
anaerobic digestion activity
determination

12. Optimum results for %TPC reduction
Maximum reduction TPC∞
= 92
%
Conditions:
Initial conc of H2
O2
: 3.037
g/l
Initial conc of Fe++
: 0.44
g/l
pH : 0.86
Temperature oC : 21.3
ο
C

13. Lab scale
UASB type
continuous
operation
anaerobic
digester for
methane
production
from oxidized
OMWW

14. Optimum results for Kmax
Maximum kmax
= 0.9 m3 of CH4/kg of
VSS/d
conditions:
Initial conc of H2
O2
: 3.2 g/l
Initial conc of Fe++
: 0.06 g/l
pH : 1.75
Τ : 15.7 ο
C

15. BIOREFINARY FOR OLIVE WASTES TOTALLY
UTILIZATION

16. Olive extraction from OMWW

17. Waste olive oil collection from OMWW

18. Pilot scale anaerobic digestion of OMWW

19. Biogas flare

20. Co-composting of solids with liquid
Olive Mill wastes

21. Characteristics of the soil conditioner
Parameter Value Limitations
Water Holding Capasity 248 g/L >150
Germination Intex 235 % >100
ratio C/N 17.9 >15
Organic mater 85.5% >60
Ash 12.2% <25
Organic Carbon 43.5% >30
Total Nitrogen 2.42% >1
Total phosphorous 1.78 g/kg >0.35
Cationic Echange Capasity (CEC) 62 meq/100g >50
Humic compounds 40.5 % >25
pH 7.8 6.5-8.5

22. Cultivation of grapesCultivation of grapes
Grape forGrape for
winewine
makingmaking
0% and0% and 10%10% mixture ofmixture of
with conventional soilwith conventional soil
Comparison after twoComparison after two
months cultivationmonths cultivation

23. Basic concept of sustainability of olive
cultivation

24. Annual mass balance of proposed integrated method for a
normal capacity Greek Olive Oil Mill

25. Conclusions
•The fenton oxidation is a key for effective
detoxification of OMWW
•After detoxification the anaerobic digestion could
be used for energy production
•The proper combination of detoxified and
anaerobicaly treated OMWW with the solid wastes
of Olive Mills in a co-composting process could give
an effective, feasible and integrated method for
OMWW green management

26. Thank you for your
attention