Treatment of two phase olive mill wastes and recovery of phenolic - - PowerPoint PPT Presentation

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Treatment of two phase olive mill wastes and recovery of phenolic - - PowerPoint PPT Presentation

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Treatment of two phase olive mill wastes and recovery of phenolic compounds Isolation of phenolic compounds from agroindustrial Byproducts V. Sygouni, A.G. Pantziaros, I. C. Iakovides, Ev. Sfetsa, P. Bogdou, E. Christoforou, C. A. Paraskeva

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Treatment of two‐phase olive mill wastes and recovery of phenolic compounds Isolation of phenolic compounds from agroindustrial Byproducts

  • V. Sygouni, A.G. Pantziaros,
  • I. C. Iakovides, Ev. Sfetsa, P. Bogdou,
  • E. Christoforou, C. A. Paraskeva

Department of Chemical Engineering, University of Patras & FORTH/ICE‐HT, Patras

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Recovery of phenolic compounds from: Olive Mill Wastewater + Olive Mill solid wastes‐ Olive leaves

  • Olive oil is a major agro‐industrial

product for all Mediterranean countries.

  • Unfortunately large quantities of
  • live mill wastewater (OMW) or

semi‐solid wastes are produced.

  • Its treatment is difficult and

expensive due to its high organic load and phenolic content.

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SLIDE 3

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OMW

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SLIDE 4

Treatment of Wastewaters and Solid Wastes‐ Isolation, Recovery and Purification of phenolic compounds from agricultural by–products (wastes)

  • Purification of olive mill wastewater phenols
  • Purification of olive leaf phenols
  • Purification of grape marc phenols
  • Purification of olive mill solid waste

phenols

  • Purification of coffee beans phenols

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SLIDE 5

Scope

  • Large amounts of agricultural byproducts are produced every year, some of

them rich in phenolic compounds.

  • Phenols are antioxidants with high‐added value and positive effects to the

human health.

  • Their separation for the production of cosmetic products, food supplements

etc., is of great interest.

  • For this purpose, a combination of solid‐liquid extraction, membrane filtration

and resin adsorption/desorption following by evaporation is proposed, for the production of phenolic concentrates.

  • The final products of the proposed process contain a large percentage of the

byproducts’ phenolic content, in a small fraction of the initial volume.

  • This technique, after modification, can be applied to a variety of phenol‐rich

byproducts, allowing the operation of phenol separation plant adjustable to local agricultural activities.

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Physicochemical Separation Techniques

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  • Solid‐liquid

extraction is the separation of target compounds from a solid matrix through the use

  • f the appropriate solvent.

Solvents: WATER‐ ETHANOL (accepted in food Industry) Important parameters:

  • Physical characteristics of the solid
  • Solvent
  • Temperature
  • Agitation

Type of extraction Solutes Free solids Solvent/product Diffusional extraction Soluble coffee Coffee beans water Sugar Sugar beets Water, to produce sugar Washing extraction Vegetable oils Oilseeds Hexane, hydrocarbons Flavors/Odors Flowers Ethanol Sugar Sugarcane Water Leaching Phosphoric acid Phosphate rock Sulfuric acid Gold Gold ore Sodium cyanide Chemical reaction Gelatin Bones and skins Aqueous solution (pH 3 to 4) Lignins Wood chips NaOH solution, sulfide/sulfite

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Physicochemical Separation Techniques

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  • Membrane filtration is a separation

technique that has many applications in chemical process industries. The most important attributes of a membrane material are:

  • Good permeability
  • High selectivity
  • Chemical stability
  • Resistance to fouling

http://www.watertechonline.com/sustainable‐membranes‐for‐wastewater‐applications/

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SLIDE 8

/43

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UF NF RO Resin 378 g/L Phenols 85 g/L Hydroxytyrosol

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Analytical Techniques

  • Total Phenols: Folin‐Ciocalteu reagent, gallic acid as standard, 720 nm.
  • Total Carbohydrates: L‐Tryptophane reagent, glucose as standard, 525 nm.
  • COD: 5220 D, Standard Methods.
  • TS: 2540 B, Standard Methods.
  • TSS: 2540 D, Standard Methods.
  • Simple Phenols: HPLC analysis, gradient elution, DAD detector.

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Olive Mill Wastewater Phenolic Compounds

  • Olive

mill wastewater (OMW) is a byproduct of the THREE‐phase extraction systems during the production of olive oil.

  • Olive mill semi‐solid (alperujo or pomace)

is a byproduct

  • f

the TWO‐phase extraction systems during the production

  • f olive oil.
  • Because of their partition coefficient,

most phenolic compounds of olive fruits end up in the wastewater produced and not in olive oil.

  • Oleuropein is the most common phenolic

compound of unripe olive fruits, but during maturity it is hydrolyzed to several simpler phenolic compounds like hydroxytyrosol and tyrosol.

10 Oleuropein Hydroxytyrosol Tyrosol

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Membrane Filtration of OMW (three phase decanter)

[g/L]

Initial OMW Sieving <0.125 mm UF Conc. UF Filtr. NF Conc. NF Filtr. RO Conc. RO Filtr. COD 107.23 99.08 257.73 51.10 61.03 32.72 65.48 6.47 TS 63.4 58.8 121.36 37.35 43.82 22.15 60.44 1.48 TSS 44 33 141 1.33 1.77 0.95 1.67 0.08 Ch 12.34 13.19 19.37 10.93 11.97 5.09 14.96 0.21 Ph 2.64 2.65 6.59 2.17 2.64 0.86 2.09 0.04

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Resin Adsorption/Desorption of OMW ROc

  • XAD4 and XAD16N yielded the best results. Even though the sample contained more carbohydrates than

phenols, resins adsorbed the dissolved phenols at a higher percentage.

  • When water was used as a desorption solvent, the small amount of carbohydrates that was adsorbed on the

resin was desorbed at a high percentage (60%). Ethanol, on the other hand, almost selectively removed the adsorbed phenols, while acetone removed both, carbohydrates and phenols.

  • Kinetic experiments allowed the optimization of flow rates and total volume of treated sample before the

resin surface was saturated.

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2 4 6 8 10 12 20 40 60 80 100 12 rv/h Ph 6 rv/h Ph 3 rv/h Ph 12 rv/h Ch 6 rv/h Ch 3 rv/h Ch

% Adsorption Filtrated Volume (rv) (a)

2 4 6 8 10 12 20 40 60 80 100

Carbohydrates Phenols

% Desorption with water Filtrated Volume (rv) (b)

1 2 3 4 5 6 20 40 60 80 100

Carbohydrates Phenols

% Desorption with ethanol Filtrated Volume (rv) (c)

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Final Concentrate of OMW Phenolic Compounds

Initial OMW RO concentrate Ethanolic resin effluent Distillation residue Volume, mL 16700 2000 1500 9 Phenols, g/L 2.64 ±0.04 2.09 ±0.02 2.36 ±0.01 377.50 ±8.34 Carbohydrates, g/L 12.34 ±0.49 14.96 ±0.03 3.84 ±0.01 293.92 ±1.28

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  • After

carbohydrates removal via the proposed resin process, the distillation under vacuum (‐0.95 bar, 55 °C) of the resin ethanolic effluent resulted to a final phenol concentration of 378 g/L in gallic acid equivalents in the distillation residue.

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Olive Leaf Phenolic Compounds

  • Olive leaves are a byproduct of
  • live fruit harvesting and initial

stages

  • f
  • live
  • il

extraction, during their separation from olive fruits.

  • Olive

leaf extracts have been proven to be rich in phenolic compounds, with the most prominent one being oleuropein, which, unlike in the olive fruit, it is not hydrolyzed to simpler phenols.

  • Oleuropein can be either bound to

a sugar molecule (Oleuropein glycoside) or be present in its free form (Oleuropein aglycon).

14 Oleuropein

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Extraction of Olive Leaf Phenols

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25 50 75 100 500 1000 1500 2000 2500 3000

Extracted compound (mg/L) Ethanol (% v/v) (a)

Phenols Carbohydrates

50 100 150 200 250 1000 2000 3000 4000 5000

Extratced compound (mg/L) Solids (g/L) (b)

Phenols Carbohydrates

30 60 90 120 150 180 210 2000 4000 6000 8000 10000

Extracted compound (mg/L) Time (min) (c)

Phenols Carbohydrates

Optimum extraction conditions Ethanol % Duration 120 min Solids/Solvent 250 g/L

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Membrane Filtration of Olive Leaf Extract

Initial UF conc. UF filtr. NF conc. NF filtr. Volume L 75 17 58 9 49 Total Ph mg/L 468 ±15 774 ±3 325 ±7 988 ±25 88 ±1 Total Ch mg/L 2801 ±30 3458 ±27 2140 ±179 5410 ±37 1249 ±24

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Final Concentration of Olive Leaf Phenols

Volume mL Total Phenols mg/L Total Carbohydrates mg/L NFc 1440 988 ±25 5410 ±37 Desorbed 720 1480 ±1 5260 ±35 Final concentrate 10 97890 ±1230 322333 ±3933

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  • 1.44 L of NF concentrate were treated with

the proposed resin process, leading to the production of 0.72 L of ethanolic effluent that was evaporated under vacuum (0.05 bar, 50 °C). The final concentrate had a volume of 10 mL .

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Olive oil semi‐solid wastes (pomace or alperujo)

Residual from the 2‐phase olive oil extraction process 60‐70% moisture Water Olive crump‐ pulp Solid Residual Olive oil OMW Olive crump ‐ pulp Olive oil Semi‐ Solid Residual (Pomace, solid 65% moisture) 3‐phase decanter 2‐phase decanter Crashing‐ washing of olive fruits Malaxation

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Extraction of phenols from olive oil semi‐solid wastes: A parametric study

20 40 60 80 100 100 200 300 400 500 600 700 800 900 1000 1100

C (mg / Lt) Solvent Conc. in Ethanol (%) TPC Carbohydrates 20 40 60 80 100 500 1000 1500 2000 2500 3000 3500 4000

Phenols, 50% ethanol Carbohydrates, 100% water Cabrohydrates, 50% ethanol Phenols, 100% water Phenolic ratio, 100% water Phenolic ratio, 50% ethanol Carbohydrates ratio, 100% water Carbohydrates ratio, 50% ethanol

Mass of solid waste (gr) Concentration (mg/L)

10 20 30 40 50

Ratio of phenols, carbohydrates mass per solid mass

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Extraction of phenols from olive oil semi‐solid wastes: A parametric study

5 10 15 20 25 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600

Concentration (mg/L) Addition of HCl (1N) (mL) Phenols (50% ethanol) Phenols (100% water) Carbohydrates (50% ethanol) Carbohydrates (100% water)

10 20 30 40 50 60 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400

Concentration (mg/L) Extraction temperature (

  • C)

Phenols (50% ethanol) Phenols (100% water) Carbohydrates (50% ethanol) Carbohydrates (100% water)

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Extraction of phenols from olive oil semi‐solid wastes: A parametric study

1 2 3 200 400 600 800 1000 1200 1400 1600 1800 2000 2200

Concentration (mg/L) Extraction repeatability Phenols (50% ethanol) Phenols (100% water) Carbohydrates (50% ethanol) Carbohydrates (100% water)

50 100 150 200 200 400 600 800 1000 1200 1400 1600 1800

Concentration (mg/L) Raw per minute (rpm) Phenols (50% ethanol) Phenols (100% water) Carbohydrates (50% ethanol) Carbohydrates (100% water)

Stirring rate, rpm

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Extraction of phenols from olive oil semi‐solid wastes: A parametric study

30 60 90 120 200 400 600 800 1000 1200 1400 1600 1800 2000 2200

Concentration (mg/L) Extraction time (min) Phenols (50% ethanol) Phenols (100% water) Carbohydrates (50% ethanol) Carbohydrates (100% water)

Maximum TPC concentration (mg/L) Maximum Carbohydrate concentration (mg/L) Solvent Type Conditions 100% H2O 50 % ethanol (95%), 50 % H2O 100% H2O 50 % ethanol (95%), 50 % H2O Temperature, 20oC 471.0 1020.3 2060.0 1373.3 Rate, 100 rpm 735.5 1008.3 1516.7 1603.3 Duration, 60 min 735.5 956.3 1516.7 1708.3 HCl, 0 mL 678.0 892.5 1436.0 1605.3 Mean Concentration 655.0 969.3 1632.3 1572.6

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Extraction of phenols from olive oil semi‐solid wastes: A pilot study

120 L Concentrate, 20 L

100 L

NF Concentrate 10 L 90 L RO Concentrate 11 L 79 L Permeate Permeate Permeate Extracted solution UF

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Extraction of phenols from olive oil semi‐solid wastes: A pilot study

UF‐ Feed‐ intermediate permeates‐ concentrates NF‐ Feed‐ intermediate permeates‐ concentrates RO Feed‐ intermediate permeates‐ concentrates

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Extraction of phenols from olive oil semi‐solid wastes: A pilot study

100 200 300 400 500 600 700 UF NF RO

c (mg/Lt) Samples

TPC

Raw Feed Pemeate Concentrate

TPC concentration at the raw, feed, permeate and concentrate streams at the UF, NF, RO membranes.

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Extraction of phenols from olive oil semi‐solid wastes: A pilot study

500 1000 1500 2000 2500 3000 3500 4000 4500 UF NF RO

c (mg/Lt) Samples

Carbohydrates

Raw Feed Pemeate Concentrate

Carbohydrates concentration at the raw, feed, permeate and concentrate streams at the UF, NF, RO membranes

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Extraction of phenols from olive oil semi‐solid wastes: A pilot study

5000 10000 15000 20000 25000 30000 35000 UF NF RO

c (mg/Lt) Samples

COD

Raw Feed Permeate Concentrate

COD at the raw, feed, permeate and concentrate streams at the UF, NF, RO membranes.

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Conclusions: Extraction of phenols from olive oil semi‐solid wastes

Optimal conditions Solvent: Water 50% ‐ ethanol 50 % Solid/solvent ratio: 20 gr/100 ml Temperature: 30‐ 40 0C Stirring rate: 100 rpm Duration: 1 hr Pilot study Fat and lipids and polyphenols are concentrated in UF retentate stream Simple phenolics are included in NF and RO concentrates Unfortunately carbohydrates are everywhere… Adsorption/desorption on specific resins / cooling crystallization/ melting crystallization/ freeze drying better purification of phenols… current work

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Acknowledgements

We acknowledge support of this work by the project “Innovative Actions in Environmental Research and Development (PErAn)” (MIS 5002358) which is implemented under the “Action for the Strategic Development on the Research and Technological Sector”, funded by the Operational Programme "Competitiveness, Entrepreneurship and Innovation" (NSRF 2014‐ 2020) and co‐financed by Greece and the European Union (European Regional Development Fund).

Thank you for your attention

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