School of Environmental Engineering Technical University of Crete - - PowerPoint PPT Presentation

▶
school of environmental engineering technical university
SMART_READER_LITE
LIVE PREVIEW

School of Environmental Engineering Technical University of Crete - - PowerPoint PPT Presentation

Jan 28, 2024 485 likes •768 views

School of Environmental Engineering Technical University of Crete Edible olives processing The olives usually are collected at different stages of maturity and then processed to eliminate the characteristic bitter taste, due to the glucoside

slide-1
SLIDE 1
slide-2
SLIDE 2

School of Environmental Engineering Technical University of Crete

slide-3
SLIDE 3

Edible olives processing

School of Environmental Engineering Technical University of Crete

The olives usually are collected at different stages of maturity and then processed to eliminate the characteristic bitter taste, due to the glucoside oleuropein The table olives debittering process can be accomplished using two ways:

  • The “Chemical method” (Spanish/Californian style)
  • The “Natural method” (Greek style)

Greek style Spanish/Californian style

slide-4
SLIDE 4

Edible olives dibittering processes

School of Environmental Engineering Technical University of Crete

Chemical method (Spanish/Californian style) Treatment with NaOH solution, followed by fermentation in 5-6% brine Natural method (Greek style) Direct fermentation in 6-10% brine

NaOH

5 ton wastewater per ton of olives 0.8 ton wastewater per ton of olives

slide-5
SLIDE 5

Edible-olives fermentation

School of Environmental Engineering Technical University of Crete

Fermentation takes place in industrial reactors from fiberglass Fermentation takes place in plastic barrels

Chemical method Natural method

β-glucosidase ~90% of polyphenols is removed ~60% of polyphenols is removed

slide-6
SLIDE 6

Edible-olives processing wastewater

School of Environmental Engineering Technical University of Crete

slide-7
SLIDE 7

Edible olives processing wastewater

School of Environmental Engineering Technical University of Crete

Chemical method Natural method Lye produced after the treatment of olives with NaOH

slide-8
SLIDE 8

Characteristics of edible-olives processing wastewater

School of Environmental Engineering Technical University of Crete

  • High COD (7,500-25,000 mg/L)
  • High BOD5 (5,000-15,000mg/L)
  • Relatively high TSS concentration (800-2,000mg/L)
  • Moderate concentration of nitrogen (50-200 mg/L)
  • Relatively high concentration of phosphate (50-200mg/L)
  • High oil & grease content
  • High concentration of polyphenolic compounds
  • High conductivity
  • High salinity
  • Extreme pH (very high or very low)
  • Dark color

Wastewater characteristics depend on the process used

slide-9
SLIDE 9

Common treatment practices

School of Environmental Engineering Technical University of Crete

Aerobic biological Coagulation/flocculation Evaporation Anaerobic biological Oxidatio- Photooxidation Edible-olives wastewater Co-processing in municipal wastewater facilities often results in plant destabilization Often the edible-olives wastewater is discharged illegally into natural receivers Combinations of the above have also been tried

slide-10
SLIDE 10

Geopolymers

School of Environmental Engineering Technical University of Crete

A relatively complex reaction (polycondensation) between aluminosilicate- containing powders (e.g. fly ashes and/or reactive clays) with alkali metal silicates or hydroxides

Geopolymers (active clay sediments):

Three-dimensionally cross-linking alumininosilicates amorphous inorganic materials Consist of various inorganic repeating units, such as: silico-oxide (-Si-O-Si-O-) silico-aluminate (-Si-O-Al-O-) ferro-silico-aluminate (-Fe-O-Si-O-Al-O-) alumino-phosphate (-Al-O-P-O-)

Geopolymerisation:

Portland cement Geopolymer

slide-11
SLIDE 11

School of Environmental Engineering Technical University of Crete

  • Irreversible adsorption of a large spectra of wastes (organic, inorganic,

heavy metals)

  • Can be structured so to be adsorption-selective (eg: for heavy metals,
  • rganic wastes, radioactive wastes, etc

Use of geopolymers for wastewater treatment:

  • Binding materials
  • Ceramics
  • Arts and demonization
  • Restoration of archeological findings
  • Fire resistance materials
  • Adsorption/encapsulation of wastes

Uses of geopolymers

Uses of geopolymers:

slide-12
SLIDE 12

Geopolymer

School of Environmental Engineering Technical University of Crete

slide-13
SLIDE 13

Edible-olives processing wastewater treatment using the active clays sentiments (geopolymers)

School of Environmental Engineering Technical University of Crete

  • Flow equalization
  • Removal of coarse solids
  • pH adjustment
  • Chemical oxidation
  • Coagulation
  • Adsorption on geopolymer
  • Removal of sediment (clarification)
  • Filtration of supernatant
  • Polishing (photo-oxidadtion using nanocatalyst)
  • Disinfection

Process depends on wastewater characteristics

slide-14
SLIDE 14

Process diagram for edible-olives wastewater treatment

School of Environmental Engineering Technical University of Crete

Inlet Stabilized sludge R Geochemical reactor Clarifier Dewatering

Air

Geopolymer Chemical

  • xidation

Rotary drum Equalization tank

Air

Polishing tank H+

  • r

OH- pH adjustment Oxidation agent Filter Outlet Sludge Cl Coagulant Filtrate Filtrate Light Nano- catalyst H2O2

slide-15
SLIDE 15

Application

School of Environmental Engineering Technical University of Crete

  • Edible olives production

facility in Chalkiliki, Greece

  • Capacity: 10,000 ton olives

per year

  • Method: partly “chemical”,

partly “natural” process

slide-16
SLIDE 16

Types of edible-olives wastewater

School of Environmental Engineering Technical University of Crete

Equalization tank

School of Environmental Engineering Technical University of Crete

slide-17
SLIDE 17

School of Environmental Engineering Technical University of Crete

Reactor tanks

School of Environmental Engineering Technical University of Crete

slide-18
SLIDE 18

School of Environmental Engineering Technical University of Crete

Geopolymer addition tank

School of Environmental Engineering Technical University of Crete

slide-19
SLIDE 19

School of Environmental Engineering Technical University of Crete

Geopolymer inside the feeding silo

School of Environmental Engineering Technical University of Crete

slide-20
SLIDE 20

School of Environmental Engineering Technical University of Crete

Filter press and sedimentation tank

School of Environmental Engineering Technical University of Crete

slide-21
SLIDE 21

IN 7500 8300 9450 8760 2000 4000 6000 8000 10000

1 2 3 4

mg/l

OUT 18 2 1 9 5 10 15 20

1 2 3 4

mg/l

IN 900 1120 960 1080 200 400 600 800 1000 1200

1 2 3 4 mg/l

OUT 84 25 12 93 10 20 30 40 50 60 70 80 90 100

1 2 3 4

mg/l

TSS BOD

Treatment efficiency

slide-22
SLIDE 22

OUT 16 11 9 7

2 4 6 8 10 12 14 16 18

1 2 3 4

mg/l

IN 40 55 98 62

20 40 60 80 100 120

1 2 3 4

mg/l

OUT 1,5 0,5 0,1 0,3

0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8

1 2 3 4

mg/l

IN 85 69 102 135

20 40 60 80 100 120 140 160

1 2 3 4

mg/l

P TN

Treatment efficiency

slide-23
SLIDE 23

IN 650 630 695 980 200 400 600 800 1000 1200

1 2 3 4

NTU

OUT

2 0,5 1 1,5 2 2,5

1 2 3 4

NTU

Turbidity

Treatment efficiency

School of Environmental Engineering Technical University of Crete

Sludge leaching tests:

Concentrations of dissolved organic carbon are by far below the limits set by the legislation

slide-24
SLIDE 24

BOD 8760 7008 85 9 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 Inlet Chemical

  • xidation

Geochemical processing Chemical refining

mg/l

TN 135 135 7 7 20 40 60 80 100 120 140 160 Inlet Chemical

  • xidation

Geochemical processing Chemical refining

mg/l

P 62 62 10 20 30 40 50 60 70 Inlet Chemical

  • xidation

Geochemical processing Chemical refining

mg/l

Treatment efficiency stage by stage

School of Environmental Engineering Technical University of Crete

slide-25
SLIDE 25

Cost

  • The capital cost of a full geochemical wastewater

treatment plant with capacity of 15,000 m3/yr has been calculated between 250,000 €

  • The operation cost (including chemicals, geopolymer

and energy) has been calculated between 2.7-3.2 €/m3

  • Cost is competitive, taking into account the process

stability and the fact that discharge limits can be achieved

School of Environmental Engineering Technical University of Crete

slide-26
SLIDE 26

Conclusions

  • The use of active clay sediments process can achieve

complete treatment of edible olives processing wastewater

  • The process comprises by a series of sub-processes,

including pH adjustment, chemical oxidation, coagulation, geopolymer reaction, clarification, filtration, photo-oxidation

  • The capital and operational costs for small-medium olive

processing faculty has been calculated as 250,000 €, 2.7-3.3 €/m3, respectively

  • Wastewater treatment process should take into account

recent technological achievements and the needs of the modern society

School of Environmental Engineering Technical University of Crete

slide-27
SLIDE 27

Thank you for your attention

School of Environmental Engineering Technical University of Crete

petros.gikas@enveng.tuc.gr

School of Environmental Engineering Technical University of Crete