Approach in the agroindustry water management:

a case study

Agenzia nazionale per le nuove tecnologie,l’energia e lo sviluppo economico sostenibile

Roberto Farinaroberto.farina@enea.it

Unità Tecnica Modelli, Metodi e Tecnologie per le Valutazioni AmbientaliLaboratorio Protezione della Risorsa Idrica, via Martiri di Monte Sole, 4 - 40129 Bologna

Water use in industry • Cleaning- washing• Transport

– Material– Heat

• Dilution• Cooking• Product component

Water use in industry:quality

• Legislation refer only at:– Discharge in the environment– Safety for the workers and products– Quality, just for the agroindustry

Water use in industry:quantity

• Legislation refer only at:– IPPC directive– Local legislation– Local agreements with public authorities

Industry considered

• Fruit industry with production of– Clear juice fruit– Concentrates juice fruits– Flavors– Desiccated fruit– Fourth range fruit

Industry considered

• Use of water– Washing of fruit– Cleaning of machinery– Steam production

• Quantity of water discharged 480mc/d

Wastewater cycle

Reflui

Effluente

Aria

Canale di scarico reflui

Riciclo Fanghi

Fanghi a digestione

BIOGAS

PRODUZIONE EQUALIZZATORE FILTRO ANAEROBICO

VASCHE A FANGHI ATTIVISEDIMENTATORE

AREA DI RINATURALIZZAZIONE

Acque di pioggia Toilette

Characteristics of the wastewater tested

Refluo 1 Refluo 2 Refluo liquido 3 Bucce refluo 3

COD totale mg/l 4970 3330 3550

COD disciolto mg/l 4020 2180 2230

Solidi Totali g/kg 4.5 3.45 3.93 250

Solidi Volatili g/kg 3.03 2.07 2.71 246

Soldi sospesi tot g/l 2.45 0.61 1.9

Solidi sospesi vol g/l 1.126 0.5 1.3

Azoto ammoniacale mg/l

13 25.6 14

Azoto totale mg/l 14 67.4 57 1600 g/kg

pH 4.2 4.8 4.6 3.7

Test BMP effluent 2

Produzione specifica refluo 2

00,05

0,10,15

0,20,25

0,30,35

0,4

L C

H4/

g C

OD

Specific Production : 0.34 l CH4/g COD

Test BMP peelings

Specific Production: 0.43 l CH4/g SV

Produzione specifica refluo 3

00,050,1

0,150,2

0,250,3

0,350,4

0,450,5

14/1

2/20

09

16/1

2/20

09

18/1

2/20

09

20/1

2/20

09

22/1

2/20

09

24/1

2/20

09

26/1

2/20

09

28/1

2/20

09

30/1

2/20

09

01/0

1/20

10

03/0

1/20

10

05/0

1/20

10

L CH

4 / g

SV

Lgas/gSV

17 days 23 days

Biomethanation test

Continues flow UASB reactor

SEPARATOR GLS

FEEDING POINT

RICIRCOLO

Effluent 2 after UASB treatment

PARAMETRO VALORE PARAMETRO

COD disciolto 240 mg/l

Solidi Totali 1,025 g/kg

Solidi Volatili 0,127 g/kg

Solidi Sospesi Totali 0,09 mg/l

Solidi Sospesi Volatili 0,05 mg/l

Azoto Ammoniacale 15,7 mg/l

Azoto Totale 16,8 mg/l

pH 7,3

Performances:Organic load removal : 92.8 %Total solids removal: 70 %Biogas quality: 89 % CH4

PARAMETRO VALORE PARAMETRO

COD 270 mg/l

Solidi Totali 2.1 g/kg

Solidi Volatili 1.3 g/kg

Solidi sospesi totali 0.09 g/l

Solidi sospesi volatili 0.07 g/l

Azoto ammoniacale 12.8 mg/l

Azoto totale 35 mg/l

Performances:Organic load removal: 96 %Total solids removal: 49 %Biogas quality: 77 %

Effluent 3 after UASB treatment feed batch

PARAMETRO VALORE PARAMETRO

COD 110 mg/l

Solidi Totali 1.89 g/kg

Solidi Volatili 0.84 g/kg

Solidi Sospesi Totali 0.09 g/l

Solidi sospesi Volatili 0.09 g/l

Azoto ammoniacale 26 mg/l

Azoto totale 30 mg/l

pH 7

Performances: Organic load removal: 98 %Total solids removal: 45 %Biogas Quality: 85 % CH4

Effluent 3 after mesophilic UASB treatment feed batch

New waste water cycle

Concentrated wastewaters

Effluente

Canale di scarico reflui

Fanghi a digestione

BIOGAS

PRODUZIONE EQUALIZZATORE FILTRO ANAEROBICO

AREA DI RINATURALIZZAZIONE

Acque di pioggia Toilette

alimentazione

influente

reazione

sedimentazionescarico

scaricofango

scaricoeffluente

attesa

Diluted wastewaters

peeling

Why and SBR reactor

SBR (Sequencing Batch Reactors) activated sludge discontinuous biological treatment systems.Possibility to have in one basin all the different phases of a biological process (organic matter and nitrogen removal, sludge sedimentation) in different moments, not in different basins.

alimentazione

influente

reazione

sedimentazionescarico

scaricofango

scaricoeffluente

attesa

The 4 different phases of an SBR are:FeedingReactionSedimentationDischargeall the different phases can variate according with the characteristics of the wastewater quality and quantity and according with the effluent characteristics.

Management flexibility according with the possibility to

change the duration of the different phases; Simplification of the plant engineering; Higher flexibility to organic and hidraulic loading changes; Improving the sedimentability characteristics of the sludge

according with the selection of the biomass; Possibility/necessity of a complete automation of the

process Possibility to reduce the aeration cost

Adavantages of the SBR technology

Conclusions

Not always it is necessary to apply new technologies to improve the wastewater treatment in an industry.

Segregation of effluents allow to reduce process volumes and provide better wastewater characteristics for each specific treatment.

Segregation of effluents allow the reuse of wastewaters even without treatment