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Treated wastewater reuse in Puglia (Southern Italy):Demo and full scale activities
Alfieri POLLICE
BackgroundFactors affecting water stress in Med countries:
1.Increasing coastal urbanization.2.Seasonal water stress (warmer season) due to simultaneous increase of:
• Tourism fluxes,• Agricultural requirements,• Uneven precipitations and higher temperatures (climate change),• Over-exploitation of natural resources.
% of available water yearly abstracted
Possible tools to tackle water stress include:• Water demand management
(water loss contrast, irrigation techniques, economic measures, training, etc.)• Water supply increase
(seawater desalination, wastewater reuse, rainwater harvesting etc.)
Yearly rainfall in the Med Basin 2
Reuse of treated wastewater in agriculture
Opportunities Continuous water supply; Safeguard of primary sources; Nutrients supply.
Risks Microbiological safety; Chronic effects on soils; Eutrophication of storage basins.
Are costs sustainable ? Are technologies adequate ? Are limits and regulations representative of local situations ? How stakeholders and final users can be involved ?
Questions
Background
3
Perceived complexity of TWWR (cross-sector issues concerning water, food, health and the environment) and need for some technical knowledge
Regulations not always suited to local contexts
Inadequate tariff policy (heavily subsidized conventional water resources) and limited financial capacity
Competition for conventional water resources and need to define priorities (need for planning supply and demand)
Risks of soil salinization, crops contamination, and pollution of water resources (need of monitoring proceduresand some analytical skills)
Public perceptioncould be highly negative, causing rejection of projects
Obstacles to TWWR in Med countriesBackground
4
Strongly ruralRuralModerately ruralUrbanStrongly urban
Rainfall (1960-2010)
Puglia: 600-650 mm/year136 m3/capita per yearabsence of permanent rivers/natural lakes
Cultivated 79%
Irrigated 19%
Other 21%
Land use
Puglia – Available water and land use
Wastewater treatment and effluent reuse
0
200
400
600
800
1000
1200
Agricultural Civil IndustrialDestination
Con
sum
ptio
n (M
m3 /y
)
External Resources (border regions) Regional Resources (groundwater)
Total Regional Water demand
1500 Mm3/y
Municipal wastewater potentially available for reuse in irrigation: • Total estimate 150 Mm3/year• Tertiary wastewater treatment plants currently available 90 Mm3/year
Further advantages:• Nutrient recovery• Continuous supply
Water demand in PugliaSavings on primary resources = 10%
Regional Water Plan of Puglia (2007)
Opportunities of reuse for irrigation in Puglia
Conventional wastewater treatment (activated sludge)
Primarysettling
Pre-treatment Activatedsludge
Secondarysettling
Rawwaste
Tertiarytreatments
Standards for discharge
Standards for reuseB) polishing
Water body(river/lake/sea)
A) upgrade or
Treated wastewater reuse in irrigation
Primarysettling
Pre-treatment
Activatedsludge
Rawwastewater
A) Upgrade of activated sludge process (Membrane Bioreactors – MBR)ultra FILTR
DISINF Effluent to irrigation
IRSA demo-scale activities: Surface filtration combined to biological processes
From treatment for effluent disposalto water production for irrigation
B) Polishing: Tertiary surface filtration processesDISINF
micro FILTR
ultra FILTRDISINFSe
cond
ary
efflu
ent
Efflu
ent
to ir
rigat
ion
• Study of processes based on low pressure surface filtration for the production of water suitable for irrigation, study of microbiological quality and nutrientconservation.
• IRSA’s main research projects on treated effluent reuse:2000-2002: POM - national,2002-2006: PON – Aquatec - national,2005-2008: FP6 – Reclaim Water – EU,2006-2009: FP6 – Aquastress – EU,2010-2012: PRIN - national,2011-2015: PON – Interra (also agro-industrial ww) - national,2012-2016: FP7 KBBE – Water4Crops - EU-India,2013-2016: FP7 Inno-Demo – Demoware - EU,2016-2018: Water JPI/ERANET Waterworks 2014 – MeProWaRe – EU.
IRSA activities on surface filtration for wastewater treatment and reuse
Case study 1 (Aquatec 2000/2006):Tertiary membrane filtration
Cerignola WWTP
50,000 P.E.
Test field2000 m2
Tertiary treatment (membrane) and
storage tanks
Pilot plant of 700 L/h
Membrane flux: 30 L/m2/hMembrane surface: 23,5 m2
Cerignola
Case study 1 (Aquatec 2000/2006):The pilot plant and the test field
2000 m2=16 parcels 5x24 mdrip irrigation (Soil Water Deficit 35%)
Storage tanks 30 m3
MBR
TEST FIELD irrigated with treated wastewater (MBR effluent) + E. coli
Persistence of E. coliin surface soil and on grass ?
E. coli (and NO3) transfer through soil layers… possibly to groundwater ?
SOIL COLUMNS irrigated with partially treated real wastewater
Case study 2 (PRIN 2010-2012):Fate of E. Coli in irrigation with treated wastewater
Pilot scale MBRQ=15 L/hSRT=25 days; HRT=6 hProd./Relax=3h/6min
Vergine et al. (2015) - Fate of the fecalindicator Escherichia coli in irrigationwith partially treated wastewater. WaterResearch, 85, 66-73.
WWTPoutlet
WWTPinfluent
2) GDF + UVSecondary effluent
1) IFAS-MBR + UVPre-screened wastewater
SETTLERS
ACTIVATED SLUDGE
SETTLERS
FILTR.CHLOR.COAG.-
FLOC.-SED.
Case study 3 (Water4Crops 2011/2016):IFAS-MBR and GDF for direct irrigation
Test field (3000 m2)Horticulture irrigated with treated effluents (including the WWTP outlet) and control (well water)
15mm
15mm
UV disinfection
0.5-1.0 m3/h Storage tanks (30m3)
UV on demand
(*) Integrated Fixed film-Activated Sludge Membrane BioReactor
Test field
Case study 3 (Water4Crops 2011/2016):IFAS-MBR(*) with on-demand UV disinfection
Open channel UV-C disinfection
n. 6 lamps(Hg vapor)
25m3/h UV on demand
Test fieldIN = secondary
effluent
Case study 3 (Water4Crops 2011/2016):GDF(*) with on-demand UV disinfection
(*) Gravity Disk Filter
GDF – Cloth filtration(polyester), pores of 20µm
Case study 4 (Demoware 2011/2016):Treated agro-industrial wastewater for irrigation
discharge
+ tertiarytreatment
irrigation
WWTPWW
Agro-ind. WW:• 12-15 mc/h• Quality + flowrate
fluctuations
Tertiary treatment:• Sand filtration• Membrane filtration• UV on-demand
Case study 5 (Fasano full scale plant):Tertiary treatment for water distribution to farmers
Initial configuration•Pre-chlorination (NaClO)•Clariflocculation (AlCl3)•Post-disinfection (O3/UV)
New configuration1. Simultaneous dosage of:•AlCl3 (clariflocculation)•NaClO or PAA (disinfection)•PAC (adsorption)2. Lamellar packs settlers
Irrigation network:•1500 hectares•30 km piping•48 farms
WWTP: 25.000 PE
Storage lake: 40.000 m3
Cost of tertiary treated water: 0,16-0,25 €/m3 (on the water bill)Cost of distribution: depends on volume, distance, irrigationtype (contracts with farmers).
Acquavivadelle Fonti
150-200 m3/h800 m3
900
m3well
Water types:•Well water;•Treated wastewater;•Blend of the two.
17
Stakeholders: Farmers association, water utility, municipality.
Case study 6 (Meproware 2016/2018):Blending ww effluents with well water for irrigation
Next steps forward
• Demo/full-scale technology testing aimed at stakeholdersinvolvement and communication (also to the general public).
• Specific work on the INTERFACE between water production (WWTP) and water utilization (farmers).
• Developement of decision support systems (DSS) and mangement tools, identification of best management modelsfor local needs (private vs participated vs public, etc.).
• Dissemination of results towards policy makers.
THANKS FOR YOUR ATTENTION