Treated wastewater reuse in Puglia (Southern Italy): Demo and full scale activities Alfieri POLLICE alfieri.pollice@cnr.it
Background Factors 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. 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.) 2 Yearly rainfall in the Med Basin % of available water yearly abstracted
Background 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. Questions Are costs sustainable? Are technologies adequate? Are limits and regulations representative of local situations? How stakeholders and final users can be involved? 3
Background Obstacles to TWWR in Med countries 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 Competition for conventional water resources and need to define priorities (need for planning supply and demand) Inadequate tariff policy (heavily subsidized conventional water resources) and limited financial capacity Risks of soil salinization, crops contamination, and pollution of water resources (need of monitoring procedures and some analytical skills) Public perception could be highly negative, causing rejection of projects 4
Puglia Available water and land use Rainfall (1960-2010) Strongly rural Rural Moderately rural Urban Strongly urban Other 21% Land use Puglia: 600-650 mm/year 136 m 3 /capita per year absence of permanent rivers/natural lakes Irrigated 19% Cultivated 79%
Wastewater treatment and effluent reuse Opportunities of reuse for irrigation in Puglia Consumption (Mm 3 /y) 1200 1000 800 600 400 200 0 Water demand in Puglia External Resources (border regions) Regional Resources (groundwater) Total Regional Water demand 1500 Mm 3 /y Agricultural Civil Industrial Savings on primary resources = 10% Further advantages: Nutrient recovery Continuous supply Destination Municipal wastewater potentially available for reuse in irrigation: Total estimate 150 Mm 3 /year Tertiary wastewater treatment plants currently available 90 Mm 3 /year Regional Water Plan of Puglia (2007)
From treatment for effluent disposal to water production for irrigation Conventional wastewater treatment (activated sludge) Raw waste Pretreatment Treated wastewater reuse in irrigation Primary settling Activated sludge Secondary settling Tertiary treatments Water body (river/lake/sea) Standards for discharge A) upgrade or B) polishing Standards for reuse IRSA demo-scale activities: Surface filtration combined to biological processes A) Upgrade of activated sludge process (Membrane Bioreactors MBR) Raw wastewater Pretreatment Primary settling Activated sludge ultra FILTR DISINF Effluent to irrigation B) Polishing: Tertiary surface filtration processes Secondary effluent micro FILTR ultra FILTR DISINF DISINF Effluent to irrigation
IRSA activities on surface filtration for wastewater treatment and reuse Study of processes based on low pressure surface filtration for the production of water suitable for irrigation, study of microbiological quality and nutrient conservation. 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.
Case study 1 (Aquatec 2000/2006): Tertiary membrane filtration Test field 2000 m 2 Pilot plant of 700 L/h Membrane flux: 30 L/m 2 /h Membrane surface: 23,5 m 2 Tertiary treatment (membrane) and storage tanks Cerignola WWTP 50,000 P.E. Cerignola
Case study 1 (Aquatec 2000/2006): The pilot plant and the test field 2000 m 2 =16 parcels 5x24 m drip irrigation (Soil Water Deficit 35%) Storage tanks 30 m 3
Case study 2 (PRIN 2010-2012): Fate of E. Coli in irrigation with treated wastewater TEST FIELD irrigated with treated wastewater (MBR effluent) + E. coli SOIL COLUMNS irrigated with partially treated real wastewater Persistence of E. coli in surface soil and on grass? MBR Pilot scale MBR Q=15 L/h SRT=25 days; HRT=6 h Prod./Relax=3h/6min E. coli (and NO 3 ) transfer through soil layers possibly to groundwater? Vergine et al. (2015) - Fate of the fecal indicator Escherichia coli in irrigation with partially treated wastewater. Water Research, 85, 66-73.
Case study 3 (Water4Crops 2011/2016): IFAS-MBR and GDF for direct irrigation CHLOR. SETTLERS WWTP outlet FILTR. ACTIVATED SLUDGE COAG.- FLOC.-SED. SETTLERS WWTP influent 1) IFAS-MBR + UV Pre-screened wastewater 2) GDF + UV Secondary effluent Test field (3000 m 2 ) Horticulture irrigated with treated effluents (including the WWTP outlet) and control (well water)
Case study 3 (Water4Crops 2011/2016): IFAS-MBR (*) with on-demand UV disinfection 0.5-1.0 m 3 /h Storage tanks (30m 3 ) UV on demand 15mm 15mm Test field UV disinfection (*) Integrated Fixed film-activated Sludge Membrane BioReactor
Case study 3 (Water4Crops 2011/2016): GDF (*) with on-demand UV disinfection GDF Cloth filtration (polyester), pores of 20µm 25m 3 /h UV on demand IN = secondary effluent Test field n. 6 lamps (Hg vapor) (*) Gravity Disk Filter Open channel UV-C disinfection
Case study 4 (Demoware 2011/2016): Treated agro-industrial wastewater for irrigation irrigation Agro-ind. WW: 12-15 mc/h WW WWTP + tertiary treatment Quality + flowrate fluctuations Tertiary treatment: Sand filtration discharge 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 (AlCl 3 ) Post-disinfection (O 3 /UV) WWTP: 25.000 PE Irrigation network: 1500 hectares 30 km piping 48 farms Storage lake: 40.000 m 3 New configuration 1. Simultaneous dosage of: AlCl 3 (clariflocculation) NaClO or PAA (disinfection) PAC (adsorption) 2. Lamellar packs settlers Cost of tertiary treated water: 0,16-0,25 /m3 (on the water bill) Cost of distribution: depends on volume, distance, irrigation type (contracts with farmers).
Case study 6 (Meproware 2016/2018): Blending ww effluents with well water for irrigation Acquaviva delle Fonti Stakeholders: Farmers association, water utility, municipality. 800 m 3 150-200 m 3 /h well 900 m 3 Water types: Well water; Treated wastewater; Blend of the two. 17
Next steps forward Demo/full-scale technology testing aimed at stakeholders involvement 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 models for local needs (private vs participated vs public, etc.). Dissemination of results towards policy makers.
THANKS FOR YOUR ATTENTION alfieri.pollice@cnr.it