Reuse of treated wastewater for crop irrigation can contribute to mitigate water stress, especially in Mediterranean countries. The use of reclaimed municipal wastewater for this purpose was demonstrated by numerous studies and full-scale installations. On the other hand, reuse of industrial effluents in irrigation is uncommon and the knowledge in this field is limited. This work aims at assessing the suitability of agro-industrial effluent reuse for irrigation. In the case study presented, a full-scale tertiary treatment based on membrane ultrafiltration and UV disinfection was tested at an agro-industrial site in Apulia (Italy). The wastewater treatment plant processed the stream produced at a vegetable canning factory, and the treated effluents were used for field scale irrigation tests. The variability of wastewater quality and its effects on treatment process performances and reclaimed water quality were investigated. An economic evaluation of the full scale tertiary treatment was also performed. The results showed that the adopted technologies effectively removed suspended solids and the faecal indicator Escherichia coli below the local standards for reuse in irrigation. Furthermore, the use of treated agro-industrial wastewater had no inhibitory effects on the growth of tomato and broccoli, neither resulted in any faecal contamination of crops. In general, the present study shows that reuse of treated wastewater for irrigation is a suitable practice to close the water cycle in the agro-industrial sector. This is very important in areas where the sustainability of agriculture and transformation activities depends on the water available for irrigation. This practice also avoids the discharge of pollutants into water bodies, reducing the environmental impacts of agro-industrial productions. (C) 2017 Elsevier Ltd. All rights reserved.

Treated wastewater reuse is increasing in semi-arid regions as a response to the effects of climate change and increased competition for natural water resources. Investigating the fate of bacterial indicators is relevant to assess their persistence in the environment and possible transfer to groundwater or to the food chain. A long-term field-scale experimental campaign and a soil column test were carried out to evaluate the fate of the fecal indicator Escherichia coli (E. coli) in a cultivated soil when contaminated water resources are used for irrigation. For field experiments, fecal contamination was simulated by dosing the indicator to the effluent of a membrane bioreactor, thus simulating a filtration system's failure, and irrigating a test field where grass was grown. The presence of E. coli on grass and topsoil samples was monitored under different scenarios. For evaluating the fate of the same indicator in the subsoil, a set of soil columns was installed next to the field, operated, and monitored for E. coli concentration over time and along depth. Real municipal wastewater was used in this case as source of fecal contamination. Results showed that short- and medium-term effects on topsoil were strongly dependent on the concentration of E. coli in the irrigation water. Limited persistence and no relevant accumulation of the indicator on the grass and in the topsoil were observed. Watering events performed after fecal contamination did not influence significantly the decay in the topsoil, which followed a log-linear model. The trend of the E. coli concentrations in the leaching of the soil columns followed a log-linear model as well, suggesting bacterial decay as the dominant mechanism affecting the underground indicator's concentration.

Escherichia coli (E. coli) is one of the most commonly adopted indicators for the determination of themicrobiological quality in water and treated wastewater. Two main types of methods are used for theenumeration of this faecal indicator: membrane filtration (MF) and enzyme substrate tests. For bothtypes, several substrates based on the ?-D-glucuronidase activity have been commercialized. Thespecificity of this enzyme for E. coli bacteria has generated considerable use of methods that identifythe ?-D-glucuronidase activity as a definite indication of the presence of E. coli, without any furtherconfirmation. This approach has been recently questioned for the application to wastewater. Thepresent study compares two methods belonging to the above-mentioned types for the enumerationof E. coli in wastewater: MF with Tryptone Bile X-glucuronide agar and the Colilert®-18 test.Confirmation tests showed low average percentages of false positives and false negatives for bothenumeration methods (between 4 and 11%). Moreover, the counting capabilities of these twomethods were compared for a set of 70 samples of wastewater having different origins and degreesof treatment. Statistical analysis showed that the Colilert®-18 test allowed on average for asignificantly higher recovery of E. coli.

The Membrane BioReactor (MBR) is a well-established filtration-based technology for wastewater treatment. Despite the high quality of the effluent produced, one of the main drawbacks of the MBR is membrane fouling. In this context, a possible evolution towards systems having potentially lower installation and operating costs is the Self Forming Dynamic Membrane BioReactor (SFD MBR). Key of this technology is the self-formation of a biological filtering layer on a support of inert material. In this work, a lab-scale aerobic SFD MBR equipped with a nylon mesh was operated at approximately 95 L m-2 h-1. Two mesh pore sizes (20 and 50 ?m) and three air scouring flow rates (150, 250, and 500 mLair min-1) were tested at steady state. Under all the tested conditions, the SFD MBR effectively treated real municipal wastewater. The quality of the produced effluent increased for lower mesh size and lower air scouring intensity.

Bacteria of activated sludge for wastewater treatment degrade and oxidize the polluting matter. They can also select and adapt to metabolize complex substrates. The knowledge of metabolic pathways for pollutant degradation becomes decisive to manage wastewater treatment plants. These pathways are strongly related to the bacterial enzymatic activity, that can be revealed through protein measurement. The protein set of a cell represents its functional picture in a given situation, and differently from the gene set it may change significantly according to environmental conditions. In biological wastewater treatment plants, metaproteomics can be applied to find the key enzymes or proteins of a process, and can reveal unexpected biochemical pathways. In every case it can show the metabolic dynamics of an entire consortium in different or targeted conditions.In order to evaluate the behavior of microbial consortia under well determined operating conditions, metaproteomics has been applied for the characterization of the biomass of a membrane bioreactor (MBR) treating an industrial wastewater (Salerno et al., 2016).The present work reports on the effects of changes in wastewater composition/supply on the biomass in terms of its functional response as measured through metaproteomics.

In the framework of the Euro-India project Water4Crops (call FP7 KBBE 2012-6, contract n. 311933) long term pilot scale tests were performed for evaluating the suitability of treated municipal wastewater effluents for irrigation. Two pilot plants were operated in order to evaluate the effectiveness of two different technologies and the quality of produced effluents with respect to national water quality standards for reuse in agriculture. Both the tested technologies were based on the coupling of biological processes and surface filtration, and each of the two pilots was made of: 1) a process based on surface filtration which treated a continuous flow; 2) a UV disinfection system treating only the effluent fraction used for irrigation, and operated on demand. The first plant was based on the technology IFAS-MBR (Integrated Fixed-film Activated Sludge - Membrane BioReactor), and treated raw sewage after preliminary screening. The second pilot was based on the technology FDG (Filtro a Dischi a Gravità, Gravity Disk Filter) and treated the secondary effluent. The effluents produced by the pilots were accumulated into storage tanks and submitted to on-demand UV disinfection (i.e. operated when irrigation was switched on). Results showed the effectiveness of both tested technologies in producing effluents suitable for reuse in agriculture and complying with the local standards.

The paper reports results of treated wastewater reuse field experiments carried out in Apulia (SouthernItaly). Fennel and lettuce were irrigated with four different water sources: three reclaimed wastewaterstreams, obtained by applying different treatment schemes to the same municipal wastewater, and aconventional source (well water). Differences between the three effluents were significant in terms ofsuspended solids and faecal indicators. Both lettuce and fennel yields were enhanced by the high contentof nutrients in the effluent of one of the treatment plants, which had been operated for partial nitrogenremoval. In particular, fennel productivity was enhanced by replacing chemical fertirrigation with thesupply of nutrients contained in the irrigation water.

Results of field experiments of wastewater reuse are presented. Two different crops (fennel and lettuce) were grown in succession on sandy loam soil and drip irrigated with three water sources: the effluent of the local full scale municipal wastewater treatment plant (WWTP), the effluent of a pilot scale non-conventional treatment technology, and a conventional source (well water). In order to evaluate the effects of higher ammonia and nitrate concentrations on crop yields and quality, the pilot plant was operated for partial nitrogen removal (mainly nitrification). Results showed that the pilot plant had better removal performance in terms of suspended solids and faecal indicators with respect to the full scale WWTP. As for the agronomic results, crop yields were significantly higher in plots irrigated with treated wastewater.

The Membrane BioReactor (MBR) has been widely applied for the treatment of both urban and industrial wastewater. A possible evolution towards systems having potentially lower installation and operating costs is the Self Forming Dynamic Membrane BioReactor (SFD MBR). The main characteristic of this technology is the self-formation of a biological filtering layer on a support (mesh) of inert material. The biological layer, also called "dynamic membrane", has a lower porosity than the mesh itself, so acting as the key player in the filtration processes.

Two lab-scale Self Forming Dynamic Membrane BioReactors (SFD-MBR), equipped with 50 µm nylon meshes were set up and operated for the treatment of real municipal wastewater. Plastic carriers were added in one of the two bioreactors to generate a combination of the Integrated Fixed-film Activated Sludge (IFAS) and the SFD-MBR technologies. Overall, the two systems performed very well, achieving excellent effluent quality under steady state conditions and showing good resilience to extreme organic loading conditions. Continuous air scouring and periodical mesh cleaning by jet rinsing with tap water were effective in maintaining stable and high productivity (membrane flux around 67 L m2 h-1) over a period of 140 days. The application of the IFAS process resulted in lower production of excess sludge and improved denitrification. On the other hand, under the tested conditions the combined IFAS-SFD-MBR showed a higher tendency to mesh clogging with respect to the SFD-MBR.

A lab-scale Membrane BioReactor (MBR) for the treatment of synthetic municipal wastewater was set-up. The functional response of the activated sludge of the plant to a change in the supply of the influent wastewater was investigated. After 60 days at the steady state, the volumetric loading rate (VLR) was suddenly reduced to 65% by reducing the influent flowrate and establishing stress conditions for the biomass.The VLR decrease resulted in a reduction of volatile suspended solids (VSS) in the mixed liquor and in a slight worsening of the chemical oxygen demand (COD) degradation with respect to the previous period. Respirometry results revealed that the autotrophic bacteria more promptly adapted to the organic load perturbation than the heterotrophic ones. More details were provided by the application of metaproteomics. Particularly, several species expressed the same molecular chaperone in different experimental stages, evidencing diverse organic supply stress thresholds by different bacteria. More, coherently with the respirometric approach, some proteins belonging to species based on nitrogen metabolism were found in all samples, confirming the good resistance of autotrophic genera such as Nitrosomonas or Nitrospira to the stress due to VLR decrease. Finally, the expression of 1-butanol dehydrogenase by Thauera butanivorans at the end of the experimentation indicates that some species developed different metabolic pathways such as the degradation of butane, which had not been detected in previous stages.

Il riutilizzo a fini irrigui delle acque reflue è in continuo aumento a causa della crescente scarsità di risorse idriche e della necessità di garantire la tutela dell'ambiente. In Italia, ed in particolare in Puglia, tale pratica non è ancora inserita stabilmente nelle politiche gestionali delle risorse idriche e, nonostante il Piano di Tutela delle Acque e gli attuali indirizzi politici favoriscono il riuso, la sua reale implementazione sconta difficoltà e ritardi dovuti a: 1) Requisiti qualitativi degli effluenti fortemente restrittivi imposti dalla legge 185/03, che si riflettono nella necessità di impianti complessi sul pianotecnologico e gestionale e in costi di trattamento elevati 2) Negativa percezione da parte di agricoltori, mass-media e presidi autorizzativi, relativa ai rischi associati all'impiego in agricoltura dei reflui depurati. Tra i 14 partecipanti al progetto In.Te.R.R.A. Intesis, operando trasversalmente su quasi tutti gli obiettivi realizzativi del progetto (OR1-OR2-OR3-OR4), ha progettato e sta realizzando un innovativo sistema di telecontrollo e telegestione degli impianti oggetto di sperimentazione, a partire dalla misura dei parametri qualitativi dell'acqua depurata da destinare all'uso irriguo. Il sistema di telecontrollo si basa su una infrastruttura hardware (server ridondato, storage, gateway VPN, rete) sicura e affidabile, realizzata presso il Data Center Intesis e sull'implementazione di diversi applicativi SCADA rispondenti al paradigma del Cloud Computing. In questo contesto, una compagine di soggetti pubblici e privati, coordinata dal Dipartimento di Scienze delle Produzioni Vegetali della Università degli Studi di Bari,ha presentato il progetto PON "Ricerca & Competititività" 2007-2013 In.Te.R.R.A. per lo sviluppo e la sperimentazione di "INnovazioni TEcnologiche e di processo per il Riutilizzo irriguo delle acque Reflue urbane e Agro-industriali ai fini della gestione sostenibile delle risorse idriche". Il portale realizzato da Intesis nell'ambito del progetto "In.Te.R.R.A." è stato utilizzato dai partner dello stesso progetto per il controllo degli impianti sperimentali e per l'acquisizione di dati in tempo reale. L'IRSA-CNR ha cercato di sfruttare tutte le potenzialità del portale sin dalla sua prima pubblicazione (ottobre 2012), partecipando, come utente critico, al miglioramento dello stesso.

In order to mitigate water stress in the Mediterranean area, treated municipal wastewater is among the most readily available alternative water resources. Apulia (Southern Italy) is one of the Mediterranean regions most heavily affected by water shortage, although its economy is strongly based on irrigated agriculture. Nevertheless in Apulia only 1% of treated wastewater potentially available for reuse in agriculture is presently used, mainly because of regulatory constraints and public acceptance. Within the EU funded project Water4Crops different types of treatment schemes are applied at the pilot scale to treat municipal wastewater and polish secondary effluents for reuse in irrigation. In the present study, results from test field experiments carried out at Castellana Grotte (Apulia) are presented. Three different crops (processing tomato, fennel and lettuce) were grown in succession on sandy loam soil and drip irrigated with three water sources: the effluent of the local full scale municipal wastewater treatment plant (WWTP), the effluent of a pilot scale non-conventional treatment technology, and a conventional source (well water). The full scale WWTP is composed of a conventional activated sludge process followed by sand filtration, coagulation-flocculation and chlorination (conventional tertiary treatment). The pilot plant is an integrated process scheme called IFAS/MBR (Integrated Fixed-film Activated Sludge/Membrane BioReactor) followed by UV disinfection. In order to evaluate the effects of higher ammonia and nitrate concentrations on crop yields and quality, the IFAS/MBR pilot plant was operated for partial nitrogen removal (mainly nitrification). Reclaimed water quality was monitored in terms of chemical and microbiological parameters and compared with conventional well water. Microbiological indicators were also measured at harvesting time in soil and on the edible parts of crops. Chemical analyses of soil and crops were also performed in order to assess possible variations across the different water sources adopted. Results showed that the pilot plant had better removal performance in terms of suspended solids and faecal indicators with respect to the full scale WWTP. The effluent of the full scale WWTP compliedwith the Italian standards for reuse in agriculture, except for chlorine and E. Coli, while the effluent of the pilot plant exceeded the limit values only in terms of ammonia and nitrate. As for the agronomic results, crop yields where significantly higher in plots irrigated with treated wastewater. In particular the higher content of nitrates in the pilot plants effluent strongly enhanced the lettuce yield. Microbiological indicators E.Coli and Salmonella were never detected in soil and edible parts at harvesting time.

Nel corso dello lavoro sperimentale effettuato, un bioreattore a membrana in scala pilota è stato realizzato ed operato con un processo di aerazione continua per il trattamento di un'acqua reflua urbana sintetica. L'effluente in uscita dal sistema è stato utilizzato per irrigare una parcella coltivata con prato ed è stata monitorata sia la crescita di questo che la qualità dell'effluente utilizzato. La parcella sperimentale è stata confrontata con una seconda parcella di riferimento irrigata con una fonte convenzionale (acqua di pozzo).L'idea principale del lavoro è di utilizzare a fini irrigui l'effluente di un MBR operato con l'obiettivo di ottenere la rimozione della sostanza organica e la nitrificazione dell'ammoniaca e del nitrito per ottimizzare la produzione di nitrato nell'effluente, che rappresenta un elemento essenziale per la crescita delle piante. Questa attività è stata svolta nell'ambito del progetto PRIN (bando 2008) denominato "Trattamenti innovativi per il riutilizzo a scopo irriguo delle acque reflue".