Analisi di settore: i servizi a valore aggiunto

Indice: Definizione del settore - Analisi dei fattori di diffusione dei vas - Contesto concorrenziale - Analisi della domand

A global multinational survey of cefotaxime-resistant coliforms in urban wastewater treatment plants

The World Health Organization Global Action Plan recommends integrated surveillance programs as crucial strategies for monitoring antibiotic resistance. Although several national surveillance programs are in place for clinical and veterinary settings, no such schemes exist for monitoring antibiotic-resistant bacteria in the environment. In this transnational study, we developed, validated, and tested a low-cost surveillance and easy to implement approach to evaluate antibiotic resistance in wastewater treatment plants (WWTPs) by targeting cefotaxime-resistant (CTX-R) coliforms as indicators. The rationale for this approach was: i) coliform quantification methods are internationally accepted as indicators of fecal contamination in recreational waters and are therefore routinely applied in analytical labs; ii) CTX-R coliforms are clinically relevant, associated with extended-spectrum ?-lactamases (ESBLs), and are rare in pristine environments. We analyzed 57 WWTPs in 22 countries across Europe, Asia, Africa, Australia, and North America. CTX-R coliforms were ubiquitous in raw sewage and their relative abundance varied significantly (< 0.1% to 38.3%), being positively correlated (p < 0.001) with regional atmospheric temperatures. Although most WWTPs removed large proportions of CTX-R coliforms, loads over 103 colony-forming units per mL were occasionally observed in final effluents. We demonstrate that CTX-R coliform monitoring is a feasible and affordable approach to assess wastewater antibiotic resistance status

Reuse of treated municipal wastewater for irrigation in apulia region: The “IN.TE.R.R.A.” project

The use of non-conventional water resources including treated municipal wastewater has been increasing in the Mediterranean regions over the last decades to cope with water shortages and uneven rainfalls due to climate change. The aim of this paper is to present the first results from two years of experimental field activities carried out in two different demo-places in Southern Italy: the municipal wastewater treatment plants of Noci and Castellana Grotte (Apulia region). In these sites different vegetable crops (cucumber, lettuce, melon, endive in Noci and fennel, lettuce, fennel in Castellana Grotte) were grown in succession and irrigated in parallel with treated wastewater and conventional water pumped from wells, for comparing the effects of the different water sources on soil and vegetables. Reclaimed water quality was monitored for chemical and microbial parameters and compared with conventional water. At harvesting time, microbial indicators were measured on edible part of crops and in soil. Results show that the effluents produced by a full scale membrane bioreactor (MBR) treatment plant (Noci) comply with the stringent Italian standards for reuse in agriculture, and its microbiological quality is higher than the conventional well water. In Castellana Grotte the effluent quality of the two pilot plants was different according to the adopted technologies (MBR and tertiary cloth filtration), and sometimes depended on the quality of incoming wastewater. As for the agronomic results, in both sites crop yields were higher in the plots irrigated with treated wastewater, and the microbial indicators Escherichia coli and Salmonella were never found, at harvesting time, on edible parts of crops and in the soil

Role of Mesh Pore Size in Dynamic Membrane Bioreactors

Two identical bench-scale Self-Forming Dynamic Membrane BioReactors (SFD MBR) were set-up and operated for the treatment of real urban wastewater. The two bioreactors were equipped with meshes of different mesh pore size. Meshes having pore size values of 20 and 50 µm were tested under solid retention time (SRT) of 15 d, whereas meshes with 50 and 100 µm pore sizes were compared under SRT of 50 d. The results of long-term experiments showed very good overall performances by all systems at the steady state. High flux (in the range 61–71 L m−2 h−1) and very good effluent quality were obtained, with average suspended solids and chemical oxygen demanding values below 10 mg L−1 and 35 mg L−1, respectively. The mesh pore size did not have a major influence on the average cleaning frequency. However, the pore size affected the effluent quality in correspondence of two particular conditions: (i) immediately after mesh cleaning; and (ii) during operation under high suction pressures (mesh clogging not promptly removed through cleaning). Moreover, the mesh cleaning frequency was observed to be dependent on the SRT. In tests with 50 d SRT, the cleaning requirements were very low (one every five days), and this limited the influence of the mesh pore size on the effluent quality. In conclusion, in SFD MBR, the role of the mesh pore size on the effluent quality may be more or less relevant depending on the operating conditions that directly influence the Dynamic Membrane formation

Improving Recovery of Valuable Bio-Products from Sewage Sludge Using Innovative Membrane Technologies

Membrane bioreactor (MBR) technology has been employed in sewage sludge treatment within polyhydroxyalkanoate (PHA) production systems to tackle challenges like sustainable recovery of volatile fatty acids (VFA) and achieving high-quality effluent. Typically, MBRs utilize pressure-driven membranes, mainly ultrafiltration (UF) membranes. Despite its advantages, membrane fouling remains a significant hurdle, particularly when scaling up from laboratory-scale to pilot and full-scale plants. Living Membranes® (LM) offer a novel approach to self-forming dynamic membranes (SFDM), relying on the formation of a stable layer of sludge particles, organic compounds, and microorganisms between a cost-effective supporting materials. LM® reframes membrane fouling from a drawback to a key part of the treatment process. Being composed of organic materials, the encapsulated layer within LM® serves as both a carbon source and a nutrient trap, promoting microbial growth and ensuring high contaminant removal. This abstract presents insights from the application of pilot-scale ultrafiltration membrane bioreactor (UF-MBR) and Living Membrane® bioreactor (LMBR) for PHA production. The UF-MBR and LMBR technologies have been compared under both anaerobic conditions, aimed at VFA production via sewage sludge acidogenic fermentation, and aerobic conditions, mainly focused on the removal of contaminants. Preliminary results suggest that LM® offers a sustainable and efficient alternative to conventional UF membranes in sewage sludge treatment, potentially enhancing the recovery of valuable resources such as clean water, VFAs, and PHA

Metaproteomics Applied to Activated Sludge for Industrial Wastewater Treatment Revealed a Dominant Methylotrophic Metabolism of Hyphomicrobium zavarzinii

In biological wastewater treatments, microbial populations of the so-called activated sludge work together in the abatement of pollutants. In this work, the metabolic behavior of the biomass of a lab-scale plant treating industrial pharmaceutical wastewater was investigated through a metaproteomic approach. The complete treatment process included a membrane biological reactor (MBR) coupled with an advanced oxidation process (AOP) for partial breakdown of non-biodegradable molecules. Proteins from biomass samples collected pre- and post-AOP application were investigated by two-dimensional gel electrophoresis (2DE), mass spectrometry (MS), and finally identified by database search. Results showed that most proteins remained constant between pre- and post-AOP. Methanol dehydrogenase (MDH) belonging to Hyphomicrobium zavarzinii appeared as the most constantly expressed protein in the studied consortium. Other identified proteins belonging to Hyphomicrobium spp. revealed a predominant methylotrophic metabolism, and H. zavarzinii appeared as a key actor in the studied microbial community

Closing the water cycle in the agro-industrial sector by reusing treated wastewater for irrigation

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

Agro-industrial wastewater reuse for irrigation of a vegetable crop succession under Mediterranean conditions

In many countries of the Mediterranean region, characterized by frequent drought periods, agricultural production often occurs under water deficiency or conditions that cause the depletion of the existing water resources. In these areas, the reuse of reclaimed wastewater for crop irrigation could contribute to mitigate/decrease water shortage, support the agriculture sector and protect groundwater resources. In 1.5-year field experiments in Southern Italy (Apulia Region), the effects of irrigation with treated agro-industrial wastewater on soil properties, crops yield and qualitative traits of crop products, including their microbiological safety, were assessed. Groundwater (GW), secondary treated wastewater (SW) and tertiary treated wastewater (TW) from an innovative "on-demand" UV disinfection system were used to irrigate tomato and broccoli, cultivated in succession. The three irrigation water sources and the corresponding irrigated soils, plants and crop products were analyzed for the main physico-chemical characteristics, quali-quantitative parameters and fecal indicators. SW and TW showed higher values of the main physico-chemical parameters than GW. SW irrigated soil resulted in a significant increase of NH4-N, Na+, SAR, EC (below the threshold value beyond which a soil is defined as saline) during the first tomato crop cycle, and of pH during the broccoli growing season. Irrigation with treated wastewater did not significantly affect the marketable yield nor the qualitative traits of tomato and broccoli crops, except for the Na+ and NO3− content (below the threshold levels defined by the European guidelines for vegetables). High levels of E. coli (above the Italian limit for reuse), Fecal coliforms and Fecal enterococci (up to 104 CFU 100ml−1) were observed in the SW and, when chlorination was not done, in the TW. Nevertheless, E. coli was not isolated from any sample of soil, plant and crop product, probably due to its rapid die-off. Moreover, low concentrations of Fecal coliforms and Total heterotrophic count were found in plant and crop product. The drip irrigation system used, which avoided the close contact between water and plant, may have contributed to this. Under the conditions applied in this study, the reuse of treated agro-industrial wastewater for irrigation can be considered an effective way to cope with agricultural water shortage in the Mediterranean area