Search Results (151)

Microplastics (MPs) in water treatment plants (WTPs) represent a critical environmental concern, particularly when treated effluent is reused for agricultural irrigation. This study investigates the occurrence, removal efficiency, and characterization of MPs in tertiary-treated wastewater destined for agricultural reuse in water-scarce regions. Additionally, the study examines the influence of sample volume on extrapolated MP concentrations. Despite advanced treatment processes including ultrafiltration achieving removal efficiencies of 89%, substantial quantities of MPs remain in final effluents at concentrations ranging from 89 to 399 MPs/m³ (equivalent to 0.1–0.4 MPs/L) with a mass load of 2 µg/L at the outlet. Morphological analysis revealed a shift from fragment-dominated influent (~50%) to film-dominated effluent (~51%), with blue particles being most prevalent. Size distribution analysis showed distinct peaks: 50–100 µm for fragments, 100–250 µm for films, and 250–500 µm for fibres. Polytetrafluoroethylene (PTFE) emerged as the dominant polymer across all morphotypes. Finally, converting particle counts to mass loads indicated an average decrease from ~11 µg/L at the inlet to ~2 µg/L at the outlet, underscoring that number- and mass-based metrics provide complementary information for risk assessment. Full article

The reuse of treated wastewater for agricultural irrigation is increasingly considered a strategic response to water scarcity and climate change, particularly in Mediterranean regions. This study examines the local feasibility and social acceptance of water reuse within the framework of Regulation (EU) 2020/741, focusing on its implementation in Italy. The research combines policy analysis, technical assessment of effluent quality from the GIDA wastewater treatment plant (Prato, Tuscany), GIS-based spatial evaluation, and a mixed-method survey of local agri-food producers. Results show substantial compliance with EU minimum quality requirements, alongside additional constraints arising from national regulatory thresholds. Survey findings reveal cautious but tangible openness among farmers toward reclaimed water use, particularly in response to increasing climate-related pressures. The case of Prato is further analysed within the Prato Circular City and local food policy frameworks, highlighting the role of participatory governance and multi-actor engagement in supporting reuse initiatives. The study contributes empirical evidence on the interaction between EU regulation, national implementation measures, and local socio-institutional conditions shaping peri-urban water reuse systems. Furthermore, it serves as a preliminary framework for future economic feasibility studies and the subsequent regulatory and permitting phases required to operationalize this practice. Full article

The secondary effluent from printing and dyeing wastewater contains recalcitrant organic pollutants, such as azo dye derivatives. Their persistence in aquatic environments not only creates ecological risks but also hampers the high-value reuse of reclaimed water. This study investigated the influence of typical binary anions on the degradation performance of low-concentration azo dye wastewater using a Ti/RuO₂-IrO₂ anode electrochemical oxidation system. The results demonstrated that maximum COD removal efficiency could reach 50.22%, and the controlling factors synergistically regulated the contribution and competition between Reactive Chlorine Species and free radicals. This led to a characteristic “rapid rise–decline–slow rebound” phenomenon in the COD removal rate, with the inflection points co-influenced by the current density, conductivity, and binary anion ratio of the electrochemical process. Furthermore, it alters the degradation pathway of the azo dye to “azo bond cleavage → demethylation/desulfonation → dehydroxylation/deamination oxidation → benzene ring opening”. Within a fixed duration of 60 min, the Response Surface Methodology model identified the optimal COD degradation conditions as follows: current density of 19.72 mA/cm², Cl⁻/SO₄²⁻ ratio of 5.40, and conductivity of 8.30 mS/cm. This research elucidates the differences between the electrochemical oxidation degradation pathway of low-concentration azo dye wastewater under the regulation of typical binary anions and the conventional pathway. It also reveals the regulatory effects of current density, conductivity, and binary anion ratio on the degradation patterns. Full article

The beneficial reuse of reclaimed water is a legislative objective of the State of Florida and a critical element in the optimization of water management in areas facing scarcity of freshwater. Aquifer storage and recovery (ASR) of reclaimed allows for the balancing of variations in seasonal and longer-term supply and demand. Destin Water Users, Inc. (DWU), which serves a barrier island community in the Florida panhandle, implemented a groundbreaking ASR system that stores reclaimed water in a shallow sand-and-gravel aquifer. Institutional controls were used to provide additional assurance that public health is protected, and natural contamination attenuation processes are taken advantage of to address arsenic leaching into stored water and disinfection byproducts (trihalomethanes) removal. The DWU ASR system eliminated the need for more expensive and environmentally impactful options for the disposal of excess of reclaimed water and increases the reliability of the reuse system, having the benefit of reserving higher-quality fresh groundwater resources for potable use. Full article

Growing water scarcity across the European Union (EU) increases the need for improved water-use efficiency in water-intensive sectors such as recreational facilities. This study evaluates the feasibility of integrating alternative water sources—including rainwater, graywater, and filter backwash water—into swimming pool operations through a comparative analysis of EU legislation and selected national regulatory frameworks. The study is based on a structured desk review of scientific literature, legal documents, and technical standards published between 2010 and 2025, complemented by a qualitative SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis. Previous studies indicate that public swimming pool facilities may consume approximately 20–50 m³ of water per day, highlighting the potential benefits of alternative water supply strategies. However, regulatory fragmentation and the absence of harmonized EU-level quality standards for recreational water reuse remain the main barriers to wider implementation. While Regulation (EU) 2020/741 establishes minimum requirements for reclaimed water reuse in agricultural irrigation, no dedicated framework exists for swimming pool facilities. Among the analyzed options, rainwater harvesting and graywater reuse appear to be the most feasible solutions. Clearer regulatory guidance and risk-management procedures could support the safe adoption of alternative water sources and contribute to improving water-use efficiency in the recreational sector. Full article

Water reuse may pose risks to the environment and human health due to pathogens or chemical pollutants (hazards) in reclaimed water arising from treatment or distribution system failures (hazardous events). In this context, the European Regulation EU 2020/741 requires the development of a Risk Management Plan (RMP) from the source to the irrigated fields. This study proposes a methodology to assess and manage the risk to guarantee a reliable treatment able to produce an effluent adequate for reuse. It combines Failure Mode and Effect Analysis (FMEA) with a Risk Priority Number (RPN) approach. FMEA identifies failure modes for the treatment components (hazardous events), their consequences for the system, and the hazards for environment and human health. The RPN measures the failure risk by the product of the likelihood of occurrence L, magnitude of effects M and ease of detection D for each failure. Due to a lack of data, L, M and D are estimated through scores. Failure risks are classified as low, medium, high and very high. The last step is the revision of existing corrective actions or the adoption of new ones to reduce the risk of critical failures (highest RPN). This methodology is applied to a large wastewater treatment plant (Class A technology, according to EU 2020/741). Out of the 303 failure modes identified for the 86 components, 12 are the most critical (very high risk) and the suggested additional corrective actions reduce L and/or D and thus M. This methodology supports an RMP for similar or more complex treatment plants. Full article

Growing wastewater volumes and intensifying water scarcity are driving the need for affordable, sustainable solutions that enable safe urban water reuse and strengthen climate resilience. Policy frameworks such as SDG6 and EU water reuse requirements highlight that reclaimed water must meet strict environmental and public health standards. In contrast, conventional biological treatment cannot fully remove many emerging contaminants, underscoring the need for advanced treatment approaches that consistently deliver high-quality reclaimed water. In this context, this review examines the role of membrane technologies (MF, UF, NF, RO, FO) and membrane bioreactors (MBRs) in providing safe water in urban environments and in enhancing urban climate resilience, including decentralized systems and advanced reclamation needs. It also discusses the contribution of membrane-based solutions to sustainable cooling systems and heat-stress mitigation, as well as the integration of membrane technologies into green infrastructure and nature-based solutions for climate adaptation. Technical and economic performance is shaped by fouling, cleaning requirements, and energy use, making life-cycle and operational optimization critical for long-term sustainability. Case studies and EU-funded initiatives demonstrate that, with appropriate governance and design, membrane-based approaches can enable reliable reclaimed water supply, enhance water security, and contribute to circular urban water management. The analysis was based on peer-reviewed open-access publications, which may introduce a degree of selection bias. Full article

Using reclaimed water for irrigation is an effective strategy in semi-arid regions facing water scarcity. However, this water may contain pharmaceutical residues, posing potential environmental and health risks. To ensure sustainable reuse, it is essential to study how these substances accumulate in soil and transfer to crops. The aim of this research was to develop and optimise a rapid Ultrasound-Assisted Extraction method combined with Ultra-High-Performance Liquid Chromatography–tandem Mass Spectrometry for quantifying 23 pharmaceuticals in non-cultivated soil. Following optimisation, 18 compounds were successfully extracted using a MeOH:H₂O ratio of 75:25. The detection and quantification limits were found to range from 0.52 to 0.5 ng·g⁻¹ and 1.75 to 35 ng·g⁻¹, respectively. The matrix effects and recoveries varied by compounds’ type and concentration, but most results were acceptable. The evidence suggested that some drugs underwent microbial degradation. Soil irrigated with reclaimed water via subsurface drip since 2012 occasionally contained four pharmaceuticals (caffeine, carbamazepine, tamoxifen, and venlafaxine) at low concentrations, while others were absent. This indicates the capacity of soil to act as a barrier, and highlights the importance of proper water management. The study concludes that reclaimed water reuse is safe if supported by efficient treatment and management, offering a promising approach for long-term sustainability in water-scarce regions. Full article

The use of reclaimed water is crucial to prevent pollution from wastewater discharges and mitigate the water deficit faced by irrigation districts or other non-potable water users. Therefore, the zero-discharge strategy represents a significant challenge for coastal cities affected by marine pollution from effluents. In regions such as the Mediterranean arc, agricultural areas located near these cities are increasingly exposed to reduced water allocations or rising irrigation demands due to the impacts of climate change. To address this dual challenge, a circular system is proposed through the implementation of hybrid treatment technologies that enable zero wastewater discharge into the sea. This approach would contribute up to 30 hm³ of reclaimed water annually for irrigation, covering approximately 27,000 hectares of cropland in the province of Alicante. The proposed system integrates advanced techniques, such as reverse osmosis, to ensure irrigation water quality, while also considering partial blending strategies to optimize resource use. Additionally, constructed wetlands are incorporated to regulate and treat the reject streams produced by these processes, minimizing their environmental impact. This combined strategy enhances water reuse efficiency, strengthens agricultural resilience, and provides a sustainable model for managing water resources in coastal Mediterranean regions. Full article

Water resources’ carrying capacity (WRCC) is crucial for sustainable development, linking natural resources with social and economic systems. Although Anji County in China has relatively abundant water, uneven distribution, strong seasonality, and rising demand from industrialization and population growth have kept the system close to overload. Using a comprehensive evaluation and optimization framework, this study assessed WRCC from 2015 to 2023. Results show the county has long operated near its threshold, with water shortages projected to reach 23% by 2025, though pressures may ease by 2030. Key constraints include high industrial water use, limited reuse of treated wastewater, and low per capita availability. Model simulations suggest that optimized allocation of surface water, groundwater, and reclaimed water could improve carrying capacity by up to 30%. These findings highlight the need for industrial upgrading, water-saving measures, and expanded wastewater reuse, providing practical guidance for resource management in Anji County and a useful reference for other regions facing similar challenges. Full article

Reusing treated wastewater (TWW) in agriculture may reduce water use pressure. While TWW is often used for soil irrigation, its application in hydroponics remains limited. In these systems, TWW can serve as a source of nutrients for plants while also being further reclaimed. We evaluated two TWWs of different origin and composition for hydroponic rocket cultivation. Each TWW was tested in its native form (TWW1 and TWW2) and after dilution and supplementation with mineral salts (TWW1_DH and TWW2_DH), using a Hoagland nutrient solution as a control. Yield and qualitative aspects of the product, including health risk factors (nitrates and heavy metals), were assessed. Rocket grown in TWW1 reached the harvesting stage, but with a significant yield reduction compared to the control (−40%). In TWW2, plants reached only the cotyledon stage and were not harvested. Two harvests were obtained in TWW1_DH and TWW2_DH, with yields comparable to the control or even significantly higher (+25%) in the first harvest in TWW1_DH. No health concerns were detected, with values of Health Risk Index < 1 for all the heavy metals and nitrate levels (~3000 mg kg⁻¹ FW) well below EU limits. The study highlights the potential of TWW for the hydroponic cultivation of rocket, but also highlights the need to tailor its use based on composition. Full article

The reclaimed water sector is poised for significant growth driven by urbanization, technological advancements, and increasing demand for alternative water sources, with an emphasis on improving treatment capacities and promoting water reuse for various applications. This study examines the challenges and market potential of reclaimed water as a strategic solution to address water scarcity in Europe, assessing the regulatory framework, associated risks, and reuse potential. A multi-phase analysis was conducted, including a review of the European directives, an analysis of water scarcity, an evaluation of wastewater reuse potential, identification of risks and technological challenges, and segmentation of the reclaimed water market across various European regions. Results highlight the significant underutilization of treated wastewater in Europe; only about 3% of urban wastewater is reused, equal to 1 billion m³/year (2.4% of effluent, <0.5% of freshwater withdrawals). Wastewater is often regarded as a pollutant rather than a resource; yet, advances in recycling and treatment technologies have increased safety and efficiency, making it a practical solution to water scarcity while strengthening climate resilience. At the strategic level, the study concludes that Europe holds strong potential for water recovery and a substantial opportunity to tackle water scarcity through innovative recovery solutions, thereby contributing to sustainability, fostering a circular economy, and promoting planetary health. Full article

Climate change is projected to significantly reduce water availability, particularly in arid and semi-arid regions, which makes hydrological planning essential given the increasing competition for water resources. Inefficient consumption patterns exacerbate water depletion and highlight the importance of water quality management. Promoting sustainable practices, reducing consumption, and enhancing water recycling contribute to a more resilient approach. The aim of thIS study is to evaluate the reuse of reclaimed water in the Vega Alta region, which accounts for almost 15% of the total water mix (about 99 hm³/year) as it reuses 92.52% of the treated wastewater, most of which is pumped to irrigation areas targeted for consolidation, also creating new landscapes. These figures place the Region of Murcia as the leading autonomous community in Spain for water reuse, although challenges remain regarding water volumes and the associated costs, investment, and maintenance. Full article

Water scarcity in Jordan is intensifying, creating an urgent need for innovative approaches to maximize the use of nonconventional water resources, such as greywater treatment and reuse. This study presents a detailed analysis of the suitability of nature-based solutions (NbSs) for greywater treatment, with a focus on the application of horizontal flow constructed wetlands (HFCWs). Two systems were implemented to treat greywater generated from mosques located in Az-Zarqa Governorate, a dry region in Jordan. Following several months of operation, monitoring, and evaluation, the systems demonstrated high removal efficiencies: turbidity (>87%), total suspended solids (TSS) (>96%), chemical oxygen demand (COD) (>91%), and five-day biological oxygen demand (BOD₅) (>85%). The eight-square-meter HFCW units successfully produced one cubic meter of treated greywater per day, meeting Jordanian standards for reclaimed greywater (JS 1776:2013) for use in irrigating food crops, including those consumed raw. The system achieved a 70% reduction in water consumption compared to the same period in the year prior to its implementation. These results demonstrate the potential of constructed wetlands (CWs) as effective, low-cost, and sustainable NbSs for decentralized greywater treatment and reuse in water-scarce regions. Full article

This study evaluates the potential use of reclaimed sand from municipal wastewater treatment plants (WWTP), categorized as waste under code 19 08 02, as a full substitute for natural sand in cement mortars. The sand was subjected to alkaline pretreatment using sodium hydroxide (NaOH) at concentrations of 0.5%, 1% and 2% to reduce organic impurities and improve surface cleanliness. All mortar mixes were prepared using CEM I 42.5 R as the binder, maintaining a constant water-to-cement ratio of 0.5. Mechanical testing revealed that mortars produced with 100% WWTP-derived sand, pretreated with 0.5% NaOH, achieved a mean compressive strength of 51.9 MPa and flexural strength of 5.63 MPa after 28 days, nearly equivalent to reference mortars with standardized construction sand (52.7 MPa and 6.64 MPa, respectively). In contrast, untreated WWTP sand resulted in a significant performance reduction, with compressive strength averaging 30.0 MPa and flexural strength ranging from 2.55 to 2.93 MPa. The results demonstrate that low-alkaline pretreatment—particularly with 0.5% NaOH—allows for the effective reuse of WWTP waste sand (code 19 08 02) in cement mortars based on CEM I 42.5 R, achieving performance comparable to conventional materials. Although higher concentrations, such as 2% NaOH, are commonly recommended or required by standards for the removal of organic matter from fine aggregates, the results suggest that lower concentrations (e.g., 0.5%) may offer a better balance between cleaning effectiveness and mechanical performance. Nevertheless, 2% NaOH remains the obligatory reference level in some standard testing protocols for fine aggregate purification. Full article