Search Results (27)

With increasing global challenges related to water scarcity and phosphorus depletion, the recovery and reuse of wastewater-derived nutrients offer a sustainable path forward. This study evaluates the dual role of lanthanides (Ce³⁺ and La³⁺) in recovering phosphorus from municipal wastewater and supporting corn (Zea mays) cultivation through lanthanide phosphate (Ln-P) and lanthanide-reclaimed wastewater (LRWW, wastewater spiked with lanthanide). High-purity precipitates of CePO₄ (98%) and LaPO₄ (92%) were successfully obtained without pH adjustment, as confirmed by X-ray photoelectron spectroscopy (XPS) and energy-dispersive spectroscopy (EDS). Germination assays revealed that lanthanides, even at concentrations up to 2000 mg/L, did not significantly alter germination rates compared to traditional coagulants, though root and shoot development declined above this threshold—likely due to reduced hydrogen peroxide (H₂O₂) production and elevated total dissolved solids (TDSs), which induced physiological drought. Greenhouse experiments using desert-like soil amended with Ln-P and irrigated with LRWW showed no statistically significant differences in corn growth parameters—including plant height, stem diameter, leaf number, leaf area, and biomass—when compared to control treatments. Photosynthetic performance, including stomatal conductance, quantum efficiency, and chlorophyll content, remained unaffected by lanthanide application. Metal uptake analysis indicated that lanthanides did not inhibit phosphorus absorption and even enhanced the uptake of calcium and magnesium. Minimal lanthanide accumulation was detected in plant tissues, with most retained in the root zone, highlighting their limited mobility. These findings suggest that lanthanides can be safely and effectively used for phosphorus recovery and agricultural reuse, contributing to sustainable nutrient cycling and aligning with the United Nations’ Sustainable Development Goals of zero hunger and sustainable cities. Full article

Water scarcity in semiarid regions represents a critical challenge for sustainable agriculture, reducing the availability of forage and affecting livestock systems. The reuse of treated wastewater offers an environmentally friendly alternative to meet water and nutrient needs, supporting the principles of the circular economy. Sweet sorghum, with its remarkable tolerance to abiotic stress, represents a resilient crop option. Evaluating its agronomic and industrial responses to different depths of irrigation using reclaimed water is essential for improving resource-efficient agricultural practices in water-limited environments. This study evaluated the effects of different irrigation regimes with treated wastewater on the growth, productivity, and water use efficiency of sweet sorghum grown in a semiarid region of Brazil. The experiment was conducted in a randomized complete block design, with five irrigation regimes ranging from 50% to 150% of crop evapotranspiration (ETc) and four replications. Irrigation was carried out with treated wastewater using a drip irrigation system. Growth parameters, fresh biomass, water use efficiency, and soluble solids content (°Brix) were analyzed in two consecutive harvests (main and ratoon crop). Deficit irrigation regimes (50% and 75% of ETc) resulted in higher water use efficiency and higher °Brix, whereas regimes above 100% of ETc reduced water use efficiency and biomass productivity. The ratoon crop showed greater sensitivity to water management, with significant productivity responses under irrigation around 100% of ETc. The first harvest was more productive in terms of fresh biomass and plant growth. Reclaimed water is a sustainable and efficient strategy for cultivating sweet sorghum in semiarid regions. Deficit irrigation regimes can be technically viable for maximizing water use efficiency and production quality, while proper irrigation management is crucial to avoiding losses associated with excessive water application. Full article

Water scarcity has become an increasingly critical global issue, affecting various sectors, including industrial, domestic, and particularly agriculture. Agriculture, as the largest consumer of water due to its substantial water requirements for food production, faces significant challenges, which are expected to intensify with the growth of the global population. As a result, many countries have begun to explore innovative solutions to address this pressing problem, one of which is the reuse of wastewater for irrigation purposes. This approach has gained particular attention in viticulture, where water consumption is high, and the need for sustainable practices is paramount. This paper delves into the issue of water scarcity, focusing specifically on the winemaking sector. It reviews several studies investigating the potential of wastewater reuse for irrigating vineyards, highlighting both the promising benefits and the challenges associated with this practice. The findings suggest that using treated wastewater for irrigation in viticulture offers a viable solution to mitigate water shortages, particularly in regions facing severe droughts or limited freshwater resources. However, the successful implementation of this approach requires careful monitoring and management of several factors, including soil quality, plant health, fruit development, and the final wine product. Ensuring the safety and quality of the wine, as well as safeguarding consumer health, necessitates rigorous oversight to prevent any negative impacts from the use of reclaimed water. Full article

In this work, a sustainable approach to reclaiming high-value anatase/rutile TiO₂ nanoparticles from deactivated or used selective catalytic reduction (SCR) catalysts is demonstrated using a composite flux (NaOH/Na₂CO₃) through an efficient sintering and subsequent leaching methodology. This method directly addresses the urgent need for circular economy strategies in industrial waste management. Sintering experiments revealed that while NaOH enhanced the separation efficiency of V₂O₅ and SiO₂, it led to agglomerated products, hindering TiO₂ recovery. In contrast, Na₂CO₃ enabled the production of powdery sintered residues, facilitating the complete separation of anatase/rutile TiO₂ nanoparticles, as confirmed by XRD. By optimizing the sintering-leaching conditions, this method achieves near-total recovery of TiO₂ with retained photocatalytic performance, ensuring its suitability for reuse in applications such as air/water purification or renewable energy systems. This study advances sustainability by repurposing industrial waste into high-performance materials, reducing the energy and resource demands associated with conventional TiO₂ synthesis, and preventing hazardous material leakage into ecosystems. The scalable, low-complexity process aligns with global sustainability goals, including responsible consumption (SDG 12), climate action (SDG 13), and industrial innovation (SDG 9), offering a blueprint for transforming waste streams into valuable resources for a greener economy. Full article

Papaya (Carica papaya L.) is essential for food security, providing economic benefits in tropical and subtropical regions. However, its high water requirements pose challenges, especially in water-scarce areas like Cape Verde. This study hypothesises that reclaimed water (RW) irrigation can promote papaya production and investigates how water can be managed to ensure sustainability and increase agricultural productivity. An experiment was conducted using Carica papaya L. var Solo-nº8, focusing on subsurface drip irrigation (SDI) with RW. Three irrigation treatments were compared, namely, T1: RW with SDI; T2: RW with drip irrigation (DI); and T3: conventional water (CW) with SDI. The study evaluated crop yields and water use efficiency (WUE) over 13 months, monitoring soil and water quality and papaya growth and yields. Despite quality concerns, RW maintained soil fertility and ensured sustainable reuse. Papaya demonstrated high adaptability and productivity under experimental conditions. T1 significantly increased the cumulative fruit yield (69 t/ha) compared to T2 (65 t/ha) and T3 (62.7 t/ha). T1 also had the highest WUE (5.97 kg/m³), demonstrating the effectiveness of RW and SDI in optimising water use. The results indicate that RW can be a viable alternative to conventional water sources, providing new insights into sustainable agricultural practices and improving food security in arid and semi-arid regions. Full article

Due to the rising costs of transportation and the more advanced treatment needed to meet the water demands of the urban population, the costs of potable water tend to increase as cities expand. For some water uses, potable water is not required, such as concrete mixing industries. Previous studies have proven the viability of using reused water in concrete production. In Caju, Rio de Janeiro, four large concrete mixing plants (CMPs) are located close to the Alegria Wastewater Treatment Plant. This study focused on assessing the technical and financial feasibility of reusing these effluents as an alternative source of water for the four CMPs. The alternatives were potable and reused water via two supply methods, water tank trucks and pipelines. All costs were analyzed and projected into the future with the market cost of capital. After comparing the costs, the use of reclaimed water proved to be highly feasible, especially when a using pipeline to supply the CMPs. The present costs for the reclaimed water supply were calculated to be USD 0.99 per m³ for the pipeline alternative and the other alternatives varied in being 5 to 7 times more costly. This water reuse project using pipelines to transport reclaimed water to concrete mixing plants provides a feasible, sustainable alternative water supply in water stressed regions such as Rio de Janeiro. Full article

Water reuse, the beneficial use of highly treated municipal wastewater (reclaimed water), is expanding throughout the United States (U.S.); however, there are currently no federal reclaimed water use regulations, only guidelines. As a result, state policies on reclaimed water vary widely, emphasizing the need for a comprehensive understanding to facilitate coordinated national planning. Our systematic literature review, utilizing an online legal research database, presents an updated overview of U.S. reclaimed water policies from 2004 to 2023. A novel categorization scheme tracks policy changes, highlighting a 38% increase in states regulating reclaimed water between 2004 and 2023. We also created maps of current reclaimed water use regulations across the U.S. including: (1) a national overview of the reclaimed water policy landscape; and (2) documentation of non-food crop and food crop irrigation policies. As of November 2023, 74% of states (37/50) intentionally regulated reclaimed water use. Regions with historically low water scarcity, such as the Midwest, exhibited lower participation rates in reclaimed water regulation than water-scarce regions in the West. Of the 37 states regulating direct reclaimed water use in 2023, all allowed for at least some agricultural uses; 23 permitted non-food and food crop production use, while 14 states have statutory allowances for direct reclaimed water use on non-food crop production. As climate change stresses freshwater resources, our work provides up-to-date information for policymakers to navigate existing reclaimed water use policies. Full article

Reclaimed municipal wastewater is a crucial component in biofuel production, especially in regions experiencing increasing freshwater scarcity. However, accurately estimating the potential for fuel production is challenging because of the uneven distribution of biofuel feedstock regions and wastewater treatment plants (WWTPs). This study assesses the viability of using reclaimed municipal water for algal biomass production in pond systems co-located with WWTPs under scenarios driven by biomass production and based on water transport logistics. We performed state- and county-level analysis of reclaimed water resources throughout the United States based on WWTP facility data. We overlaid these data onto estimated algae facility sites and examined the temporal resource availability to address seasonal variations in cultivation demand. Our findings reveal that 2694 billion liters per year of reclaimed water could potentially be used to produce 42.2 million metric tons (ash-free dry weight) of algal biomass, equivalent to 29.2 billion liters of renewable diesel equivalent (RDe). The use of reclaimed water would double current national water reuse and expand such reuse significantly in 455 counties across the United States. However, when we limit the construction of algae facilities to counties that can fully meet their water demand in order to minimize water transport burdens, the available supply decreases by 80%, to 512 billion liters, resulting in annual production of 12.2 billion liters of RDe, which still doubles current biodiesel production. Our analysis highlights the degree to which the location and flow of WWTPs and water transport affect the deployment of algae biofuel facilities and tradeoffs. These findings underscore the importance of improving the current WWTP infrastructure for reclaimed water reuse, especially in southern states. Full article

The treatment of sludge digestion liquid is a big challenge in wastewater treatment. If treated as normal wastewater, large amounts of nitrogen and phosphorus present in the sludge digestion liquid might be wasted when they could be reused in agricultural irrigation and reduce the consumption of artificial fertilizers. Thus, it is of utmost importance to deliver a simple and feasible strategy to treat sludge digestion liquid for agricultural reuse. In this study, a novel type of anaerobic fluidized bed membrane bioreactor system (US-AnFMBR) was developed by combining an ultrasonic processing unit and biochar in AnFMBR. The improvement of sludge properties, removal of pollutants performance and membrane fouling mitigation were achieved in this novel system. The optimal dose of BC (biochar) was 2.5 g·L⁻¹, and the optimal ultrasonic treatment conditions were 30 min at 26 W. The main contribution of ultrasound was to improve the activity of sludge microorganisms to adsorb and degrade more organic matter present in sewage. The system achieved the removal efficiencies of COD, NH₄⁺-N and PO₄³⁻-P up to 89.41%, 49.29% and 54.83%, respectively, and had a better mitigation effect in terms of membrane fouling. On the one hand, the biochar addition for COD removal performance was mainly manifested in membrane rejection performance. On the other hand, the combination of low-cost biochar and AnFMBR can also provide new ideas for the recycling of agricultural waste for biochar production. However, regarding the removal efficiency of NH₄⁺-N and PO₄³⁻-P, the US-AnFMBR system promoted the activity of starved sludge to preferentially absorb NH₄⁺-N compared with PO₄³⁻-P by statistical analysis. The US-AnFMBR can reduce the viscosity of sludge and release more small molecular substances, thus better mitigating membrane fouling. Long-term operation performance also revealed the excellent stability of the sludge digestion liquid treatment. The US-AnFMBR system achieves the recovery of nitrogen and phosphorus resources for subsequent agricultural recycling, and avoids the eutrophication of water ecosystems. Reclaimed water meets the nutrient requirements of typical crops during the growing season. To a certain extent, carbon emission reductions in agriculture can be achieved. Full article

Due to climate change, 2/3 of the world’s population will face water shortage problems by 2025, while a 50% increase in food production is required in 2050 to feed nine billion people. In addition, the intensified anthropogenic activities have significantly increased water resource pollution. In this condition, wastewater reuse for crop irrigation to reduce water scarcity is currently becoming global, while it often causes soil pollution and heavy metal accumulation in agricultural areas. This situation has increased public concern over its environmental impact. Thus, an integrated framework was conducted to discuss the status of water availability in China, wastewater treatment and reuse in irrigation systems, and the potential health risks. Avenues for new research toward sustainable agriculture were discussed. We emphasize that wastewater reuse reduces the freshwater deficit and increases food productivity. However, adequate treatment should be applied before use to reduce its adverse impacts on human health risks and environmental pollution. Facilities and policies should support more accessible access to reclaimed water used in industries and urban facilities from secondary municipal wastewater treatment plants. This could be a long-term solution to eradicate water scarcity and inefficient water resources in agricultural systems. Full article

Forest water reclamation can improve tree growth and renovate municipal wastewater. Although there are indications that long-term application may exceed forest assimilation capacity, there is limited information on the long-term effects of reclaimed water application on coniferous ecosystems. The purpose of our study was to assess the impacts of prolonged reclaimed water application on forest growth responses and vegetation diversity. We examined the effects of reclaimed water at five water reuse facilities established between 1978 and 2013 in a four-decade time series. We collected tree cores and stem measurements to determine current and retrospective increments. We assessed plant diversity with vegetation surveys. The greatest diameter response observed for reclaimed water amendment compared to controls was 166.1% for western redcedar, while Douglas-fir increased up to 116.4% and ponderosa pine increased up to 100.6%. The minimum response observed was 30.3%. Current annual increments showed that the basal area and volume were significantly greater at long-established facilities for reclaimed-water-amended plots. The understory vegetation diversity declined with application time, while overstory vegetation diversity increased with application time. We conclude that reclaimed water can be a valuable resource to improve forest productivity, but continued application without stocking control may have detrimental effects on forest growth and vegetation diversity. Full article

Wastewater reuse is an activity that reduces pollution from discharges while increasing the available water resources. However, the high financial costs of this activity affect the viability of projects, either because of low water productivity or because of the presence of a cheaper alternative, such as natural water sources. The existence of environmental or social benefits makes reuse a positive option for society for its environmental and social benefits. This leaves the public sector to decide whether the benefit obtained justifies its participation in the development of reuse programs, for which it is necessary to use a tool such as cost-benefit analysis, which combines diverse costs and benefits. This article studies the potential for water reuse in Spain and the importance of informed decision-making, based on information regarding water stress, wastewater reuse, and the case study of the Canal de Isabel II (Madrid). The results confirm the potential of wastewater reuse; agriculture has a water productivity below EUR 1 per cubic meter and industry and services need their own sources of water, but financial constraints prevent the greater use of reclaimed water in all economic sectors and public intervention is necessary to obtain the optimum scenario for society. The case study from Madrid that we have analyzed in this paper shows the importance of considering all factors, since the results of prioritizing the financial criterion would have been detrimental to society, in the form of EUR 200 million in environmental damage, while EUR 740 million of non-financial benefits would make wastewater reuse an advantageous alternative for society, thus justifying the public investment. Full article

The wastewater reuse is an important measure to face water shortage, thus improving the resilience of agricultural production chains. However, treated wastewater can contain residual organic micropollutants residues that may result in crop contamination. Among edible crops, olive is the most important agricultural product in the Mediterranean region. Methods to assess the contamination of organic micropollutants such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in olives are poorly investigated. Given the complexity of olives, this study focused on the development and validation of a method for the simultaneous extraction of PAHs and PCBs from olives, and subsequent analysis by gas chromatography coupled with mass spectrometry detection. Extraction was optimized through a QuEChERS protocol, studying the effect of the extraction solvent (CH₂Cl₂, cyclohexane, CH₃CN) and of the dispersive-solid phase extraction (d-SPE) sorbent (octadecyl silica, Florisil, primary secondary amine, Z-Sep) on the recovery of micropollutants. The best recoveries (94–122%, relative standard deviations below 5%) were obtained using CH₃CN/H₂O and a double purification step with Z-Sep and Florisil. The method developed for PAHs and PCBs, which showed good intra-day (<2.7%) and inter-day (<2.9%) precision and low matrix effect (|ME| < 14%), was applied to the analysis of olives grown by irrigation with reclaimed wastewaters. Full article

The estimation and quantification of external environmental costs (hidden costs) are crucial to sustainability assessments of treated wastewater reuse projects. These costs, however, are rarely considered in economic analysis studies. In this work, monetized life cycle assessment (LCA) and life cycle costing (LCC) were combined into a hybrid model to calculate cradle-to-farm gate external environmental costs (EEC) and internal costs (IC) of producing 1 t of plant-based product irrigated with reclaimed water in a Mediterranean context. The total cost was calculated by combining monetized LCA and LCC results. The results for the crops under consideration were 119.4 €/t for tomatoes, 344.4 €/t for table grapes, and 557 €/t for artichokes. Our findings show that there are significant hidden costs at the farm level, with EEC accounting for 57%, 23%, and 38% of the total cost of tomatoes, table grapes, and artichokes, respectively. Electricity use for water treatment and fertilization generated most of the EEC driven by the global warming, particulate matter, acidification, and fossil resource scarcity impact categories. When compared to groundwater, the higher internal costs of reclaimed water were offset by lower external costs, particularly when supported by low-energy wastewater treatment. This demonstrates that incorporating EEC into economic analyses might generate a better understanding of the profitability of treated wastewater reuse in crop production. In Italy and the Mediterranean region, research on the sustainability of water reuse in irrigation through life cycle thinking is still limited. Using a multi-metric approach, our analysis brought new insights into both economic and environmental performance – and their tradeoff relationships in wastewater reuse for irrigation of agricultural crops. In future research, it would be of interest to use different monetization methods as well as to investigate social externalities to explore their size and role in the total external costs. Full article

Growing concerns about the circular economy and sustainable waste management for civil applications of non-hazardous mineral industrial waste have increased in recent years. Therefore, this study presents a trend analysis of industrial waste generation and treatment during the years of 2010–2020, and focused on promotion policies and regulatory measures for mandatory renewable resources from industrial sources in Taiwan, including reclaimed asphalt pavement (RAP) material, water-quenched blast furnace slag, and ilmenite chlorination furnace slag. According to the official database of the online reported statistics during the period of 2010–2020, approximately three million metric tons per year of renewable resources were totally reused in civil engineering or related cement products, reflecting a balanced supply chain in the domestic market. Among these, water-quenched blast furnace slag accounted for about 90% (about 2.7 million metric tons) in Taiwan. Currently, the legislative framework of sustainable waste management in Taiwan is based on the Waste Management Act and the Resource Recycling Act, but there are some problems with them. In order to effectively reduce environmental loadings and conserve natural resources to mitigate climate change, some recommendations are addressed from different points of view. Full article