Cost–Benefit Analysis of Wastewater Reuse in Puglia, Southern Italy

Benefit Analysis of Economic and Social Water Supply in Xi’an Based on the Emergy Method

In order to manage regional water resources efficiently and sustainably and promote the rational utilization of water resources, it is necessary to evaluate the water-supply benefit reasonably. On the basis of emergy theory, this paper constructs the water-supply-benefit model of economic (industry, agriculture, and the tertiary industry) and social (domestic, employment security, entertainment, scientific research) systems. Taking Xi’an from 2014 to 2020 as an example, by analyzing the energy flow of each system and the multisource water transformities, the water contribution rate, the water-supply benefit, and the unit-water-resource value in each system are calculated. For the water-supply benefits: Industry > Agriculture > Domestic > Tertiary industry > Employment Security > Entertainment > Scientific research. For the unit-water-resource values: Industry > Tertiary industry > Agriculture > Domestic > Entertainment > Employment security > Scientific research. In the economic system, the water-supply benefit and the unit-water value of industry were always the largest, followed by agriculture and the tertiary industry. However, the Pearson correlation coefficient between the water contribution rate and the output of the industrial system was only 0.52, which was less than that of other production industries, which indicates that there might be a waste of water and that industrial water conservation needs to be further strengthened. In the social system, the domestic-water-supply benefits and the water-resource value were the largest. This is because water resources, as a basic resource, always affect people’s health and quality of life.

Feasibility Study of Water Reclamation Projects in Industrial Parks Incorporating Environmental Benefits: A Case Study in Chonburi, Thailand

Financial feasibility is usually a concern in water reclamation projects. Aside from internal benefits, water reclamation in industrial parks delivers health and environmental benefits not normally considered in cost–benefit analyses (CBA). This study investigated the influence of environmental benefits on the feasibility of water reclamation projects with flow rate scenarios in accordance with industrial parks in Chonburi, Thailand. CBAs of water reclamation plants for industrial water supply, consisting of ultrafiltration (UF) and reverse osmosis (RO), with flow rates of 5200, 10,000, 15,000, and 25,000 m3/day and discount rates of 3%, 5%, 7%, 9% and 11% were conducted. Considering only the direct costs and benefits, none of the projects were financially feasible. However, when the environmental benefits were included, the projects became profitable in all cases except those with a flow rate of 5200 m3/day and discount rates of 5%, 7%, 9%, and 11% and those with flow rates of 10,000 and 25,000 m3/day and an 11% discount rate. Further, CBAs of water reclamation projects in industrial parks for irrigation were conducted with post-treatment processes consisting of sand filtration and chlorine disinfection for flow rates of 240, 480, 2400, 3600, and 4800 m3/day. The projects are profitable, regardless of environmental benefits.

Treated Unconventional Waters Combined with Different Irrigation Strategies Affect 1H NMR Metabolic Profile of a Monovarietal Extra Virgin Olive Oil

The agricultural sector is facing a decrease in water supply and water quality at a global level and this is a problem that strictly affects all the Mediterranean olive growing areas. The aim of this work was to evaluate, for the first time, by NMR Spectroscopy and multivariate data analysis the metabolic profiling of the oils produced under different irrigation schemes. Arbosana olive oils were obtained from the use of saline reclaimed water (RW) and treated municipal wastewater (DW), combined with: full irrigation (FI) and regulated deficit irrigation (RDI). The results show a higher relative content of saturated fatty acids in EVOOs obtained from RDI strategy, regardless of the water source. Moreover, an increase in unsaturated fatty acids, a ω6/ω3 ratio content was observed in EVOOs obtained from RW when compared with DW water. Furthermore, the RW–RDI showed an increase in secoiridoid derivatives and hydroperoxides with respect to DW–RDI. A sustainable irrigation management, by combining a deficit irrigation strategy and saline reclaimed water source, could be crucial in order to overcome the problem of water scarcity and to guarantee the olive oil nutraceutical properties. The 1H NMR-based metabolomic approach proved a powerful and versatile tool for this specific investigation.

Financial and Economic Investment Evaluation of Wastewater Treatment Plant

Improved Cost-Benefit Analysis (CBA) analysis requires a broader analytical framework, in order to perceive each project individually from the perspective of potentially measurable and significant effects on the environment and society as a whole. The main goal of our paper is to assess the financial and economic justification for variant V3 (as the most technically optimal) of the wastewater treatment plant (WWTP) construction project in Nov Dojran, North Macedonia, with the purpose of advancing municipal infrastructure and environmental benefits from improved water treatment. Based on the economic analysis conducted, we conclude that the investment in the WWTP project is justified, because the economic internal rate of return is higher than the opportunity cost of capital (EIRR = 16.38%), the economic net present value is higher than 0, and EBCR (benefit-cost ratio) is greater than 1 (EBCR = 2.11). The highest environmental benefit of 49.2% in total environmental benefits is associated with nitrogen, while phosphorus is the next pollutant in the structure of environmental benefits at 46.1%. The environmental benefits of removing biological oxygen demand (BOD) and chemical oxygen demand (COD) are significantly less important, despite the removal of significant amounts of these pollutants during treatment. The situation is similar with suspended particles.

Promoting Urban Agriculture and Its Opportunities and Challenges—A Global Review

Multifunctionality of urban agriculture can support the resolve of many urban challenges. Therefore, it is vital to understand the contribution of academic studies on urban agriculture practices as scientific information. The present study followed a systematic literature review based on the PRISMA method. Finally, 54 identified articles were analyzed. The review study mainly examined the contribution of academic literature on urban agriculture under four dimensions: the socio-economic context of the country, type of agriculture model, opportunities, and challenges. The results revealed the focus of academic literature on urban agriculture to show favoritism toward developed countries’ community gardens. Moreover, the leading academic focus on this discipline identifies multifunctionality. People’s motivations in developed countries tend to favor social, health-related, and educational benefits of urban agriculture; however, in developing countries, urban agriculture is more related to economic and ecological needs. Challenges for urban agriculture are also different among developed and developing countries. Nevertheless, existing academic studies have given comparatively less attention to identifying challenges, benefit groups of urban agriculture, and government support. Since urban agriculture is highly reliant on local factors, studying more about opportunities and challenges for urban agriculture under different socio-economic contexts and different agriculture models could be more beneficial to connect farming practices in cities with urban planning. Therefore, to make an adequate academic contribution to urban sustainability, future urban agriculture studies need to be more holistic.

Reclaimed Water for Vineyard Irrigation in a Mediterranean Context: Life Cycle Environmental Impacts, Life Cycle Costs, and Eco-Efficiency

The agricultural sector in the Mediterranean region, is increasingly using reclaimed water as an additional source for irrigation. However, there is a limited number of case studies about product-based life cycle analysis to ensure that the overall benefits of reclaimed water do indeed outweigh the impacts. The Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) methods are used in this study to investigate the environmental impacts and costs of vineyard cropping systems when tertiary reclaimed water is used as a supplementary source of irrigation water (integrated system). The conventional production system utilizing 100% groundwater was used as a reference system. As a proxy for sustainability, eco-efficiency, which combines economic and environmental performance, was assessed. The LCA revealed that the integrated system could reduce the net environmental impact by 23.8% due to lower consumption of irrigation water (−50%), electricity (−27.7%), and chemical fertilizers (−22.6%). Nevertheless, trade-offs between economics and the environment occurred as an integrated system is associated with higher life cycle costs and lower economic returns due to lower crop yield (−9.1%). The combined eco-efficiency assessment (ratio of economic value added to total environmental impact) revealed that the integrated system outperformed in terms of eco-efficiency by 12.6% due to lower environmental impacts. These results confirmed that reclaimed water could help to ensure an economically profitable yield with net environmental benefits. Our results provided an up-to-date and consistent life cycle analysis contributing to the creation of a valuable knowledge base for the associated costs and benefits of vineyard cultivation with treated wastewater.

Treated wastewater reuse for irrigation: Pros and cons

The appropriateness of using treated wastewater for crop or agricultural irrigation remains a bone of contention among experts and policymakers. Here, we outline and analyze not only the benefits but also the drawbacks of such a practice in order to suggest a way forward. To ensure that our review reflects the state-of-the-art in terms of technological advances and best practices, only literature published in the last decade is considered except for literature on the history of reuse. The review begins by highlighting growing water scarcity, the history of wastewater reuse in agriculture, and the limitations of existing studies. A short overview of the approach used in the write-up is outlined after the introduction. It then proceeds with an in-depth look at three broad areas: environmental impacts, public health impacts, and economic impacts. In terms of environmental impacts, effects on soil quality, water resources, plant growth, and soil microbial communities are analyzed. For each sub-area, the positive effects are described before the negative ones. The same approach is then applied to public health impacts, the focus of which is on human exposure to heavy metals and pathogens, and economic impacts, which are assessed with particular reference to investment cost, financial benefit to wastewater treatment plants (WWTPs), farm expenditure and income. Having weighed the advantages and disadvantages in each area, innovative measures are proposed for optimizing the benefits and mitigating the drawbacks of using treated wastewater for crop irrigation. Special consideration was given to contaminants of emerging concern and the known or perceived environmental and health risks associated with these contaminants.

Variations of Groundwater Dynamics in Alluvial Aquifers with Reclaimed Water Restoring the Overlying River, Beijing, China

Some of the rivers in northern China are dried, and reclaimed water (RW) is used to restore these degraded river ecosystems, during which the RW could recharge the aquifer by river bank infiltration. From 2007 to 2018, 2.78 × 108 m3 of RW has been replenished to the dried Chaobai River (Shunyi reach), Beijing, China, which is located on the edge of one depression cone in groundwater caused by groundwater over-pumping. The groundwater hydrodynamic variations and the flow path of the RW were identified by eight-year hydrological, hydrochemical, and stable isotopic data, together with multivariate statistical analysis. The RW infiltration drastically impacts the groundwater dynamics with a spatiotemporal variation. The 30-m depth groundwater levels at Perennial intake reach increased quickly around 3 m after 2007, which indicated that they were dominated by RW infiltration. Other 30-m depth groundwater levels were controlled by precipitation recharge from 2007 to 2011, showing significant seasonal variations. In 2012, with more RW transferred to the river, the hydrodynamic impact of the RW on 30-m depth aquifer expanded downstream. However, the 50-m and 80-m depth groundwater levels showed decreasing trend with seasonal variations, due to groundwater pumping. The 30-m depth aquifer was mainly recharged by RW, being evidenced by the enriched δ2H and δ18O. The depleted δ2H and δ18O of the 50-m and 80-m depth groundwater indicated that they were dominated by regional groundwater with meteoric origin. The heterogenous properties of the multi-layer alluvial aquifer offer the preferential flow path for RW transport in the aquifers. The proportion of the RW in the aquifers decreases with depth that was calculated by the chloride conservative mixing model. The increased lateral hydraulic gradient (0.43%) contributes to the RW transport in the 30-m depth aquifer. RW usage changed 30-m depth groundwater type from Ca·Mg-HCO3 to Na·Ca·Mg-HCO3·Cl. RW preferentially recharged the 50-m and 80-m depth aquifers by vertical leakage.

Environmental Benefits and Economical Sustainability of Urban Wastewater Reuse for Irrigation—A Cost-Benefit Analysis of an Existing Reuse Project in Puglia, Italy

Besides benefits associated to increased water availability for irrigation, reuse projects of urban water can also provide positive environmental impacts, as they contribute to improve water quality of the receiving bodies by diverting wastewater from their outlet. This represents a typical win-win situation where significant synergies can be achieved between urban and agricultural sector, and the environment. These favorable conditions, however, do not necessarily imply that water reuse is either feasible from an economic perspective nor that the underlying supply chain is going to be triggered, if certain conditions are not met. Cost-Benefit Analysis (CBA) is considered a sound, theoretically well-grounded tool to analyze the financial and economical sustainability of an investment. The paper presents the CBA of an existing reuse scheme in Puglia, in southern Italy, reclaiming wastewater for irrigation from a coastal area with growing recreational, beach-related activities. Supported by operational data, official statistics and sector documents, the CBA reveals that in almost all scenarios the existence of environmental benefits must be invoked in order to consider the project economically sustainable. Coherent screening of the different impacts, isolating the ones that are applicable to the specific case-study, shows that these benefits are mainly non-use benefits related to the aesthetic enjoyment of clean water in the reclaimed stretch of coastline where wastewater discharge may no longer take place or take place in a way that significantly reduce seawater pollution.

Ripening Indices, Olive Yield and Oil Quality in Response to Irrigation With Saline Reclaimed Water and Deficit Strategies

The 70% worldwide surface of olive orchards is irrigated. The evaluation of non-conventional water resources and water-saving techniques has gained importance during the last decades in arid and semiarid environments. This study evaluated the effects of irrigation with two water sources: low-cost water DEsalination and SEnsoR Technology (DESERT) desalinated water (DW) EC_w ∼1 dS m^-1) and reclaimed water (RW) (EC_w ∼ 3 dS m^-1) combined with two irrigation strategies: full irrigation (FI) (100% of ET_c) and regulated deficit irrigation (RDI, 50% of ET_c) on fruit yield, ripening indices, and oil yield and quality of olive trees cv Arbosana planted in Mediterranean conditions. Our results showed that RW without water restrictions increased the fruit yield by 35% due to a slight increase in the fruit weight and, mainly, to a greater fruit set than the control trees; although this did not result in a higher oil yield (g tree^-1) since the oil content per fruit dry weight was reduced. The RDI strategy did not decrease the fruit yield despite the fact that olive weight tended to decrease, and it increased the oil yield by ∼14.5%. The combination of both stresses (RW and RDI) neither decreased the fruit yield; however, it significantly reduced oil yield (25% less in 2018) since oil content per fruit dry weight was strongly reduced (40%) compared to control trees. Both RDI treatments, regardless water source, determined acidity levels in olive paste lower than in FI treatments; however, it reduced oil extractability and fatty yield. The finding about oil quality indicated that olive exposure to RW, regardless of the water amount, decreased oil quality mainly due to the reduction of oleic acid and the increase of C18:2/C18:3 ratio and peroxides; on the contrary, both RW and RDI improved the total polyphenols. In all cases, the parameters met the legislation. In short, with appropriate management, RW and RDI have great potential to manage oil olive production; nevertheless, studies subjected to long-term use of these techniques should be experienced to ensure the sustainability of oil yields and quality.

Assessing Reclaimed Urban Wastewater for Reuse in Agriculture: Technical and Economic Concerns for Mediterranean Regions

Direct reuse of treated wastewater can offer a realistic supply alternative for irrigation in Mediterranean areas. In this study, we conducted a spatial cost-benefit analysis to quantify and locate the volume of technically and economically feasible and readily available reclaimed urban wastewater. We considered the case of Puglia (Italy) and the results are discussed in terms of the implications for policy-making and pointing out future research needs. The results showed that the main technical barrier is the shortness of the irrigation season. On the other hand, the main economic concern is related to filtration followed by lack of conveyance systems. While our results are based on estimates, future research should try to include practical experiments based on actual data. Further research should also address the issue of transaction costs by establishing the obligations of wastewater treatment plants to deliver reclaimed water to farmers.

Modelling environmental impacts of treated municipal wastewater reuse for tree crops irrigation in the Mediterranean coastal region

Wastewater reuse provides valuable solutions to solve the societal challenges of decreasing availability and limiting access to secure water resources. The present study quantifies the environmental performance of nectarine orchards irrigation using treated municipal wastewater (TMW) and surface water using a unique dataset based on field experimental data. Climate change, toxicity (for human and freshwater), eutrophication (marine and freshwater) and acidification impacts were analysed using the impact assessment method suggested by the International Reference Life Cycle Data System (ILCD). The water footprint associated to the life cycles of each system has been estimated using the Available WAter REmaining (AWARE) method. Monte Carlo simulation was used to assess data uncertainty. The irrigation of nectarine orchards using TMW performs better than the irrigation using surface water for eutrophication impact categories. Compared with surface water resources, the potential impacts of TMW reuse in agriculture on climate change and toxicity are affected by the wastewater treatment phase (WWT). Only eutrophication and acidification burdens are generated by in-field substitution of surface water with TMW. Considering human and ecosystem water demand, the irrigation with TMW increases water consumption of 19.12 m³ per kg of nectarine produced. Whereas, it shows a positive contribution to water stress (-0.19 m³) if only human water demand is considered. This study provides important results that allow for a better understanding of the potential environmental consequences of TMW reuse in agriculture. It suggests that embracing the type of WWTs, the replacement of fertilizers, the effects on water scarcity and ecosystem quality might be useful to redefine water reuse regulations and increase public acceptance for the reuse of TMW in agriculture. Moreover, this study reveals the need for developing consensus and standardized guidance for life cycle analysis of water reuse applications.