The reuse of reclaimed water for irrigation around the Mediterranean Rim: a step towards a more virtuous cycle?

The successes and failures of water reuse schemes are shaped by complex interrelationships between technological, economic, and socio-political factors. However, it has long been recognized that the main challenges to more effective water management are largely social rather than technical. This article reviews the recent literature (2007–2017) to analyze driving factors associated with farmers’ concerns and public perception of reclaimed wastewater for irrigation. The aim of the paper is to synthetize how both environmental and health risks and the yuck factor could be addressed in order to promote mutual understanding between farmers and the public. Results show: (1) how farmers and the public perceive environmental and health risks in a similar way, (2) how the yuck factor is more noticeable for the public than farmers, and (3) how constructed wetlands, reclaimed water exchange consortiums, product certification, and direct site visits to water reuse infrastructure could be promoted in order to foster understanding between farmers and the public. The article concludes by providing key research questions for managers and public authorities relating to how to focus on the study of technical and social issues related to water reuse.

Section: Introductionmentioning

confidence: 99%

Risk-Yuck Factor Nexus in Reclaimed Wastewater for Irrigation: Comparing Farmers’ Attitudes and Public Perception

Ricart

Rico

Palom

2019

“…Moreover, E. coli contamination on tomato and eggplant never reached significant values by using WW by both option systems. Based on several experiences in different Mediterranean countries, it is expected that rapidly expanding water-recycling practices will quickly provide sustainable, low-energy, and cost-effective options to improve water availability based on criteria of quality and recycling capacity [29] but to provide a more comprehensive understanding of the health risks of wastewater use in agriculture, future research should consider multiple exposure routes, long-term health implications, and increase the range of contaminants studied, particularly in regions heavily dependent on wastewater irrigation [30]. Within the database of WWTPs , used in the study to assess the potential of the reuse practice in Sicily, 14 systems were analysed in terms of physical and chemical quality of the produced TW.…”

Section: Results Of the Risk Assessment Analysis For Selected Wwtps Imentioning

confidence: 99%

How to Overcome Barriers for Wastewater Agricultural Reuse in Sicily (Italy)?

Ventura

Consoli

Barbagallo

et al. 2019

This study reports an up-to-date summary of the principal barriers still limiting reclaimed water use for agriculture in Italy, and particularly in Sicily. Moreover, it provides a geographic informative system (GIS)-based procedure for evaluating the potential treated wastewater (TW) reuse in the Sicilian region as a decision support system for its management. The survey, based on possible economic, morphologic, and design solutions, evidenced a feasible integration of several wastewater treatment plants (WWTPs) with irrigation areas, allowing the water availability enhancement. Overall, the potential volume of TW by WWTPs (connected to irrigation districts) is 163 × 106 m3 year−1, while the water deficit is 66 × 106 m3 year−1. The feasibility of TW reuse in Sicily was also analysed at the light of the World Health Organization microbial risk assessment. Escherichia coli (E. coli) analyses mostly accomplished these guidelines while conflicting with the restrictive Italian standards. Despite several limiting factors (restrictive legislations, high distance and unfavourable slope between WWTPs and irrigable areas, high monitoring and distribution costs) still hamper the exploitation of reclaimed water use in Sicilian agriculture, some solutions were identified to implement this practice.

“…In view of these results, a reduction in fertiliser usage on the main crops and the reuse of treated wastewater from WWTPs were simulated as potential measures for reducing nutrient loads and concentrations. In a circular economy, wastewater should no longer be considered as waste, but as a new resource [49][50][51]. Although several barriers to this exist in basins experiencing water shortage, such as the Rio Mannu, such as public perception [52], the level of contaminants [53], especially the emerging pollutants, and economic aspects, the use of treated wastewater for irrigation may represent a new source of water for agriculture.…”

Section: Discussionmentioning

confidence: 99%

Source Apportionment of Nutrient Loads to a Mediterranean River and Potential Mitigation Measures

Girolamo

Porto

2020

The aims of the study were to quantify nutrient loads from point and diffuse pollution sources in the Rio Mannu stream and to simulate mitigation measures for reducing nutrient loads delivered to the Santa Gilla wetland. The Soil and Water Assessment Tool model was used for simulating hydrology, nutrient balance and water quality. At the basin scale, the input from fertilisers was 80.3 kg ha−1 year−1 total nitrogen (TN) (87.6% of the total input) and 27.6 kg ha−1 year−1 of total phosphorus (TP) (99.8% of the total input). Atmospheric deposition and biological N-fixation together accounted for about 12% of the total TN input. The TN and TP from wastewater treatment plants (WWTPs) were about 14.2 t year−1 and 3.1 t year−1, respectively. Nutrient loads delivered to the river system differed among the sub-basins, with TP ranging from 0.2 kg ha−1 year−1 to 2.7 kg ha−1 year−1, and the sum of organic N and NO3-N ranging from 1.8 kg ha−1 year−1 to 22.9 kg ha−1 year−1. Under high flow conditions, NO3-N and TP accounted for 89% and 99% of the total load, respectively. The low flow contribution to the total load was very low, with NO3-N and TP accounting for 2.8% and 0.7%, respectively. However, the natural hydrological regime in the study area is intermittent, and low flow represents a critical condition for the water quality due to the high concentrations of TP and NO3-N from WWTP discharge. To improve the water quality, the reuse of treated wastewater from three WWTPs for irrigation purposes on olive cultivation, coupled with a 20% reduction in fertiliser application, was simulated. The results showed a reduction in nutrient loads at the outlet for all hydrological conditions. However, additional measures are needed for improving water quality.