Agriculture: a prototype for crop irrigation and fertilization with purified wastewater Agriculture: a prototype for crop irrigation and fertilization with purified wastewater

31 March 2022 Last Updated: 14 September 2022

ENEA and University of Bologna, in collaboration with Hera Group and Irritec, have developed a technologically advanced prototype which uses purified wastewater for crop irrigation and fertilization, saving considerable amounts of water, providing nutrients which substitute chemical fertilizers and improving environmental sustainability and quality of the water purification chain. The innovative prototype, which is part of the project Value CE-IN, funded by the Emilia-Romagna Region and the Development and Cohesion Fund, was presented at the World Water Day on 22 March.

The demonstration prototype, built at the Hera Group's purification plant in Cesena, was tested in an experimental field on 120 crops including 66 peach trees and 54 industrial tomatoes. The results of the experimental phase confirmed the good quality of the water purified for agricultural purposes.

"The results of the project, coordinated by ENEA, support the application of the prototype to all purification plants and the dissemination of water reuse practices benefiting all stakeholders in the supply chain - from plant managers to reclamation consortia up to the automation, control and measurement sector - with the aim of guaranteeing an unconventional and safe water resource and at the same time providing crops with nutrients, in line with the new community guidelines in force since 2023[1]”, pointed out project coordinator Luigi Petta, Head of the ENEA Laboratory of Technologies for an Efficient use and Management of Water and Wastewater.

According to recent studies[2], in our country per capita fresh water withdrawals for agricultural use accounts for about 50% of the overall water demand; in addition, water scarcity, an increasingly frequent phenomenon due to climate change, represents significant risk to over one third of national agricultural production, negatively affecting both quantity and quality of crops, estimated at around one billion euro per year on average.

The results of industrial research, to be confirmed by further studies, show the feasibility of circular economy practices and industrial symbiosis that favor the conversion of purification plants into actual biorefineries- from which to recover the primary water source, secondary products with high added value, like soil improvers and fertilizers effective at providing nutrient supply, including nitrogen, phosphorus and potassium- with decreased use of synthetic chemical fertilizers.

"The research conducted has highlighted the high potential of wastewater reuse for fertigation, which has quantitative and nutritional advantages, using smart technologies and materials improving irrigation and precision fertilization management. Furthermore, the verification of the effects of direct reuse of secondary and tertiary effluents on the soil-plant system has shown, in the studies conducted so far, its safety and sustainability", pointed out Attilio Toscano, professor of agricultural hydraulics and coordinator of the experimental activities conducted by CIRI FRAME, the Interdepartmental Center for Industrial Research in Renewable Sources, Environment, Sea and Energy of the University of Bologna.

"This experimentation is part of the Hera Group's strategies for resource efficiency, reduced consumption, circularity and wastewater reuse solutions. The Cesena treatment plant is a concrete example of circular water management, both in terms of a concrete and safe way of reusing purified wastewater for agricultural purposes, and to enhance and recover secondary products from sewage sludge ”, pointed out Susanna Zucchelli, Water Manager at the Hera Group.

"Thanks to the results achieved, the project aims to act as a catalyst for agreements between institutions and companies in the supply chain- already involved in the project development- to implement these practices on a full scale, starting from the best practice developed in Cesena as part of the project ”, concluded Petta.