Reuse of wastewater for irrigation and production of slow-release fertilizers in agricultural industry

Italy
Utility – industry symbiosis
The wastewater treatment plants (WWTPs) in Corleone and Marineo have special features for water reuse and nutrient recovery. Corleone has a membrane system and a distribution network for water reuse by local agriculture. Marineo WWTP will be devoted to material recovery, by implementing a process line for the PHA production /extraction as well as the installation of final filters filled with Biochar and zeolites for nutrients adsorption. The Corleone WWTP will be devoted to water reuse in agriculture where an experimental field trial will be conducted for assessment of the field interactions among water-soil-plants. A new industry consortium will be constituted to utilize the full potential of these reuse facilities.
Objective
Demonstrate solutions for: i) Reduction of greenhouse gas (GHG) emissions by improving the wastewater treatment process; ii) Recovery of nitrogen and phosphorus from wastewater by biochar and zeolite filters; iii) Reuse of the recovered nutrients (as slow-release fertilisers) and sewage sludge (as amendments) for agricultural and forest purposes; iv) Extraction of polyhydroxyalkanoates (PHA) from mixed microbial cultures. v) Reuse of treated wastewater for irrigation in agricultural and possibly in public gardens of urban areas.
Sicily case – innovative actions
Nitrogen and phosphorous from wastewater will be recovered by using innovative filters filled with special adsorbents such as biochar and zeolite. Both materials have already been explored as soil amendments and nutrient absorbents. Indeed, due to their high surface area, porosity and presence of charges, both adsorbents are very efficient in adsorbing nutrients improving also soil physical, chemical and biochemical properties. Nutrient-enriched biochar and zeolite from wastewater treatment will be added directly to agricultural soils as slow-release fertilisers. PHA extraction will be done by an innovative protocol, which employs switchable anionic surfactant ammonium laurate. GHG from WWTPs will be reduced by both experimental and mathematical modelling activities. The sewage sludge will be disposed of, after a preliminary treatment, in agriculture and forest. Reuse of treated wastewater for irrigation will be evaluated. The demonstrations will be performed both in full scale WWTPs and pilot plants. Local industries related to water reuse as well as fertiliser production will be part of the project fostering the application of the circular economy concept.
Outcomes
Creation of a new CE value chain with a new market of biomaterials derived from wastewater treatment. Demonstration of best practices for this as basis for further implementation that offer advantages for the local economy connected to wastewater reuse.
Key stakeholders and partners
Local and regional agri-food producers, farms and their associations, biochar technology owners, bioplastic industry; i.e. Mugavero Teresa s.a.s and Marineo and Corleone Municipalities, AMAP SPA, Università degli studi di Palermo.