Non Technical Summary
Water scarcity is a growing challenge for agriculture in California and other arid regions. Recycled water (treated wastewater) has strong potential as an alternative irrigation source, but concerns about contaminants of emerging concern (CECs), such as pharmaceuticals and personal care products, limit its broader use for food production. This project aims to address these concerns by developing practical, on-farm solutions that improve the safety and reliability of recycled water for irrigating food crops.In this project, a multidisciplinary team of environmental and agricultural engineers from the University of California, Riverside will work together to advance innovative recycled water treatment and irrigation management strategies. The research will combine water treatment engineering with irrigation management to reduce the presence and accumulation of CECs in crops irrigated with recycled water.From a water treatment perspective, the team will design and develop a mobile treatment system that can be used directly on farms to treat recycled water before irrigation. This system uses a light-based process to break down contaminants, making recycled water safer for agricultural use. From an irrigation management perspective, greenhouse studies will evaluate how adjusting irrigation practices based on crop growth stages can further reduce the movement of contaminants into the edible portions of plants.The most promising treatment and management strategies will be tested in field-scale irrigation demonstrations to evaluate their real-world performance and practicality. Together, these efforts aim to transform recycled water from a potential source of concern into a safe, sustainable water supply that can help supplement limited freshwater resources.The project team will actively share results with growers, water managers, and other stakeholders through events at the South Coast Research and Extension Center in Irvine. Extension publications and online resources will present the findings in clear, non-technical language to support adoption of these practices. By integrating research and outreach, this project will help strengthen agricultural resilience, protect food safety, and promote sustainable water use in California and beyond.

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
111	0210	2050	50%
111	0210	2020	50%

Knowledge Area
111 - Conservation and Efficient Use of Water;

Subject Of Investigation
0210 - Water resources;

Field Of Science
2020 - Engineering; 2050 - Hydrology;

Goals / Objectives
The overall objective of this project is to enhance the sustainability of recycled water irrigation for safe food production by integrating persulfate photolysis water treatment with an irrigation water source alteration approach. Our specific objectives are to:Develop a plant growth stage-based water source alteration irrigation management approach to mitigate the accumulation of selected CECs in the edible parts of multiple crops under greenhouse conditions.Design and develop a novel mobile persulfate photolysis water treatment reactor to remove the selected CECs from recycled water.Evaluate the integration of the plant growth stage-based water alteration approach with persulfate photolysis treatment under greenhouse conditions.Implement and assess the efficacy of the mobile persulfate photolysis water treatment reactor under field conditions.

Project Methods
Task 1. CEC Accumulation, Plant Growth Stages, and Plant Growth-Based Water Treatment Using Persulfate Photolysis (Greenhouse Experiments)Greenhouse experiments will be conducted to (i) evaluate irrigation water alteration strategies and (ii) determine the fate and transport of selected chemicals of emerging concern (CECs) within the soil-plant system across different plant growth stages.Task 2. Development of a Mobile Persulfate Photolysis Reactor for CEC RemovalA mobile, flow-through water treatment system will be developed to treat recycled irrigation water using persulfate photolysis for the removal of CECs.Task 3. Field Implementation and Demonstration of the Mobile Persulfate Photolysis ReactorFollowing completion of Tasks 1 and 2, a field demonstration project will be conducted to evaluate and showcase the integrated water alteration and treatment management strategy and the mobile treatment technology developed in this study under real-world irrigation conditions.Task 4. Outreach and Extension Education ActivitiesA dedicated project webpage will be developed and hosted on the PI's website and updated regularly throughout the project. Outreach activities will include participation (whenever possible) in events at the South Coast Research and Extension Center (SCREC) in Irvine, where research plots and the mobile treatment reactor will be demonstrated.In addition, multiple extension publications will be produced to disseminate guidance on recycled water alteration strategies and persulfate photolysis treatment technology.