Water Reuse in Container Washing for the Agro-Food Industry in Eastern Spain

Compensation

Water Recycling and Reuse

Overview

This project aims to significantly reduce the use of potable water in industrial container washing operations within the food sector by implementing an advanced water treatment and recirculation system. The goal is to transform a linear consumption-discharge process into a closed-loop cycle, in which the water used in the washing stage can be recovered, treated using chemical-free technologies, and reused within the same process. This strategy promotes a structural improvement in water efficiency while also reducing the volume of effluents and the costs associated with water supply and treatment.

The proposed solution is based on treatment technologies that combine physical solid separation, advanced oxidation treatment, and disinfection without the use of chlorine, enabling compliance with food industry requirements regarding safety and hygiene. The system operates automatically, with real-time monitoring of critical quality parameters of the treated water, ensuring its safe and efficient reuse.

Problem and Causes

Food plants use large volumes of potable water to wash containers, plastic crates, reusable bottles, and other vessels that are part of the product logistics chain. Currently, this water is used only once and then discharged as graywater, either untreated or only partially treated. This creates three main problems:

Intensive and unsustainable use of potable water,
generation of effluents with contaminant loads that require additional management,
exposure to regulatory and reputational risks related to water efficiency and environmental compliance.

The root causes of this problem include the lack of technical solutions to close the water cycle within the same operation, the perception that graywater from washing is of low quality and difficult to treat, and the absence of regulatory or financial incentives to adopt circular solutions

Health Effects

Mitigation Measures and Solutions

The proposed solution involves installing a real-time treatment and recirculation system for wash water, integrated in a modular fashion within the production line without interfering with critical hygiene or quality processes. This system is designed to operate without the addition of chemicals and with low energy consumption, making it a low-impact, high-efficiency solution.

Mechanical pre-filtration: performed through meshes and solid retention filters with controlled granulometry, allowing removal of suspended coarse particles, organic residues, or container labels. This stage also includes a grease trap and hydraulic separator to prevent downstream saturation.
Advanced electrochemical oxidation treatment: this technology generates oxidizing radicals in situ that degrade organic compounds present in the wash water (food residues, biofilm, detergents). A key advantage is that it does not require the addition of reagents nor does it produce secondary by-products.
Final disinfection without chlorine: instead of hypochlorite or other conventional biocides, the system uses disinfection techniques such as UV radiation, activated peroxides, or electrokinetic methods, which ensure a safe microbial load for reuse in indirect-contact processes.
Automatic reinjection of treated water: through a direct and automated connection, the water is redistributed to pre-wash or initial rinse systems. This recirculation is regulated based on the load level and prior contact time, avoiding accumulation risks.
Continuous monitoring system: high-precision digital sensors measure real-time parameters such as turbidity, conductivity, pH, temperature, ORP, and possible disinfectant residues, integrating operation alerts and automatic traceability.

This intervention enables up to an 80% reduction in the use of primary water sources, more than a 70% decrease in effluent volume, and avoidance of chemical products in sanitation processes, significantly reducing operating costs, energy consumption, and regulatory risks related to discharge or food safety.

Sustainable Development Goals (SDGs)

SDG 6 – Clean Water and Sanitation: Improves water use efficiency and reduces contaminant discharges.

SDG 9 – Industry, Innovation, and Infrastructure: Introduces clean and efficient technologies into a key industrial process.

SDG 12 – Responsible Consumption and Production: Transforms a linear process into a circular one, reducing waste.

SDG 13 – Climate Action: Reduces indirect emissions associated with pumping, transport, and external water treatment.

SDG 17 – Partnerships for the Goals: Promotes collaborations between industry, technology providers, and certifiers.

Project Information

Country:

Spain

Implementation

The project is implemented in the eastern region of Spain (Levante), where multiple fruit and vegetable packaging plants operate in areas facing high structural water stress, such as the Segura River Basin, the Júcar River Basin, and coastal zones within the Vinalopó-Alacantí Water District. These basins are characterized by low natural water availability, high agricultural and industrial pressure, and increasing vulnerability to climate change.

By reducing the use of potable water sourced from municipal networks or groundwater extractions, and by minimizing industrial discharges, the project contributes to improving the local water balance, alleviating overexploitation of coastal aquifers, and reducing pressure on wastewater infrastructure.

This approach aligns with the priorities of the Spanish National Hydrological Plan and the goals of the EU Water Framework Directive, by promoting on-site water reuse and efficiency in key productive sectors of the region.

Technologies or actions applied:

Solid removal through mechanical filters and sedimentation units acting as a primary barrier to eliminate large particles and floating materials present in wash water.
Advanced oxidation of organic matter through electrochemical or catalytic processes generating oxidants in situ, eliminating detergent residues, biofilm, and food waste without external chemicals.
• UV disinfection or selective oxidation without chlorine, ensuring pathogen removal with harmless technologies that leave no dangerous residues nor affect materials in the washing circuit.
System automation with quality sensors integrated into a digital platform enabling autonomous operation with alarms and control of critical parameters, including retention times and recirculation rates.

Monitoring plan:

Measurement of incoming, recirculated, and discharged flows using electromagnetic flowmeters and ultrasonic sensors installed at strategic points of the system.
Logging of critical water quality parameters: COD, turbidity, pH, conductivity, and ORP, automatically recorded and auditable via a web-based platform.
Preventive maintenance control and digital operation logging, with performance indicators (KPIs) and event logs for operational analysis.

Partnerships or implementing actors:

Food plant industrial operators trained in recirculation system operation and monitoring.
Advanced treatment technology providers specialized in chemical-free processes and compliance with food industry standards.
External laboratories and certifiers (AWS, SCS, CDP) responsible for validating water benefits and ensuring traceability under VWBA and WQBA methodologies.

Understanding the Project

Water reuse in industrial processes is a key strategy to move toward more sustainable water management, especially in sectors like food processing, where sanitary and quality requirements necessitate intensive resource use. This project offers a concrete solution to transform one of the most critical production stages—container washing—into an opportunity for efficiency, savings, and circularity.

The proposed model comprehensively addresses technical, operational, and governance aspects of water management. On one hand, it introduces physical-chemical treatment technologies and chemical-free disinfection, removing common barriers to recirculation in food environments. On the other hand, it enables full control of the system through automation and smart sensors, ensuring quality parameters remain within limits set by regulations and internal protocols.

At the plant level, implementing this solution brings multiple positive impacts:

Significantly decreases the volume of water extracted from primary sources.
Reduces effluent volume and associated pollutant load.
Improves traceability and regulatory compliance.
Cuts operating costs for water, chemicals, and energy.
Contributes to corporate sustainability, reputation, and circular economy goals.

From an environmental perspective, the intervention delivers concrete benefits to basin water balance and enhances operational resilience to water stress or tariff increases. Socially, the project can align with corporate responsibility strategies through staff training, partnerships with local organizations, or replication in nearby communities.

In summary, this intervention not only solves a technical issue but also structurally transforms how water is managed within a food processing plant. Its replicability, relatively low cost, and high return in sustainability and compliance make it an effective tool for companies seeking leadership in water stewardship and ecological transition.