Overview
ISO 20466:2024 - Guidance for performance grading of recovered reverse osmosis (RO) membranes for water reuse - establishes a consistent framework for classifying the performance of recovered spiral-wound RO membranes from seawater (SWRO) and brackish water (BWRO) systems. The standard defines what information must accompany a recovered RO membrane, how performance grades are presented, and the minimum data required to support safe and predictable reuse in water reuse applications. ISO 20466:2024 does not prescribe recovery or cleaning methods.
Key topics and requirements
- Scope and applicability: Applies to spiral-wound recovered RO membranes from SWRO and BWRO systems intended for non-potable water reuse.
- Performance grading: Membranes are graded by key performance metrics-salt rejection and flow rate-with classification prefixes to indicate source type (e.g., “S-” for SWRO, “B-” for BWRO). Example grades in the standard include labels such as S-A1 or C1 (introductory examples).
- Required information: Each recovered membrane must include, at minimum:
- Unique serial number
- Grade
- Differential pressure
- Usage history (raw water type, application, years of operation, membrane area)
- Recovered membrane supplier details
- Performance test information (test method, conditions and results)
- Marking and traceability: Permanent human-readable marking on the element plus optional machine-readable identifiers (2D barcode, RFID). Documents should be attached electronically or in print and protected against counterfeiting (PKI/encoded verification suggested).
- Testing and documentation: Performance test methods and conditions are referenced (see Annex A) - suppliers must report test parameters (e.g., feed conditions, temperature, test salt) and measured flow/rejection results.
- Limitations: Recovered membranes graded under ISO 20466 are intended for water reuse but not for potable reuse per ISO 20469.
Practical applications
- Enables reuse pathways such as cascade reuse (e.g., SWRO membrane repurposed for tertiary wastewater treatment), irrigation, industrial boiler feed water, and other non-potable water reuse uses.
- Supports system designers and engineers by providing consistent performance data needed for pump sizing, piping, and process design.
- Promotes circular economy goals by extending membrane life, reducing disposal and manufacturing impacts, and supporting SDGs related to responsible consumption and clean water.
Who should use this standard
- Recovered membrane suppliers and manufacturers
- Water reuse system designers and process engineers
- Wastewater treatment operators and utilities
- Procurement teams, regulators, and certification bodies assessing reclaimed membrane products
Related standards
Keywords: ISO 20466:2024, recovered RO membranes, performance grading, water reuse, spiral-wound, SWRO, BWRO, membrane rejection, flow rate, membrane traceability.