Marker-Based Membrane Integrity Testing During Filtration

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Solution Overview

Problem

Existing methods for membrane integrity testing, such as the bubble-decay method, are inadequate for ceramic membranes, as they cannot accurately measure breaches larger than 3 µm, leading to inefficiencies and increased costs due to system shutdowns.

Innovation Solution

A marker-based direct integrity testing method that allows for non-destructive assessment of membrane integrity by dosing a feed fluid with challenge particles, measuring filtrate and feed concentrations, and calculating log removal values, enabling testing while the system is operational.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the bubble-decay method is used for membrane integrity testing, then the system can operate continuously, but the measurement precision is insufficient to detect breaches greater than 3 µm in ceramic membranes

Engineering Contradiction:
Improvecontinuous operationVSAvoidbreach detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent introduces marker particles as an intermediary substance to enable precise detection of membrane breaches. These particles are dosed into the feed stream and their presence in the permeate indicates membrane integrity issues. The marker particles serve as a mediator between the membrane structure and the detection system, allowing continuous monitoring with high precision without requiring system shutdown.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical bubble-decay method with a particle-based detection system. Instead of relying on pressure decay measurements that lack precision for ceramic membranes, the system uses marker particles whose presence or absence in the permeate provides direct, measurable evidence of membrane integrity, enabling both continuous operation and high-precision detection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If the challenge test is performed to verify membrane integrity, then the log removal value can be quantified, but the system must be shut down which reduces productivity and increases costs

Engineering Contradiction:
Improvemembrane integrity verificationVSAvoidwater filtered
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent enables continuous integrity testing by dosing marker particles into the operating system and monitoring their presence in the permeate stream. This eliminates the need to shut down the system for challenge tests, allowing the membrane filtration process to continue uninterrupted while still providing reliable verification of membrane integrity through the marker particle detection system.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The marker particles act as an intermediary that allows integrity verification without system shutdown. By tracking these particles through the membrane system, the method provides continuous reliability assessment while maintaining productive operation, resolving the contradiction between verification needs and productivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the bubble-decay method is used, then no system shutdown is required, but it cannot provide sufficient measurement precision for ceramic membranes with low porosity

Engineering Contradiction:
Improvetesting while runningVSAvoidprecision measurement for 3 µm breach
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces the pressure-based mechanical bubble-decay method with a particle tracking system. The marker particles provide a more sensitive and precise measurement mechanism that works effectively with low porosity ceramic membranes, maintaining ease of operation while dramatically improving measurement precision for detecting breaches as small as 3 µm.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the measurement parameter from pressure decay (bubble-decay method) to particle concentration in permeate. This parameter change enables precise detection of membrane breaches in ceramic membranes while maintaining continuous operation, as the particle concentration method is more sensitive to the low porosity characteristics of ceramic membranes.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables continuous membrane integrity testing without shutdowns, ensuring reliable filtration of contaminants like Cryptosporidium and bacteria by identifying breaches in ceramic membranes.

Implementation Method 1

A membrane may be used in water purification processes and/or fluid filtration processes, wherein a feed fluid may come into contact with a membrane, thereby forming a filtrate and a retentate

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 2

measuring a filtrate particle concentration of the filtered at least one marker in the filtrate to produce a filtrate concentration measurement; and measuring a feed particle concentration of the marker in the feed fluid to produce a feed concentration measurement

Methodology Applied
Scientific EffectParticle counting: Coulter Counter

Data Source

PatentEP3593109B1Method of marker based direct integrity testing of membranes
Publication Date: 2025.11.12 1934612 ONTARIO
  • EP3593109B1 patent drawingFigure 1
  • EP3593109B1 patent drawingFigure 2
  • EP3593109B1 patent drawingFigure 3

AI summary

The present disclosure relates, according to some embodiments, to methods of marker based direct integrity testing of at least one membrane comprising: (a) dosing a feed fluid of a loop with at least one marker comprising at least one challenge particle, the loop comprising: the feed fluid; a pump 220 comprising an outlet stream 222; a membrane module 218 comprising the at least one membrane and a membrane module outlet stream 210, wherein the membrane module 218 is in fluid communication with the outlet stream 222; a marker recycle stream 226 in fluid communication with the membrane module outlet stream 210 and the pump 220; and a means to measure particle concentrations; (b) circulating the feed fluid through the membrane module 218 at least once to produce a filtrate comprising a filtered at least one marker; (c) measuring a filtrate particle concentration of the filtered at least one filtered marker in the filtrate to produce a filtrate concentration measurement; and (d) calculating a log removal value from the filtrate concentration measurement and the feed concentration measurement; wherein the log removal value is less than about 3 μm.