Membrane Efficiency

Biofilm and microbial growth can reduce the performance of membrane-based water purification systems, increase cleaning requirements, and shorten the life of critical system components. High purity chlorine dioxide is one of the most effective biocides for controlling microorganisms in membrane systems.

CDG Environmental’s Solution 3000 is a ready-to-use chlorine dioxide solution that helps remove and control slime that can block filter cartridges, membranes, pipes, and other components.

How Chlorine Dioxide Supports Membrane Performance

When properly applied at low doses, high purity chlorine dioxide can help control microbial growth without damaging membranes. Solution 3000 is effective across a wide pH range and can be used for precise intermittent or variable dosing.

Key benefits include:

• Controls slime that blocks filter cartridges and membranes
• Helps remove biofilm and prevent regrowth
• Quickly kills bacteria, viruses, algae, and protozoans at very low doses
• Works across a wide pH range of 6 to 9
• Remains effective where chlorine becomes less effective, especially above pH 7.5
• Provides very low corrosivity
• Can be dosed continuously or intermittently
• Supports reliable operation with low capital and maintenance requirements

Why Biofilm Is A Problem In Membrane Systems

Biofilm is one of the most common challenges in membrane-based water purification. Bacteria and other microorganisms produce a polysaccharide layer that creates a slimy coating on membranes, filters, pipes, and other system components. This layer protects and supports the growth of microorganisms. Biofilm can be especially problematic in water with high nutrient levels, such as wastewater effluent streams.

Biofilm can:

• Restrict water flow through membranes and filters
• Reduce membrane system efficiency
• Increase the need for off-line cleaning
• Cause production shutdowns
• Lead to costly replacement of filter or membrane elements
• Regrow quickly after cleaning if it is not fully removed

Limitations Of Traditional Cleaning Methods

Chlorine, hypochlorite, and related chemicals are often not effective for controlling biofilm in membrane systems. These chemicals can also damage membranes.

Some disinfectants are only partially effective because they cannot penetrate the polysaccharide matrix that protects the microorganisms inside biofilm. When biofilm compromises membrane performance, the system may need to be shut down for mechanical cleaning and disinfection.

Off-line cleaning can be costly because it may require:

• System shutdown and lost production
• A secondary membrane system to maintain output
• Mechanical cleaning that can damage expensive membranes
• Repeated cleaning cycles as biofilm returns

Because off-line disinfection may not remove all biofilm, remaining microorganisms can re-seed the system and grow back more quickly after each cleaning.

High Purity Chlorine Dioxide For Biofilm Control

Published test results demonstrate that pure chlorine dioxide supplied in a ready-to-use aqueous solution can remove bio-fouling and help prevent regrowth on Thin Film Composite (TFC) membranes and filters in reverse osmosis and ultra-filtration systems, without damaging membranes.

Previous reports of membrane damage from chlorine dioxide are believed to be related to impurities, such as chlorine or chlorous acid, in chlorine dioxide produced at the point of use. These impurities are not present in CDG Environmental products.

When properly applied, very low doses of chlorine dioxide can help control biofouling in:

• Feedwater passages
• Cartridge filters
• Both sides of the membrane
• Permeate water
• Reject water

Solution 3000 Ready-To-Use Chlorine Dioxide

Solution 3000 is designed to make chlorine dioxide treatment simple and controllable for membrane system applications.

Advantages include:

• Ready-to-use chlorine dioxide
• Minimal chemical exposure for operators
• No chemical mixing required
• Easy control for precise dosing
• Suitable for intermittent or variable dosing
• Low capital requirements
• Low maintenance requirements
• Reliable operation

Contact Us

To learn more about membrane efficiency and chlorine dioxide treatment for membrane systems, contact CDG today.