Biofouling Prevention with KilBac: everything you need to know

Protecting water-based systems from biofouling

 

Biofouling - the undesirable accumulation of microorganisms such as bacteria, algae, and fungi on filter media - poses a persistent challenge for aqueous systems across a host of industries.

This phenomenon is primarily driven by the presence of organic matter and nutrients in water, which facilitate the rapid growth and colonisation of microbial communities on filter surfaces and within porous matrices.

The consequences of biofouling are far-reaching: it leads to reduced product quality, contamination risks, and significant operational inefficiencies. Increased differential pressure across filters, more frequent filter replacements, and unplanned downtime all contribute to higher maintenance costs and lost revenue.

Notably, sectors such as water treatment, building services , oil & gas and power generation have reported that biofouling not only accelerates filter clogging but also forces costly disruptions and compromises product integrity. These widespread issues underscore the urgent need for innovative solutions capable of preventing microbial build-up and safeguarding both process reliability and product quality.

Biofoul Kilbac

Where the challenge begins

From HVAC loops in commercial buildings to ultrapure water in microelectronics, biofouling - the build-up of bacteria, algae, fungi, and other biological material - can quietly compromise system performance, increase maintenance costs, and shorten equipment life.

In countless industrial and commercial environments, water is essential, but it’s rarely clean for long. Wherever water is stored, recirculated, or left to stagnate, microbial contamination becomes a risk.

Here are just some of the water-based applications where biofouling can be a persistent and costly problem:

  • Building Services
  • Pharmaceutical and Biotechnology
  • Oil and Gas
  • Utilities and General Industry
  • Microelectronics
  • Automotive and Metalworking
  • Power Generation
  • Environmental and Wastewater
KilBac Infographic

 

 

 

 

The Problem - Biofouling in Filtration Systems

Depth filters are used extensively in these aqueous systems to remove particulate contamination that can compromise the efficiency of process equipment or blind membrane purifications systems. These depth filters, whilst removing particulate will also be removing the bacteria that has colonised on the particulate. Over time the bacteria will multiply within the structure of the filter media leading to accelerated blockage and biofilm build up on the filter itself.

This leads to multiple problems

  • Increased differential pressure across the filter
    • Decreased filter lifetime
    • Increased cost of filter consumables
  • High concentrations of bacterial sloughing off the filter as it growths through the filter media to the downstream side of the filter
  • Physical blockage of filters

In closed-loop systems, biofilms form when bacteria, debris, and corrosion products attach to pipe surfaces. These biofilms act as protective layers for microbes, allowing them to multiply and spread. Over time, this leads to reduced thermal efficiency, corrosion, and even health risks such as Legionella.

So the question is - how do we prevent the growth of microbial contamination on the filter? The answer - an antimicrobial filter media in the form of Amazon Filter' KilBac.

 

Infograph Kilbac

The Solution - KilBac® Antimicrobial Filtration

KilBac is Amazon Filters’ advanced antimicrobial filtration technology, engineered to actively prevent biofouling on the filter itself and within the system.

What it is:

KilBac® filters are available in SupaSpun, SupaGard, and Contour formats. They incorporate meltblown fibres embedded with antimicrobial agents—silver (Ag), zinc (Zn), and copper (Cu) - carried by micron-sized zeolite particles.

 

What It Does:

  • Kills bacteria and algae on contact
  • Prevents biofilm formation on the filter surface
  • Reduces microbial load in recirculating systems
  • Extends filter life and protects downstream equipment

 

How It Works:

Unlike nano-silver technologies, KilBac’s micron-sized carriers ensure that antimicrobial ions are exposed to the water stream. This allows for:

  • Consistent antimicrobial action
  • No leaching into process water
  • Compatibility with both single-pass and recirculating systems

 

 


 

 

 

 

Proven Performance

KilBac® isn’t just a lab innovation—it’s been tested and validated in real-world conditions.

 

Case Study: SupaGard KilBac in Marine Water Tanks

A leading marine technology company faced persistent bacterial contamination in their on-site water test tanks. Their existing system relied solely on 20 micron sand-bed filtration which required:

  • Constant chlorine dosing
  • Frequent monitoring
  • Regular downtime due to unusable tanks

After adding KilBac SupaGard's (1 micron), they saw immediate benefits:

  • Cleaner tanks – water remained visibly clear with no green discolouration
  • Reduced chlorine usage by 90% – less chemical dosing and monitoring
  • Less downtime – bacterial contamination brought under control
  • Improved reliability – staff could focus on other priorities

View the photo of before and after below, or read the full case study here.

Kilbac Case study split image

 

Recirculating System Trials

In closed-loop tests using E. coli, SupaSpun KilBac filters showed:

  • No increase in differential pressure after two weeks
  • Microbial contamination reduced from thousands to hundreds of CFU/ml
    Standard filters, by contrast, doubled in pressure and showed much higher contamination.

KILBAC_CHART NEW-1

 

50-Day Recirculation Trial  

KilBac vs Unmodified PP - Test simulating real-world conditions, showed:

  • 1 micron KilBac, 1 micron SupaSpun, and no filter were tested in an open tank system.
  • No bacteria were added; the system was shut down overnight and on weekends.
  • KilBac maintained stable bacterial levels throughout the test.
  • Unmodified PP and no-filter setups showed bacterial growth.

This trial confirmed KilBac’s ability to suppress microbial growth even in challenging, uncontrolled environments.

KilBac recirculation test results

 

Algae Control

KilBac filters using Ag/Cu combinations were tested against Chlorella sp. algae. Results showed:

  • Superior algae suppression compared to nano-silver and untreated polypropylene
  • Reduced optical density in growth media, indicating lower biomass accumulation.

 

Efficiency on Bacteria

Standard ASTM testing has been conducted on the SupaSpun KilBac® to demonstrate the antimicrobial effects on:

  • S.aureus
  • E.coli
  • P.aeruginosa 
  • B.Subtilis

Test data for P.aeruginosa tested to ASTM 2149 is provided in table below:

KilBac test table 2

 

Product Formats

KilBac® is available across three core filter ranges to suit different system needs:

SupaSpun KilBac®

  • Absolute rated meltblown depth filters
  • Ideal for precision applications
  • Available in 1–20 µm ratings
  • Designed for consistent and reliable performance

SupaGard KilBac®

  • Nominal rated meltblown depth filters
  • Suitable for general industrial use
  • Available in 0.5–20 µm ratings
  • Features moulded end caps and rigid support cage

Contour KilBac®

  • Large diameter, coreless format
  • Designed for high-flow installations
  • Minimises plastic waste
  • Available in 0.5–100 µm ratings

Each format is available in two antimicrobial grades:

  • Grade A (Ag/Cu) – Targets algae
  • Grade B (Ag/Zn) – Targets bacteria

Website-09_Kilbac Holding

 

Explore KilBac® filter formats tailored to your system. Request a sample to trial in your application. Speak to our technical team for guidance on integration. Contact us today to find out how KilBac® can improve your filtration strategy and reduce biofouling risk across your operations.

 

 

 

 

KilBac FAQs

Does the antimicrobial effect continue to work downstream of the filter?

The antimicrobial function of KilBac is primarily designed to prevent biofouling on the filter fibres themselves. In single-pass systems, the concentration of silver ions released is too low to have any meaningful antimicrobial effect on the water downstream. However, in recirculating systems, depending on the volume of water, there may be a residual level of silver that helps suppress microbial growth. This effect has been observed in internal recirculation tests.

When should the filter be changed?

Filters should be replaced when the maximum differential pressure (dp) for the filtration system has been reached. 

How long does the antimicrobial effect last?

The longevity of the antimicrobial effect depends on the operating conditions. Elevated process temperatures and saltwater environments tend to shorten the active lifetime of the antimicrobial agents. In some applications, such as ice and drinking water dispensers in North America, the antimicrobial effect has been shown to last up to one year. However, the actual duration will vary depending on the specific application and system setup.

Does KilBac work on microorganisms other than those listed in the datasheet?

In theory, yes. The antimicrobial agents used in KilBac filters are effective against a broad range of microorganisms. However, efficacy should be confirmed for each specific application. A simple way to test this is by placing a section of KilBac filter media on an agar plate inoculated with the target bacteria to observe whether growth is inhibited.

Can KilBac filters be retrofitted into existing housings or systems?

Yes, KilBac filters are designed to be compatible with standard filter housings. This allows for easy integration into existing systems without the need for major equipment changes, making them a practical upgrade for facilities looking to improve biofouling control.

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