Warden Biomedia

At Warden Biomedia, we design, manufacture and supply Random Biological Filter Media to improve aerobic treatment across the full range of applications - from the largest municipal sewage treatment plant down to a garden fishpond.

With the philosophy of increased surface area, the eco-friendly trickling filter and biological filter media are injection-moulded in recycled polypropylene with specific design features to increase the efficiency of the effluent treatment process.

In a choice of spherical and tube formats, to suit the application, the random filter media provide excellent ventilation to speed-up the aerobic reaction, and also have high voidage to prevent blocking (and the resulting slowing-down) of the wastewater treatment process that might occur.

With purpose-designed features, the media in the Warden Biomedia filter range are an excellent alternative to traditional mineral-based media and are ideal for improved performance in new wastewater treatment plants. In addition they are perfect for overcoming problems in established trickling filter beds. Polypropylene biological filter media of the relevant dimensions can replace all or part of the mineral-based media to improve system efficiency where it has become impaired by overloading.


The choice of spherical and tube formats, offers performance advantages not found in other random biological media.

  • Warden's Biomedia can be used as a direct replacement for gravel media, thus increasing both the degree of treatment and capacity of existing trickling filters
  • Our media greatly increase the contact time of the wastewater within the media, resulting in high efficiency with minimum recirculation
  • Due to continuous redistribution of water flow, the media offer a very high resistance to clogging
  • Settling effluent Total Suspended Solids (TSS) is much lower
  • Spherical shape designs feature triangular fins which increase the total surface area and encourage the formation of the biological films of bacteria, protozoa and fungi which will eat and biologically break down the organic content
  • The edges are serrated, this enables them to interlock in the filter bed giving excellent mechanical strength
  • They assist to distribute wastewater thoroughly, enhancing mixing and contact between wastewater and bacteria
  • They increase mean cell residence time thus increasing the efficiency of the wastewater treatment unit
  • Light weight, easy installation
  • The surface textures of Warden Biomedia offer a key which enables biomass or bacteria to adhere by special means, to lessen loss of media during installation procedures
  • Made with eco-friendly recycled polypropylene material
  • Compact, Low maintenance
  • Patented technologies
  • R&D driven


Warden Biomedia has numerous applications in wastewater treatment. The shape of the media has a significant influence on application and must be considered along specific surface area and void ratio. The surface area of media will be covered with biofilm. Attached growth bacteria will function cooperatively with suspended bacteria, thus its efficiency is higher when compared with other systems. Applications are as follows.

  • Upgrading existing gravel trickling filters
  • BOD Reduction in Trickling Filters
  • Complete Secondary Treatment
  • Trickling Filters/Solids Contact (TF/SC)
  • Roughing of pre-treatment
  • Nitrification
  • Denitrification
  • Organic removal
  • Detoxification

For random biological filter media - from the largest municipal sewage treatment plant down to a garden fishpond - Warden Biomedia has you covered, with the experience and knowledge to assist you in selecting of the right filter media for your application. Contact us today to see how we can work for you.

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