Focal Point Biofiltration Media System

Bioswale DesignTreatment Unit Processes Rate DescriptionIMPORTANT PARTICLECAPTURING MECHANISMSSedimentation Fast Particles settle on surface of media by gravity.Physical straining (filtering) Fast Larger particles cannot pass the media pores.Inertial Impaction Fast Particles adhere to filter media as they collide.Interception Fast Particles in close proximity attach to one another.adsorption Fast Accumulation of material onto filter media surface.absorptionIncorporation of material into the filter media.Bacterial adsorption Fast Particles stick or adhere to bacteria cell wall slime.Plant adsorption Fast Particles adhere on plant roots.Chemical Biological CapturingMechanisms[Important in P, N and heavy metal removal]Precipitation Fast –MediumFor example P may react with AL or Fe to forminsoluble compounds.Cation & Anion ExchangeCompounds with exchangeable positive andnegative ions are bond soil particles and organicmaterial in the mediaPlant & Microbe ion exchange Fast –mediumPlant roots, mycelium hairs and microbe cell wallsall have the ability to actively exchange ions withnutrients such as P, N and heavy metalsPhysical Adsorption Fast Electrostatic forces, electrokinetic forces andVander Waals forcesVolatilization Medium Volatile compounds are removed from the mediathrough evaporation or actively removed throughtranspiration.Plant / MicrobialSequestration /transformation / growthSlowMediated decay of organic material, uptake ofnutrients and transformations of complexcompounds for growth and energy.