In filtration, the more pores a treatment medium has, the more effective it is. Zeolite for water filtration has a great many pores, so it not only captures particles between its grains but also retains them on the surface of the medium. This is partly due to the cation exchange capacity of zeolite minerals.
Zeolite takes up positive ions from the water, such as dissolved metals, sodium and ammonium, and exchanges them for ions already held at the medium’s exchange sites.
Thanks to its high pore density, zeolite has a large effective surface area, so it can capture high concentrations of contaminants before backwashing is needed. The medium can also remove some particles by adsorption, in which particles actively attach to the surface of the medium rather than being passively trapped between the grains.
General uses of zeolite and the industries it serves
Water treatment
- Removal of turbidity particles down to three to five microns
- Removal of heavy metal cations, certain hydrocarbons and other contaminants
- Direct replacement for sand in filtration systems, with 2.8 times the sediment loading capacity
Wastewater treatment and pollution control
- Ammonia removal from municipal and industrial wastewater
- Improved biological activity, lower nutrient levels, and reduced sludge volume and odours
- Reduced ammonia and BOD levels in ion exchange columns or bed effluent, with the ability to be backwashed and regenerated
- Recovery of ammonia for use as fertiliser, increasing treatment works capacity and extending its life cycle
Radioactive water treatment
- Treatment of caesium and strontium in cooling processes and nuclear waste
- Site remediation and decontamination
Aquaculture and fisheries
- Ammonia control
- Use as a biofiltration medium
Agriculture
- Animal waste treatment and odour control
- Water clarification and disinfection
- Lower ammonia levels in ponds and water tanks
- Reuse of spent media as a soil conditioner
Horticulture (nurseries and greenhouses)
- Turbidity reduction
- Water clarification and a physical barrier for bacteria control
- Reclamation and revegetation (spent media can be reused in potting soil and similar)
The most significant benefits of zeolite for water filtration are seen in drinking water treatment systems.
Affinity for ammonia and heavy metals
Zeolites, especially clinoptilolite, are well known for their ability to remove ammonia and heavy metals from water. Their structure of porous channels and cavities provides an excellent surface for adsorption, making them highly effective in water treatment.
Zeolites are also stable and relatively inert materials, suitable for long-term water treatment without significant degradation. Another advantage is their ability to selectively retain certain contaminants while letting other ions pass.
Overall, zeolite for water filtration can effectively remove ammonia and heavy metals, helping to make drinking water safer for communities.
Water softening
Hardness minerals such as calcium and magnesium can cause problems in distribution pipework if their concentrations are high enough. At a certain point their concentration reaches supersaturation and they start to precipitate out of solution.
In homes this leads to scale build-up and lower flow through pipes and taps. Zeolite can exchange calcium and magnesium ions in the water, acting as a water softener when it is regenerated with sodium or potassium brine.
Iron removal
Have you ever turned on a tap and seen brown water? Then you may have an iron problem. It does not take much iron to change the colour of water, and higher iron levels can affect water quality and health.
Iron therefore needs to be reduced in drinking water. Sodium zeolite can help reduce iron levels to some extent thanks to its adsorption and ion exchange properties.
Key points
For water treatment solutions for your home or business, see our zeolite filtration media or contact KEIKEN.
