Drinking water treatment

Filtralite is suitable for use in many different potable water treatment processes, such as:

  • Biological treatment
  • Physical filtration
  • Pre-treatment for desalination

Advantages

Filtralite has a large pore volume and surface area that makes it an ideal media for treatment of drinking water. For biological treatment of water Filtralite is excellent for treating raw water containing ammonia, manganese, iron etc. For conventional, physical filtration processes, due to the unique porocity Filtralite enables longer filter-runs at higher filtration velocities. Replacing excisting media with Filtralite provides a return of investment in 2-3 years. Filtralite can be used as both a single and dual media filters.

Filtralite as mono and dual media filter

Filtration of water is the most traditional type of water treatment. Filtralite has the ideal properties to work as a good filter media in both mono and dual media filters for filtration of coagulated water. 

Compared to traditional filter media like sand and anthracite Filtralite has much higher porosity, which gives lower initial head loss, slower head loss build up and higher storage capacity. These advantages result in much longer filter runs between backwashes, which mean reduced energy and water consumption and higher water production, consequently giving reduced operating costs. 

By replacing sand with Filtralite in single media filters the operating time between backwashes can be extended by up to 500%. For dual media filters a change from sand and anthracite to the dual media Filtralite Mono-Multi, consisting of two different qualities of Filtralite, can provide up to 800 % longer filter runs. If only the top layer is replaced with Filtralite and the bottom layer of sand is kept the filter runs can be extended by about 150 %. For existing filters with low backwash velocities a change from sand to Filtralite will help keeping the filters clean, as Filtralite is much lighter than sand and therefore need lower backwash rates for cleaning.  

Filters with Filtralite can be operated within a large range of filtration rates. The filtration rate will always be dependent of the configuration of the filter and the treatment process. Existing Filtralite filters operate from about 2 m/h up to around 20 m/h.

Pre-treatment for desalination

For desalination plants it is of great importance of the operation of the entire plant that good pre-treatment of water takes place before the salt is removed. For reverse osmosis (RO) desalination plants, satisfactory pre-treatment is essential for avoiding membrane fouling. Membrane fouling may result in reduced water production and increased operational costs.

Advantages

Filtralite has excellent properties for use in pre-treatment filters in desalination plants in filters for filtration of coagulated water. Use of Filtralite will provide low SDI values, reduced danger for bio-fouling of the RO membranes and long filter runs between backwashes. The extra porosity of a Filtralite filter provides additional capacity to existing filters. As the head loss in a Filtralite filter is a lot less than in denser, traditional filter media, Filtralite provides higher filtration velocities and thus enables more efficent production of water.

Wastewater treatment

Filtralite is suitable for use in different effluent water treatment processes, both for municipal and industrial effluents, such as:

  • Biological treatment
  • Tertiary filtration
  • Odor treatment

Advantages

Filtralite's large pore volume and surface area make the material an ideal media for biological treatment of effluent water. Biofilm processes are excellent for treating water containing nitrogen, BOD etc. Years of experience have shown that Filtralite is a perfect media for wastewater plants. If extra strict outlet levels are required, tertiary filters are used. Filtralite has the ideal properties for use in mono- or multi media tertiary filters. The large porosity of the Filtralite grains gives low head loss and high storage capacity for suspended solids, resulting in long filter runs and low operational costs.

As well as in traditional effluent water treatment, Filtralite is used for odour treatment at sewage treatment works. The porosity of the material makes it excellent for use as biofilter for removal of hydrogen sulphate and other biodegradable odorous compounds.

On-site treatment

Filtralite P is a specialized product developed for on-site treatment of effluent water and removal of phosphorus from water at locations where access to municipal sewage is unavailable. 

Advantages

Filtralite P is a fine grained filter material with large surface area and a high capacity for phosphorus removal. Filtralite has developed this special product using clays and natural additives. The phosphorus is removed by both precipitation at high pH and physical-chemical attraction and bindings. The phosphorus compounds are captured, and thus removed from the water by the filter. In general, high P-removal is not obtained in natural treatment systems e.g. constructed wetlands and sand filters, with ordinary sand and gravel as filter media. However, by choosing a filter media that is tailored to provide large P-sorption capacity, a high degree of phosphorus removal is achieved. When the removal capacity is exhausted, the filter material can be replaced. The used material can be used as fertilizer or soil conditioner. Expanded clay materials are recommended as a horticulture improver and the addition of phosphorus makes it even more valuable as such.