FILTER MEDIA
A water multimedia filter is used to reduce the level of SDI (Silt Density Index), TSS (Total Suspended Solids) in the incoming feed water. Suspended solids consist of small particles such as silt, clay, grit, organic matter, algae and other microorganisms. Incoming feed water that is high in suspended solids can cause a high pressure drop and reduce the effectiveness of downstream filtration equipment such as membranes, reverse osmosis membranes, electrode ionization EDI, UV sterilizer and ion exchange beds, if the multimedia filtration is not used as a pretreatment.
Water tech has several of types of filter media which can be used in various industrial applications.
GRAVEL,GRADUATED SAND / ANTHRACITE
- Sand filtration is a frequently used very robust method to remove suspended solids from water.
- Applications for sand filtration:
- Preparation of cooling water / Treatment of waste water.
- Production of drinking water / Filtration in swimming pools.
- Pre filtration for membrane systems / Filtration of grey or surface water / Removal of iron.
- A sand filter has a dirt holding capacity of 3 to 6 kg TSS / m2 of sand surface.
ACTIVATED CARBON
- is used to purify liquids and gases in a variety of applications, including municipal drinking water, food and beverage processing, odor removal, industrial pollution control.
- Activated carbon is produced from carbonaceous source materials, such as coconuts, nutshells, coal, peat and wood.
- The primary raw material used for activated carbon is any organic material with a high carbon content.
- Adsorption is a process where a solid is used for removing a soluble substance from the water. In this process active carbon is the solid. Activated carbon is produced specifically so as to achieve a very big internal surface (between 500 – 1500 m2/g).
- Activated carbon filters depending on the type of water, suspended solids concentration, oil and grease, COD, BOD and pesticides contents.
IRON REMOVAL PLANTS
- Can be based on different filtration media, depending on the iron and manganese concentration, the oxygen level, CO2 content and hardness of the water.
- Plant principle:
- First, air is injected in order to oxidize the iron. The oxidized iron will then precipitate on a sand filter. An MnO2 layer in the sand bed will catalyze the oxidation of residual iron. Backwash will be done by water and by air. More on.
MANGANESE GREEN SAND
- Manganese Green sand is formulated from a glauconite greensand which is capable of reducing iron, manganese and hydrogen sulfide from water through oxidation and filtration.
- Soluble iron and manganese are oxidized and precipitated by contact with higher oxides of manganese on the greensand granules.
- The hydrogen sulfide is reduced by oxidation to an insoluble sulfur precipitate.