Basic Pretreatment Equipment
Basic Pretreatment Equipment
A multi-media filter uses one or more filtering media. Under a certain pressure, water with high turbidity passes through a layer of granular or non-granular materials, effectively removing suspended impurities and clarifying the water. Common filter media include quartz sand, anthracite, manganese sand, etc. It is mainly used for turbidity removal, water softening, and pretreatment for pure water production. The effluent turbidity can reach below 3 NTU.
Product Advantages
1. Multi-media filters are widely used in water treatment processes. They can be used independently, but are mostly applied as pretreatment for advanced water treatment (ion exchange resin, electrodialysis, reverse osmosis).
2. Different filter media can be filled according to process requirements.
3. No large amount of chemicals or acid/alkali regeneration is required.
4. Low cost, low operating expense, simple operation and easy maintenance.
5. It can remove large suspended solids in water, thereby reducing the SDI value and meeting water quality requirements for advanced purification.
6. The filter media can be reused many times after backwashing, featuring a long service life.
Product Details
Working Principle of Multi-media Filter：
A typical multi-media filter (also known as mechanical filter) adopts layered anthracite, sand, fine garnet or other materials as the filter bed.
The top layer of the filter bed consists of the lightest and coarsest grade materials, while the heaviest and finest grade materials are placed at the bottom of the bed. Its principle is depth filtration: larger particles in the water are removed in the top layer, and smaller particles are removed in the deeper layers of the filter media. Thus, the water quality meets the standard after coarse filtration.
This equipment is pressure-type. Its working principle is as follows: when raw water flows from top to bottom through the filter media, suspended solids in the water are trapped on the surface of the filter layer due to adsorption and mechanical interception. As water flows deeper into the filter layer, the sand grains are arranged more densely, providing more chances for fine particles in the water to collide with the sand grains. Consequently, flocs and suspended solids adhere to the surface of sand grains, and impurities are retained inside the filter media layer, resulting in clarified water. The suspended solids content of the filtered effluent can be below 5 mg/L.
Application Fields of Multi-media Filter：
Multi-media filters are suitable for the pretreatment of systems such as reverse osmosis, electrodialysis, ion exchangers and ultrafiltration;raw water pre-filtration for power generation, chemical industry, papermaking, beverage production, etc.;decolorization and organic matter removal for chemical plant feed water;domestic water pretreatment;industrial water treatment;swimming pool water treatment;side stream filtration systems;turbidity and color reduction of surface water and groundwater;and wastewater treatment.
