Gravel is used as a support layer in water treatment columns. Its role in the raw water filtration system is to retain dirt particles in the water and facilitate easier circulation of water within the system.
Quartz sand functions to retain fluffy precipitates, with high viscosity, difficult separation, and filtration. Precipitates of iron, manganese, for instance, are easily removed after water passes through this layer of sand. Particularly, quartz sand also forms a filtration membrane layer to assist in the arsenic adsorption process for arsenic-contaminated water sources.
Manganese Greensand is similar to Birm in its ability to remove contaminants. This filter material is often used in oxidation systems and injectors (air injection) to eliminate iron, manganese, and hydrogen sulfide (H2S). Manganese Greensand serves to reduce iron, balance the pH in water, and remove oil residues and organic matter present in household water.
ODM-2F or AC (AS Sorbent – Aluminosilicate) is a versatile filter material used in raw water filtration systems. ODM or AS pellets are Aluminosilicate materials with the main components being diatomite, zeolite, bentonite activated at high temperatures: SiO2 – 78%, MgO – 0.5%, Fe2O3 – 5.0%, Al2O3 – 7.0%... ODM/AC is considered a versatile material with roles including: pH stabilization; reducing nitrogen levels (nitrite, nitrate, ammonia); removing flocculants, phenolic compounds; iron and manganese reduction, hydrogen sulfite removal, and removal of heavy metals such as copper, zinc, chromium, nickel... through mechanisms like adsorption, ion exchange, catalysis.
Birm is a specialized water filter material used to remove dissolved iron, manganese, and hydrogen sulfite compounds in groundwater sources. Birm acts as a non-soluble catalyst to enhance the oxidation reactions of Fe2+ to Fe3+ in the form of iron hydroxide precipitate, which can be easily filtered out by backwashing. For Birm water filtration material to function, the water needs to have a neutral pH, which is a technical requirement to ensure the efficiency of the water filtration process.
