In many cases water from surface and underground sources has high concentrations of salts of iron and manganese. Their presence is identified by unpleasant water odor and off-flavor. Water leaves specific ginger and grey-brown traces. Ferrous iron contained in underground source water quickly settles out into colloidal precipitate if exposed to air oxygen. This precipitate is a growth-supporting microenvironment for bacteria and microorganisms.
Deironer removes undesirable impurities from water making it suitable for use in drinking and process water supply systems. Filters are directly connected to water mains in order to ensure continuity of water treatment process.
Spc promvodochistka ltd provides several models of deironing units:
• Deironing units of y series with a capacity of 0.5–6.4 m3/h;
• Deironing units of y series with a capacity of 9.8–109.2 m3/h.
Treatment process is based on conversion of insoluble ferrous compounds into soluble ones. Rust or iron hydroxide colloidal flakes settle out.
Oxidizing process takes place on the surface of filter medium grains with high catalytic activity. Implementation of pre-aeration of incoming flow (for nonchemical cleaning) or use of dosing systems of secondary reagents (for chemical cleaning) enhances the treatment process.
in the course of operation water deironers are clogged step-by-step with insoluble substances of oxidation reaction. The process efficiency decreases. Flushing is used to restore deironers to working condition. Filter medium layers are flushed by back water flow thus washing off foreign impurities.
|Filtration mode||Flushing mode|
• Low wear rate of filter medium grains (no more than 2%) during operation;
• Filter medium regeneration by back flow excluding the use of additional reagents;
• Long-term (up to 5 years) operation period starting from filter medium charging to full replacement thereof;
• Possible common use with other water treatment systems;
• Iron removal in compliance with quality targets;
• Wide range of unit capacities;
• Process module reasonable price.
The main concept of nonchemical deironing is based on absence of secondary reagents since they are not added into the process chain. Pre-aeration of incoming flow greatly improves oxidation reaction behavior. In this case oxygen serves as a catalyst partially oxidizing dissolved iron.
At the initial stage of treatment process adsorption serves as a moving force. Oxidized iron compounds from water flow precipitate on the surface of filter medium.
Nonchemical treatment is the most efficient under the following conditions:
• Total iron content ≤ 10 mg/l;
• Ph≥ 6.8;
• Parasitic impurities content (sulfates ≤ 0.2 mg/l, ammonium compounds ≤ 0.1 mg/l).
Iron-containing compounds availability or high content (higher than 10 mg/l) of ferrous iron indicates the necessity for chemical cleaning utilization.
The following substances are used as reagents:
• Potassium permanganate;
• Sodium hypochlorite.
Regents are injected into flow of water being processed directly upstream of the filter with the help of a dispensing device.