The most efficient means of treating water that has a high concentration of iron and/or hydrogen sulphide (rotten egg smell) is the Chlorination / De-chlorination system.
Liquid chlorine is injected into the water supply line exiting the water pump, as it travels to a contact tank.
For this process to work correctly, the chlorine has to be in contact with the water for a minimum length of time of between 10 and 12 minutes. This is achieved with the use of a 120 gallon contact tank.
The chlorine oxidizes the liquid iron and/or hydrogen sulphide converting it from a liquid to a solid. The impurities are seperated from the water and settle at the bottom of the contact tank; these impurities are flushed out a drain at the bottom of the tank on a monthly basis.
The clean water exits the contact tank from the top, where it flows to a charcoal filter, which removes the chlorine from the water, as well as any suspended particles that may not yet have settled at the bottom of the tank.
An automatic Fleck valve controls the backwashing of the carbon filter to ensure the carbon remains clean, and extends its life.
After the carbon filter, the water flows to a water softener which removes the Calcium, Magnesium and inorganic minerals,
The biggest advantage of this system over other systems such as Manganese Greensand, Birm, KDF, etc. is that NO filter is used to remove the iron.
In other systems, the iron is removed as it flows through the filter. In most cases, strong oxidation chemicals such as Potassium Permanganate are required to charge the filter media in order for the process to work.
These filters can only filter a certain volume of water before they HAVE to be backwashed and regenerated with the required chemicals. Should a large volume of water be consumed, the occupants would run out of filtered water until the filter regenerates.
The control valve on the filter has an injector to control the dosage of regenerant. This injector has to be cleaned on a regular basis to avoid blockage. Should the injector get blocked, the filter will not remove the iron or hydrogen sulphide.
The filter media inside these filters are typically of a dense nature, thereby restricting the water flow rate.
The filter media gets fouled and clogged .