I'm looking for a system to remove Iron and Manganese. I would normally consider a manganese greensand system, but this was proposed. Quite honestly it sort of seems too good to be true.
The raw water has 2 ppm iron 0.2 ppm manganese, pH of 6.8, 440 ppm TDS, 84 ppm sulfate, 18 ppm silica
Looking at the partial analysis you give actually would lean me towards using a water softener if: The hardness is 10+ grains hard. The added benefit would be appreciated. It can be sold as something with a payback rather than just a filter.
The problem with medias which count on oxidants to first oxidize the matter is just that, it is dependent on other actions to work properly. Dissolved oxygen levels, oxidant contact times and such....
Iron and manganese have added tendencies of being complex by things like organics. Take a mini softener and run the raw water through it, if the iron or manganese still remains, my whole post is a waste.
Other options are dissolved oxygen generators, (work really well for this) ozone, chemical feed sequesterants and the obvious other treatments.
Jim has some good advice here but I would be very careful.
A softener will do little if anything to reduce the sulfates. You would have to double bed it with carbon (Centaur) and get a vortex tank (at least) so that the carbon could be exchanged.
Birm is great for iron but not so hot for H2S or Manganese. It's also very important to perform a D.O. test to veryify the presence of dissolved oxygen.
Frankly, we try just about every other treatment path over the pot perm/manganese greensand treatment due to the very obvious problems:
clogged injectors, malfunctioning floats, incomplete rinsing causing red water in the home, and, of course, the inherent foul nature of Potassium Permanganate. It stains, it can over flow, homeowners always use too much or too little........the list of difficulties are legion.
There are many units offered by every OEM that specifically treat iron and manganese and sulfates by the induction of oxygen via the regenerant draw process, or just by the 'brine' cycle. Filox has been proven in the field if all other parameters are equal.
Finally the TDS should also be a concern. 440 is pushing the threshold of 500 which in the opinion of the USEPA classifies this water as near to being 'not desireable' for human consumption.
We use Filox media on a regular basis and it works very well if applied correctly. The parameters listed should not be an issue for the media as long as there is enough dissolved oxygen in the water and enough water to back wash the system. An ORP test should be performed to ensure there is enough dissolved oxygen or inject air to increase the ORP. The problem with air injection on iron is precipitated iron will clog piping prior to the filtration system and reduce flow rates that are required to backwash the system.
There are systems that contain air within the tank and avoid this problem. please contact me privately for further information on this system. The flow rates required for the Filox is 15-16 GPM per square foot of media. This is equivalent to approximately 7 to 8 GPM for a 1.5 cubic foot system. This is not likely from a 1/2 hp submersible pump depending on the depth and offset and should be approached with care.
The Filox media is also a great system for oxidizing arsenic from As(3) to As (5). If there is iron or manganese present there will also be an arsenic reduction of approximately 20 to 1. For example if you had .032 mg/L arsenic you could get total reduction through the Filox if you had .64 mg/L iron or higher.
I do agree the TDS is a little high and you have not listed the ions
that compose this totally. The recommended level for TDS is a secondary
parameter. The water may be objectionable in taste and a reverse
osmosis would address this issue. If the missing ions are hardness then
by all means a water softener is the answer to this water quality.
Filox has helped us solve many water quality issues BUT it must be applied correctly as with any filtration system. I am fan of ion exchange over oxidation due to the simplicity and overall maintenance costs, but oxidizing filters have their place in our diverse world. I do not recommend ordering any system without the consultation of a professional water treatment dealer.
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