Iron & Mn Removal
Iron & Mn Removal
(OP)
I have a small non-community potable water system (5 gpm well yield for small demand)that requires iron and manganese removal (0.6 mg/l each, approximately).
System design already uses filtration, then chlorine injection to atmospheric tanks for contact time, then booster pumps to distribution. I'm wondering what is the most cost-effective treatment process to add to the system, considering the following options:
greensand filter
aeration (pumped air or aeration trays - though I've heard it can be slow?)
water softener
proprietary oxidizing filters
sequestration by polyphosphates
Are there other solutions I've not come across? I have raw water test data if there are parameters of concern for any of these treatment processes.
Thanks for any information.
System design already uses filtration, then chlorine injection to atmospheric tanks for contact time, then booster pumps to distribution. I'm wondering what is the most cost-effective treatment process to add to the system, considering the following options:
greensand filter
aeration (pumped air or aeration trays - though I've heard it can be slow?)
water softener
proprietary oxidizing filters
sequestration by polyphosphates
Are there other solutions I've not come across? I have raw water test data if there are parameters of concern for any of these treatment processes.
Thanks for any information.





RE: Iron & Mn Removal
Gary Schreiber, CWS VI
The Purolite Co.
RE: Iron & Mn Removal
The aeration system is difficult to work in a small system and will not work with low pH.
Sequestration by polyphosphates will not do anything for you.
RE: Iron & Mn Removal
Having said that, I would continue to use filtration. However, I would suggest switching the location of your chlorine injection so that it's injected prior to the filters. Inject enough chlorine at that point so that your 2mg/L is available as residual after the filter. Chlorine injection will act as a particularly suitable oxidation process at these iron levels and will greatly increase the amount of iron removed in the filter. For that flow rate, I'd recommend a pressurized filter vessel at least 14 inches in diameter.