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fluoride removal
- Thread starter jporter26
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We also have a similar problem with fluoride, so I'd like to tag onto this thread as it starts.
The application is for a mine in the Western US. The groundwater is removed from the mine pit to keep it dry - then the groundwater is discharged in another location after it meets local limits. The flow rate is 2,000 GPM.
There is 3-4 ppm fluoride in the groundwater that has to be reduced to below 2 ppm. There is already a treatment system in place for arsenic removal. Ferric chloride and anionic polymer is added via in-line injection to reduce arsenic. The resulting solids settle out into a large contained pond prior to discharge. The pH of the groundwater is 7 - 8. What options might we consider to keep the costs down and still meet discharge limits for fluoride?
Thanks.
The application is for a mine in the Western US. The groundwater is removed from the mine pit to keep it dry - then the groundwater is discharged in another location after it meets local limits. The flow rate is 2,000 GPM.
There is 3-4 ppm fluoride in the groundwater that has to be reduced to below 2 ppm. There is already a treatment system in place for arsenic removal. Ferric chloride and anionic polymer is added via in-line injection to reduce arsenic. The resulting solids settle out into a large contained pond prior to discharge. The pH of the groundwater is 7 - 8. What options might we consider to keep the costs down and still meet discharge limits for fluoride?
Thanks.
Good Evening - though the fluoride counts differ - we just finished demonstration on fluoride reduction on phosphate mine water - down and dirty test - in 20-minutes, took fluoride down 2300ppm, sulfate 2800ppm, phosphate 500ppm - in pH of 1.8.
Same reduction rates occur at higher pH when electroytic processes applied. We expect to run further tests alter in Janurary to determine how fast and just how low we can go - trying for "0". We are running the test for AWS Consultants in Florida - so you should contact them direct for further information. contact party is Art Suma - telephone is 813-655-9406. Email is DCHPPAGE@aol.com (have to use capitol letters on the email).
Regards -
Dave Orlebeke/Aquatic Technologies
Same reduction rates occur at higher pH when electroytic processes applied. We expect to run further tests alter in Janurary to determine how fast and just how low we can go - trying for "0". We are running the test for AWS Consultants in Florida - so you should contact them direct for further information. contact party is Art Suma - telephone is 813-655-9406. Email is DCHPPAGE@aol.com (have to use capitol letters on the email).
Regards -
Dave Orlebeke/Aquatic Technologies
Ok all:
we have been working on a system with 10 ppm of Fl 100 ppb of AS PH raw at 8 - 8.5 and average temp of 112 F and a flow rate of 10GPM:
we are using Actavated Alumina.
my personal opion as that although it is working it is labor hevaythe steps are in this order:
1. ad acid to lower the PH to 6.0 (5.5-6.5)
2. run water through the AA bed alowing for a contact time
of about 5 min / per gal / per cubic ft of medea
3. check PH on outlet for minimum of 7.0 and monitor FL at
this point.
we have found that our plant does not work the same as the plant 5 miles down the road. so you will need an operator that can spent the time "tweeking" the system we have found that our plant optimises when the outlet PH is at 8.0 .. also, you will have a fair amount of backwash water to deel with we are using evap ponds here.
you might also look at using RO the initial cost looks more but the time and additional outlay for A.A. add up fast!!! (chem injector pumps, safty shower, chemicals, operator time, *there is not any training I have found so it is all OJT to lern how to make it work* and the list goes on and on).
by the time we figured out that RO would have been more cost effective we were committed to the A.A. system. (over 40K commited for a customer base of 18, RO would have cost us about 25K - 30K for the flow rate we need and allowed for the first year of O&M.)
good luck and let us know what you do and how it works out for you.
h2oman
we have been working on a system with 10 ppm of Fl 100 ppb of AS PH raw at 8 - 8.5 and average temp of 112 F and a flow rate of 10GPM:
we are using Actavated Alumina.
my personal opion as that although it is working it is labor hevaythe steps are in this order:
1. ad acid to lower the PH to 6.0 (5.5-6.5)
2. run water through the AA bed alowing for a contact time
of about 5 min / per gal / per cubic ft of medea
3. check PH on outlet for minimum of 7.0 and monitor FL at
this point.
we have found that our plant does not work the same as the plant 5 miles down the road. so you will need an operator that can spent the time "tweeking" the system we have found that our plant optimises when the outlet PH is at 8.0 .. also, you will have a fair amount of backwash water to deel with we are using evap ponds here.
you might also look at using RO the initial cost looks more but the time and additional outlay for A.A. add up fast!!! (chem injector pumps, safty shower, chemicals, operator time, *there is not any training I have found so it is all OJT to lern how to make it work* and the list goes on and on).
by the time we figured out that RO would have been more cost effective we were committed to the A.A. system. (over 40K commited for a customer base of 18, RO would have cost us about 25K - 30K for the flow rate we need and allowed for the first year of O&M.)
good luck and let us know what you do and how it works out for you.
h2oman
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