GFO leaching PO4 back to water test....

JetCat USA · 08/11/2007, 08:50 AM

In This Thread I'm in the process of a few tests with PhosBan and just how much PO4 it can remove from a system. I've always used GFO for PO4 control and most claim it will not leach back to the water once exhausted. well i plan to test that once the media from the above mentioned thread has exhausted its self and someone messaged me that soaking the media in RO/DI water wouldn't be conclusive that the test needed to be done in salt water instead so the question is.........

the RO/DI is going to have roughly the same pH as the tank once the used GFO is added because it doesn't have any buffers to set its pH and the media will have residual water from the tank that should bring the RO/DI up to near the tank pH so low pH shouldn't be an issue (Habib brought up issues of lower pH with GFO a good while back in an unrelated thread).

can anyone see any reason why saltwater should be used instead???

AZDesertRat · 08/11/2007, 01:06 PM

This has been tested exhaustively by water treatment plants wordwide and it does not release things. GFO and GFH have been used in potable water for arsenic treatment for years. Thats the biggest reason the water treatment iindustry has gone away from aluminum based media since it is well documented it does release contaminants. GFO can be used for several different contaminants including arsenic and phosphates among others.

JetCat USA · 08/11/2007, 01:12 PM

Thanks AZ, saves the trouble of testing that out.

another quick question for you though, it was mentioned that you can bake GFO and renew it, I've never heard that before and can't find any info on it, any truth behind it??

AZDesertRat · 08/11/2007, 01:38 PM

I do not believe that to be true. You can cook carbon but not GFO to my knowledge. In the water industry we landfill it since even if it has been used for arsenic it is not considered a hazardous material.

bertoni · 08/11/2007, 02:10 PM

Baking GFO isn't going to help. Phosphate doesn't respond to such treatment.

Baking at extremely high temperatures will activate carbon, but the home oven isn't hot enough. It might be possible to extend the life of the carbon somewhat, though.

08/11/2007, 08:50 AM	#1
JetCat USA Moved On Join Date: Jun 2004 Posts: 2,847	GFO leaching PO4 back to water test.... In This Thread I'm in the process of a few tests with PhosBan and just how much PO4 it can remove from a system. I've always used GFO for PO4 control and most claim it will not leach back to the water once exhausted. well i plan to test that once the media from the above mentioned thread has exhausted its self and someone messaged me that soaking the media in RO/DI water wouldn't be conclusive that the test needed to be done in salt water instead so the question is......... the RO/DI is going to have roughly the same pH as the tank once the used GFO is added because it doesn't have any buffers to set its pH and the media will have residual water from the tank that should bring the RO/DI up to near the tank pH so low pH shouldn't be an issue (Habib brought up issues of lower pH with GFO a good while back in an unrelated thread). can anyone see any reason why saltwater should be used instead???

08/11/2007, 02:10 PM	#5
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	Baking GFO isn't going to help. Phosphate doesn't respond to such treatment. Baking at extremely high temperatures will activate carbon, but the home oven isn't hot enough. It might be possible to extend the life of the carbon somewhat, though. __________________ Jonathan Bertoni

08/11/2007, 01:06 PM	#2
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	This has been tested exhaustively by water treatment plants wordwide and it does not release things. GFO and GFH have been used in potable water for arsenic treatment for years. Thats the biggest reason the water treatment iindustry has gone away from aluminum based media since it is well documented it does release contaminants. GFO can be used for several different contaminants including arsenic and phosphates among others.

08/11/2007, 01:12 PM	#3
JetCat USA Moved On Join Date: Jun 2004 Posts: 2,847	Thanks AZ, saves the trouble of testing that out. another quick question for you though, it was mentioned that you can bake GFO and renew it, I've never heard that before and can't find any info on it, any truth behind it??

08/11/2007, 01:38 PM	#4
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	I do not believe that to be true. You can cook carbon but not GFO to my knowledge. In the water industry we landfill it since even if it has been used for arsenic it is not considered a hazardous material.