lanthanum chloride?

[abwalker]

Hi all,

After reading the BRS road trip thread, I was hoping those that went would elaborate on lanthanum chloride? The only other hobbyist I know that uses it (not a BRSer) was also inspired by the folks at Atlantis.

My understanding is that the chemical bonds (?) with phosphate and turns it into an insoluble (?) solid. But... then what?

Thanks!
Abby

 

[skyedolphan]

Im am sure Greg will chime in here but.
from my understanding Joe ( Atlantis) uses it as a drip in his protein skimmer where as the compound adheres to the phosphates and then they adhere to the skim/ foam from the protein skimmer ensuring quick removal.
I am also looking into this as getting the solution is not a problem but I am unsure as to how much/little would be needed to add without changing things to rapidly

 

[Greg Hiller]

I think that's pretty much it. Very inexpensive way of dropping phosphate. Apparently most supplements on the market that propose to remove phosphate are based on this chemical. They just cost 100X what they should. There are probably other concerns about this chemical. I believe there was a pretty good write up in The Reef Aquarium III (actually, there was a pretty good write up about just about anything dealing with reef aquaria you can think of in that book!). I'll read up when I get a chance. Joe Y. did say that if you add too much you can cause a prepitate of lanthanum carbonate which can sometime cloud acrylic.

 

[Jennifer]

I read the same thing and was also curious about Lanthanum Chloride.

Here is some info that I found about the chemical
http://www.americanelements.com/lacl.html
http://en.wikipedia.org/wiki/Lanthanum(III)_chloride
http://www.bluelinecorp.com/lacl3/index.htm

My research shows that this product is also used to lower phosphates in swimming pools.
My belief is that Lanthanum chloride can be purchased at a pool place. I am yet unsure as to what brand names it is sold under.

 

[reefkeeper2]

I have been working to come up with an idea of how to add lanthanum but keeping the process seperate from the display. I think I'm going to try it like this-
I am going to set up a seperate tank (an old 75 gal) like a refugium that is connected to the sump. Inside this tank I'll place a skimmer and perhaps something for mechanical filtration using carbon. Perhaps even my diatom filter. Once a day, the pump that supplies water to this tank will switch off for a few hours, isolating it from the rest of the system. This is when I would dose the lanthanum. The filters and skimmer would chug away, removing the precipitate and any residual lanthanum inside thre tank. After a few hours (time yet to be determined) the pump would go back on, and 75gal of phosphate free water recirculated to the system.
The idea is to keep the lanthanum out of the display and to remove the precipitate effectively. I need to find out if carbon can effectively remove excess lanthanum from water (I assume it will) and what effect ozone would have. The skimmer I use for ozone will be the one I use in that tank. I don't want to buy another piece of equipment!

 

[JeremyR]

I had some montipora bleaching when I added one of those products once a couple of times.. I'm not sure of the mechanism.. the phosphates weren't out of control when I did it either. After watching alot of customers who DID have bad po4 problems add those products, I can tell you that none of them told me their algae problems were solved and most of them ended up either going back to GFO or giving up.

 

[Greg Hiller]

Certainly driving phosphate super low is not a good idea. Might have been the problem with the Montipora, of course I don't really know. Just dumping in the hobby type products I think might be a problem unless you have good filtration that will actually remove the precipitate. Otherwise I'd imagine it might just release the phosphate in the future.

With anything like this you of course need to be super careful. An overdose due to miscalculation might be the end of your tank.

Joe Y. said that they used the pool supply type product.

 

[JeremyR]

I have the suspicion that alot of the people talking about dosing this to lower phosphate aren't doing so because they are observing an algae problem, but because they want to keep the testable level below a certain point, because XX book said and everyone says too.. sometimes if it ain't broke, don't fix it. I don't think it's going to accomplish nearly as much for people as they hope, people have been putting this stuff in their tanks for quite a while and I really haven't seen alot of long term benefit. It's a band-aid.

 

[skyedolphan]

Jeremy that is kinda where I am at.
My phosphates are atrocious I \If I remember correctly somewhere around 57ppm in July. I have used the foric oxide and it went up from June to July. A large part of me is "just leave it alone as your corals and animals are fine" but then another part keeps saying "ya but maybe they could be better than they are and you just dont know the difference"
between my constant Alk issues and Coraline problem I am not sure if I want to try to "fix" somehting else

 

[reefkeeper2]

Phosphates have only recently become a problem for me when I started feeding heavily for the non photosynthetic corals I have been keeping. The GFO is exhausted in two weeks or less. I also have had sporadic outbreaks of STN whenever I change the GFO, which has been an observed phenomenon by many. It's happened to me several times and I'm P.O.'d about it. I would love an alternative to GFO. I want a method that will keep phosphates low, not give my sps STN, and not cost me so much. That and a winning lottery ticket would be nice.

 

[JeremyR]

Well I think this stuff is more band-aid-y than the GFO.. the only way I would bother is the protein skimmer method.. the put it in the tank method hasn't really knocked my socks off. They say it is inert after precip, but sandbeds can be plenty low ph and I wonder if it really stays precipitated.

 

[reefkeeper2]

I agree, I would not just add it to the tank.

 

[Greg Hiller]

>around 57ppm in July.<

I'm sure you mean 0.57 ppm, but it still is Way high.

 

[Jennifer]

Check this article out.
This is a large PDF file. It appears to be for the australian government about the production of "Phos-lock". Lots of good info on Lanthanum.
Also it appears that "Phos-lock" is simply a mixture of Lanthanum and Bentonite clay.
http://www.phoslock.com.au/docs2/4 - NICNAS Public Report on Phoslock, July 2001.pdf

 

[Greg Hiller]

A few titbits from the above document:

>Clay minerals are very stable in the environment and once released the clay is expected to persist within aquatic sediments. The clay is expected to become “loaded” with lanthanum phosphate which is highly insoluble except at extremely high or low pH. The notifier indicated that PhoslockTM is stable in the pH region 5-11 which is applicable to the pH of most environmental waters likely to be treated with the new clay, and consequently re-release
of phosphorus and/or lanthanum is not expected.<

Sounds good so far.

>Since La3+ ions are toxic to some aquatic organisms (see Section 10), the potential release of free lanthanum from the clay to the water column would appear to be of most significance for the purposes of assessing environmental hazard associated with use of the new clay. In low ionic strength water, the lanthanum remains strongly bound to the clay silicate plates, but under saline conditions (high ionic strength) there is the possibility for a re-exchange of the bound La3+ for ambient Na+ (or Ca2+) ions. In reality, the conditions which would enable this to take place would not be realised in bodies of fresh water, although it remains a possibility in brackish water – eg. river estuaries. However, any La3+ released in this manner is not expected to remain free, since it is expected to become strongly associated with natural humic material in the water and sediments through interaction with carboxylate groups in humic and fulvic acid <

Sounds like in a marine environment the lanthanum phosphate might not be completely stable. Probably a good idea to make sure it is filtered out of the water. If it really does bind with 'humic' acids then I imagine that activated carbon would also remove it from water.

More, relates to how it interacts with living critters:

>Lanthanum competes with calcium in a large range of biomolecules and biomolecular processes. A review by Das et al., (1988) reported that La3+ reacts in vitro with various tissue components, eg proteins, enzymes and phosphates. By displacing and replacing calcium ions in certain selected cell systems, La3+ inhibits the significant role of calcium in the various cellular processes. For example, La3+ inhibits the calcium pump of red blood cells and, in animal studies, La3+ has been shown to inhibit muscle activity by blocking calcium-activated enzymes.<

 

[Jennifer]

Sounds like in a marine environment the lanthanum phosphate might not be completely stable. Probably a good idea to make sure it is filtered out of the water. If it really does bind with 'humic' acids then I imagine that activated carbon would also remove it from water.

I was thinking the same thing.

a few more excerpts from the article.

Dissolved lanthanum is very toxic to species of daphnia in both acute and chronic tests. It may also be toxic to other species, although no definitive tests results with these organisms were available for this assessment. However, the field monitoring data available from one short trial in the Canning River has shown no adverse effects on aquatic biota except for an apparent avoidance of areas covered by the clay by gobies (bottom dwelling fish), although it is not certain this effect is directly attributable to application of the clay. Some water birds living and nesting in the riparian verges of the river were disturbed through activities associated with clay application. This will need to be prevented by more careful application techniques. Nevertheless, more extensive field monitoring of the indigenous biota at clay application locations would have been preferred. It is understood additional data will be acquired during future field trials.

Interesting ......

Public health
The notified chemical is not available for sale to the public, however its use as a water treatment chemical may lead to widespread public exposure. This exposure will be limited if waterways are closed during treatment processes. Contamination of drinking water with the notified substance would also lead to widespread public exposure. No drinking water guidelines for lanthanum levels have been established at this time.

and my favorite part.

In treating waterways with this chemical, dissociation of the lanthanum chloride from the bentonite should be avoided as far as possible. Contamination of drinking water with the notified chemical, or with dissociated lanthanum should be avoided, and the public should be excluded from areas under treatment until there has been sufficient opportunity for the chemical to disperse.

What do you guys think about adding Lanthanum to your tanks? I may just stick with GFO. But again I am not a chemist so I may be reading too much into this 1 report.

 

[JeremyR]

Band-aid at best. Hehe.

 

[Greg Hiller]

Looks like Paul dredged up this thread on RC:

http://www.reefcentral.com/forums/showthread.php?threadid=1357466

In that thread this article is referenced:

http://www.phoslock.com.au/Alum and Phoslock Comparison.pdf

Suggesting lanthanum chloride may work better at lower pH's. I'm starting to think about pumping it very slowly into the effluent from my calcium reactor and then running the resulting liquid after being held for a short time though a fine particular filter.

 

[Greg Hiller]

Wow, a lot of good stuff in this thread:

http://aqualitysymposium.org/phpBB2/viewtopic.php?t=6

 

[Jennifer]

Sounds like in a marine environment the lanthanum phosphate might not be completely stable. Probably a good idea to make sure it is filtered out of the water. If it really does bind with 'humic' acids then I imagine that activated carbon would also remoMore, relates to how it interacts with living critters:

In reading that article you just posted. It looks like Lanthanum does bind with humic acid but also it appears that humic acid prevents the Lanthanum from binding with Phospphates. Thus making the Lanthanum or "Phoslock" less effective at removing phosphates.

am I reading that right?
What would remove humic acid before going through "Phoslock"?