Such products are indeed useful for complexing transition metals thereby removing them from their environments.  However, I've not heard of anything useful regarding phosphorus.

You should be aware that the polymer you cited is not a di-carboxylic polymer, but rather a polymer of a carboxylate-functional monomer.  An example of the former would be poly-itaconic acid.  The significance lies in the efficiency of binding metals.  Some spatial/physical arrangements are more appropriate for a given metal than others. 

I suggest you contact the Rohm & Haas Company (now owned by Dow Chemical) for help in your quest.  They are pioneers in the use of polymeric acids for their ion-exchange properties, and have been a supplier to a wide range of industrial users for many decades. 

Hi Louis Belated thanks for your excellent reply to my question. You are quite right in your correction of my careless wording.  We have examined quite a range of both monomeric and di-carboylate polymers, including some of our own manufacture, as well as the Spersal 91 supplied by BWA for treating irrigation water; and Avail, supplied by Specialty Fertilizer Products, claimed to reduce P fixation. I totally agree with your comment on the lack of any direct evidence for the benefit of these polymers in this regard.

As mentioned, our research has concentrated very much on the amelioration of Al toxicity in acid soils (which is all New Zealand has). In this particular respect, we find very little differences in the effects of the different polymers tested. I guess this indicates the strength of the Al-carboxylate bond. We have decided to run with a monomeric polymer of fulvic acid, converted to the Na form, for now.

Now that I have finally finished putting up my rebuilt website (www.groupone.co.nz), I will contact Rohm & Haas as you suggest. Any further comments you have would be greatly appreciated. I have put our publications on our research into these polymers on my 'featured publication box'.

I would not limit your efforts to carboxylate functionality, since that is probably the weakest in turns of complex-formation with transition metals.  Far stronger are sulfonate, phosphate, and various nitrogen functionalities.  They also tend to provide more selectivity for some metals over others. 

But again, the ion-exchange world is quite experienced in removing such materials from water, and should be consulted for their considerable experience.  They should be able to provide you with abundant references. 

In addition to ion-exchange references, you may want to consult the whole inorganic chemistry fleld of complex-  and chelate-formation ligands.  But while you're at it, if your need is simple (e.g. remove aluminum), don't overlook simple inorganic remedies such as simple precipitation.  That could be simpler and less expensive, and not require regeneration of your ion-exchange columns. 

A useful (but quite old) reference is R. Kent Murmann's Inorganic Complex Compounds, a 1964 book published by Reinhold in the U.S., as part of the series titled Selected Topics in Modern Chemistry.  I mention this because it is in the style of older chemistry texts that were more descriptive than theoretical, and in addition contains abundant actual results, particularly in relative specificity for different metals.  it even takes the time to explain the difference between a complex and a compound, which is rare in today's literature. 

Of immediate interest, there is the suggestion that Al will exhibit similar relative strengths of complex formation to that of Zn.  (p. 43 in Murmann).  The absolute strength depends on the ligand, but the relative strengths tend to be maintained over a wide variety of metals and ligands.  In general, the strength of complex formation decreases with increasing basicity of the metal.  (p. 47 in Murmann). 

A more recent alternative would be the field of ionomers, which are polymers with high acid or base functionality, which are complexed with selected metals to achieve both a high degree of toughness, while being thermally reversible (and therefore processable).  The product Surlyn from DuPont was the first well-known application, and for a while was used for ballistic reinforcement of glass plates by using the Surlyn as an interlayer.  Adi Eisenberg of McGill University was a proficient writer on the topic of ionic polymers.  Ionomers in particular are sensitive to relative strengths of complex-formation, and thus have literature discussing the alternatives.