M = Metal Ion or Complex


Octolig® is an immobilized ligand that is chemically bound to a silane that is chemically bound to silica gel. The ligand chelates heavy metals as waste water is passed through the column. Octolig® acts as a “host” to the heavy metals. The heavy metals are retained on the Octolig® in a one-molecule-thick layer on the surface of the silica gel as a result of chelation. Since all chelation reactions take place on the surface, contact times between the heavy metals and the Octolig® are not critical.

Octolig® is produced from a pH responsive ligand that retains heavy metals from solutions in a pH range (between pH of 2 to 10) and releases the heavy metals at high concentrations at a pH lower than 2.

Because of the unique chemistry of the Octolig®, the immobilized ligand complex is very insoluble, and is stable in pH ranges from 0.5 to 10.5 and at temperatures from 0°C to over 80°C.



Octolig® has the capacity to retain ions or metal complexes. Before it is loaded with heavy metals, Octolig™ has the appearance of fine white sand. When the Octolig® is loaded with heavy metals, the column changes to the color of the heavy metals it has retained.

The appearance of the silica gel is deceiving. One kilogram (2.2 pounds) of silica gel has a dry or wet volume of 2.2 liters (0.6 gallons). The silica gel has millions of pores, the surface area of which is as much as 700,000 square meters per kilogram.

When the ligands are bound to the silica gel, the heavy-metal-retention capacity of the Octolig® is as much as 1.0 mole per kilogram. In industrial applications, the optimum loading capacities are from 0.2 to 0.6 moles per kilogram.



Advantages
of
Enormous
Stability
Coefficients

 Octolig® has enormous stability coefficients that are several million-to-one to trillions-to-one. This is advantageous when other common chelators, such as ammonia, are present in the waste stream.

The chelator with the largest stability coefficient has the greatest affinity for the heavy metals that are present in the solution.

Enormous stability coefficients enable the Octolig® to remove heavy metals from waste streams, even when other common chelators are present in the solution.

Octolig® is selective only for heavy metals. Benign ions, such as sodium, calcium, sulfate, chloride, etc., are not retained. The chelation capacity of the Octolig® is not reduced by the presence of these benign ions.


Page 1 Page 2 Page 3 Page 4 Page 5 Chemistry Information
Request		 Case
Studies