Filtering material

A polymer of globular space structure (SGS-polymer) synthesized by the unique patented technology is used as a filtering material in the Geyzer cartridges. SGS-polymers is a hard highly porous filtering material combining adsorption, ionic exchange, micro-filtration and demulsifying (coalescence, removal of emulsions) properties.

Advantages of the material in purification of drinking water

• Micro filtration, ionic exchange and sorption combined in one filtering element;
• SGS polymer forms pores of labyrinth structure prevnting punching of strained sedment into purified water;
• Improved filtering rate as compared with traditional granular filtering materials;
• Ion-exchange properties of a material enabling remove of iron and heavy metals ions from purified water;
• Quasi-softening effects means change in the crystal structure of salts of hardness (calcium and magnesium carbonates). Temporary hardness of water up to 4.5 mg equiv/l does not cause sedimention. If hardness value is higher, there is no fur mantled on heating elements, and deposits could be easily washed with water;
• Bacteriostatic property- polymerized silver embedded in the material in the indelible form prevents reproduction of strained microorganisms;
• Regeneration capacities - mechanical and chemical cleaning of the polymer with accessible domestic means.

New type of the ion-exchange resins - polymers with a space (three-dimensional) globular structure (SGS-polymers) were first prepared in USSR in the middle of 20th century. At present, only the Geizer Joint-Stock Company can commercially produce these materials. SGS-polymers are principally new materials for which three types of filtration, namely mechanical, sorption, and ion-exchange filtration are possible. None of known sorption materials except SGS-polymers allow treatment to remove such a large assortment of chemical compounds as SGS-polymers.

SGS-polymers are macromolecular compounds which can be prepared from various monomers, e.g. resorcin, pyrocatechol, hydroquinone, melamine, carbamide, etc. Microglobules, i.e. long polymeric chains convoluted in clew are formed in synthesis of the SGS-polymers. Being bound these microglobules provide porous and simultaneously mechanically rigid structure form.

Microglobules possess large internal surface area (up to 500 m2*g-1); their surface is coated with active functional groups participating in the ion-exchange processes. The ions removed directly interact with a chemically-active polymer surface excluding their diffusion into the globule bulk which is typical for ion-exchange resins /Fig. A, B/.

A	B

As a result, the rate of the volume filtration of the SGS-polymers is greater by a factor of 10-20 as compared to common granulated ion-exchangers. This is a decisive advantage of the SGS-polymers. Mechanical admixtures are predominantly removed in the outer near-surface layers; the pore size can vary in any range from 0.01 to 3.5 micron. Changing the synthesis conditions the required porosity of the material can be obtained with an accuracy of no more than 10%.

At present, nearly 30 modifications of the SGS-polymer were studied and the operation procedures for their production were developed. The materials exhibiting both cation- and anion- exchange properties were also synthesized.

The fields of application of the SGS-polymers are very wide and involve purification of:

• Drinking water and hot water;
• Juices, vines, sunflower-seed oil;
• Technical liquids, acids and alkalis;
• Waste waters, including those contaminated with petroleum products;
• Gases, including exhausts.

SGS-8 sorbent based on resorcin exhibits the best results in complex treatment of water to remove harmful pollutants. This polymer meets the rigid requirements of the Russian and International (NSF) Standards and can be used in systems for treatment of the drinking water. Dissolved chemical elements (from aluminum to radioactive metals) and their compounds are removed from water according to the ion-exchange and sorption mechanisms

The SGS-8 sorption capacity is comparable with best brand activated carbons which provide removal of active chlorine, chlorine-containing compounds, and organic compounds. All the coarse particles with a size greater than the pore diameter are mechanically filtered off on the sorbent surface. The filtration channel has a complex tortuous profile with a gradient porosity which prevents discharge of removed impurities into the purified water often happened at pressure jumps. The amount of free channels in the material only gradually decreases in the course of its operation decreasing the head of the purified water. This allows prolonged multiple operation of the filtration element based on the SGS-8 material. The labyrinth structure of the SGS-8 sorbent acts as a barrier for microorganisms. The major fraction of bacteria and viruses having the oblong shape (from 0.5 to 20.0micron) are trapped in the tortuous sorbent channels. To suppress growing of micro-organisms sorbed in the polymer this material is modified with silver added in the form preventing its migration into the purified water.

Quasi-softening is the unique property of the SGS-8 material. On water passing through the sorbent material the structure of salts providing water hardness is changed. As a result, no deposits upon boiling are formed and water exhibits the salutary effect on the living organism. This material possesses high strength and allows mechanical treatment (to prepare cylinders, discs, etc. for filtration elements). Compact and efficient filters based on SGS-8 sorbent are unitized in accordance with main international standards. The SGS-polymer sorbent is successfully used for water treatment in the regions contaminated with various pollutants after the Chernobyl accident.