Water Treatment : Sewage

Industrial waster water filtration requires filter media of different cation exchange capacities and media mesh sizes, depending upon the chemistry of the contaminant and the nature of the filtration process.  For this purpose the TSM 140 media, produced in a number of mesh sizes, generally ranging from -4+8 mesh to -14+40 mesh, has many applications.

The following is a list of cations which can be removed by Steelhead Specialty Minerals zeolites:

The high cation exchange capacity (C.E.C.) of Steelhead Specialty Minerals zeolites combined with their selective affinity for specific cations make them uniquely suited to various applications in water treatment. Natural zeolites have been shown to be effective in industrial and municipal waste water systems.

One of the first full scale projects to incorporate natural zeolites in a municipal tertiary water treatment system was built for the Tahoe Truckee Sanitation Agency. This system, designed by CH2M Hill, utilizes zeolite as an ion exchange medium for the removal of ammonium (NH+4). The municipal effluent containing ammonium is passed through the natural zeolite which adsorbs the ammonium ion. The efficiency of ammonium removal is dependent upon temperature, water quality, and rate of flow. Regeneration of the natural zeolite bed for reuse is achieved by passing a brine solution through it. The regenerant is then passed through a stripping unit and the ammonium concentrated as ammonium sulfate.

A pilot project near Denver, Colorado, is using natural zeolites for the removal of ammonium in a potable water system. Similar systems are in production which remove pollutants including heavy metals and radioactive ions from industrial effluents.

An alternative method to a typical tertiary water treatment plant is to apply effluents over natural soils. The soil filters the pollutants from the water as it gradually percolates to the natural ground-water table which may be eventually recovered from wells for reuse. The soil, as an ion exchange medium, is regenerated by way of crop production capable of removing many of the pollutants. A major limitation of such systems is the requirement for percolation which typically necessitates the use of a sandy soil type not ideal for ion exchange. The low cation exchange capacity of these sandy soils can then be enhanced through the additions of Steelhead Speicalty Minerals zeolites which will not impede percolation. Tests of this system were carried out by Dr. Ian Pepper of the University of Arizona. In these tests, a turf grass was used to regenerate the system, and adequate efficiencies of pollutant removal were found to be attainable. Additions of natural zeolites in these systems may be found to favorably improve the holding of heavy metals. Further testing is required to full demonstrate this possibility.

Systems for the specific removal of cations from industrial wastes utilizing natural zeolites as a component of the filter medium have been commercialized. These systems have successfully recovered precious metals from plating operations, as well as, basic industrial pollutants.



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