Neutralizers against Environmental Protection

A widespread recognition of the need to develop technologies for pollution control has arisen in oniy relatively recent times. This has been a result of increased awareness of the effects of pollution on the health and longevity of both human beings and the earth s fragile ecosystems. Therefore it is not surprising to find that clays were not used for environmental protection to any great extent until quite recently. 

To understand the role of clays in nature and their beneficial effects, it is important to have the preliminary knowledge about origin of clays and their transformation in nature. 

In nature, generally three mechanisms are in operation for the formation of clays. They are inheritance, neoformation and transformation. 

Inheritance Clay minerals remained in a natural deposit and originated from reactions that occurred in another area during a previous stage in the rock cycle. This type of clay is inert in nature. Its stability may result either from slow reaction rates or from being in chemical equilibrium. Clays that have inherited their crystal structure are indicators of their provenance. 

Neoformation In this case, clay is precipitated from solution or has been formed from reactions of amorphous material. These clays have precipitated in response to in situ conditions. 

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MDF-lOO was advertised as being equally effective against biological agents. In response to the terrorist anthrax letters of 2001, MDF-lOO was considered by the Environmental Protection Agency (EPA) as a decontaminant for facilities. Use of MDF-lOO was cancelled by the EPA in March 2002 because of concerns that it did not neutralize anthrax spores with sufficient speed. 

This specification outhnes a three-coat epoxy-polyamide painting system for the protection of steel surfaces subject to industrial exposure, marine environments, and areas subject to chemical exposure such as acid and alkali. This system, when properly applied and cured, is capable of giving excellent protection to steel surfaces in Environmental Zones 2A (frequently wet by fresh water), 2B (frequently wet by salt water), 3A (chemical, acidic), 3B (chemical, neutral), and 3C (chemical, alkaline) but not in potable water tanks. Although the coating herein specified has exhibited good chemical protection, its resistance against specific chemicals should, in the absence of applicable case histories, be appropriately tested. 

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