Retention of pollutant gases: Comparison between clay minerals and their modified products

The clay is a natural mineral resource that can be used for different applications: Recently some studies indicate that it can also be used for retention of gases at room temperature conditions. Several researchers study the retention of gases and have analysed physicochemical characteristics of the clays and their influence on capacities for adsorption gases. It has been demonstrated that the clays can be used as solid adsorbents in natural conditions and after modifications. In that way the natural smectite clays are better than natural kaolinites. Nevertheless, after appropriate physicochemical modifications, it is possible to obtain good adsorbents by using both types of clays as raw materials. Different activities related to our modern life, which have originated environment changes, have increased the emission pollutant gases and then have influenced health. Retention of gases by clays and their modified products which can help us to clean polluted atmosphere are shown in this review.