Nowadays, by rapid development of economies and industries, water contamination through the heavy metal ions (toxic, non-toxic and radioactive) is a great concern and an important environmental problem. Currently, numerous techniques such as chemical precipitation, coagulation, ion-exchange, filtration, reverse osmosis, bio- logical treatment and physical adsorption are presented by researchers for removing and recycling heavy metal ions from wastewater. Among these methods, adsorption approach is one of the most efficient techniques for the elimination of heavy metal ions from aqueous solutions. There are a number of low cost absorbent such as agri- cultural and industrial solid waste such as lingo-cellulosic materials, wheat bran, peanut shell, moss peat, fly ash, bagasse, tree fern, gram husk, nanostructures (such as TiO 2 , SiO 2 , SnO 2 , ZnO, etc.), 3D porous structures (aerogels), etc. which have been developed and tested to efficient removal of heavy metal ions from wastewater. In this study, a critical review of the applications of aerogels in water and sewage purifications is performed. For this reason, different kinds of aerogel namely organic, inorganic and organic-inorganic hybrid aerogels are inves- tigated. It is concluded that the most applicable aerogels used in these studies are graphene-based aerogels due to more porous structure as well as simplification of their modification. Also, in this review paper, for the first time we summarized and highlighted the recent literature information about heavy metal ions and theirs removal methods from aqueous pollutants and wastewater/water, adsorption kinetics, isotherms and thermodynamics models by different type of three dimensional (3D) porous structure. In additional, in this review article, the in- fluence of various parameters such as pH solution, temperature, initial concentration of heavy metal ions, com- position, contact time, coexisting ions and adsorbent dosage on the adsorption process of heavy metal ions were investigated.

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