This review had as aim the bibliography research for the use of aluminosilicates to remove heavy metals from wastewaters. Advanced studies based on parameters that have influence for removal of heavy metals as pH, metal concentration, effect of ligants and removal capacity of zeolites and clays, were reported. These studies demonstrate that aluminosilicates can be successfully used for the removal of heavy metals under the optimized conditions.

As técnicas de difração de raios-X (DRX), análise térmica diferencial (ATD) e ressonância magnética nuclear no estado sólido com rotação no ângulo mágico (RMN-MAS) de 27Al e 29Si foram utilizadas para o monitoramento das etapas de fracionamento de uma amostra de esmectita brasileira, previamente moída, originária de Campina Grande, Paraíba, e utilizada como matéria-prima para a preparação de catalisadores ácidos. As frações foram obtidas por tratamentos físico e químico. As análises de DRX das frações areia e silte mostraram que ambas possuem predominantemente quartzo e feldspato, respectivamente. Os resultados de DRX da fração argila, saturada com K+ e aquecida, confirmaram tratar-se de argilomineral do grupo 2:1, enquanto a análise da fração argila, saturada com Mg2+ e glicolada, confirmou a presença de esmectita. Os resultados de RMN-MAS de 27Al e 29Si evidenciaram ser a fração areia constituída por cerca de 79% de quartzo; a fração silte possui 55% de quartzo, e a fração argila, rica em esmectita com baixa substituição isomórfica de Si por Al, contém 38% de quartzo.

X-ray diffraction (XRD), differential thermal analysis (DTA) and 27Al and 29Si solid state MAS-NMR techniques were used to monitor the fractionation steps of a brazilian smectite, previously crushed, from Campina Grande, Paraíba. The sand, silt and clay fractions were obtained by physical and chemical treatments. The XRD analysis of sand and silt fractions showed that both fractions had predominant quartz and feldspar, respectively. The XRD results of the K+ saturated and heated clay fraction confirmed that the natural clay belongs to the 2:1 clay-mineral group, whereas the analysis of the Mg2+ saturated and glycolated clay fraction confirmed the presence of a smectite group clay. The MAS-NMR results of 27Al and 29Si showed that the sand fraction contains 79% of quartz and the silt fraction contains 55% of quartz, while the clay fraction is rich in smectite with low isomorphic replacement of Si by Al, and contains 38 % of quartz.