Mechanochemically activated saponite as materials for Cu<sup>2<hsp></hsp>+</sup> and Ni<sup>2<hsp></hsp>+</sup> removal from aqueous solutions: Fid-Bau Portal

Mechanochemically activated saponite as materials for Cu²⁺ and Ni²⁺ removal from aqueous solutions

Petra, L. / Billik, P. / Melichová, Z. / Komadel, P.

AbstractSaponites are nanosized layered aluminosilicates from the smectite group of clay minerals, which can be further functionalized to prepare low-cost materials for water purification. Mechanochemical activation of saponite was achieved by high-energy grinding in a planetary ball mill. X-ray diffraction, infrared spectroscopy, scanning electron microscopy, thermal analysis, and the determination of cation-exchange capacity and specific surface area were used to characterize parent and functionalized solids. Prepared adsorbents were used for Cu²⁺ and Ni²⁺ removal from aqueous solutions. Compared to the untreated sample, activated saponites had significantly increased capacity to take away metal cations. The equilibrium data showed the maximum of Cu²⁺ and Ni²⁺ uptake of 295 and 129mg/g, respectively. In comparison with the pristine material, the measured values increased by 764% and 170% for Cu²⁺ and Ni²⁺ respectively. The formation of reactive Mg(OH)2 as the saponite decomposition product was also discussed.

Graphical abstract

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Highlights•Mechanochemically activated smectites were prepared by high-energy grinding of saponite.•After activation, the amount of removed Cu²⁺ and Ni²⁺ from water solutions significantly increased.•The removed metal ions form insoluble hydroxides on the surface of ground saponite.•The cations after removal are fixed and unavailable for further ion exchange.