Nano-montmorillonite-based porous material prepared by gel casting: structure and adsorption properties

Porous materials (P-Mt) were prepared via gel casting method by nano-montmorillonite (Nano-Mt) powder. P-Mt possessed adsorption capability to low concentration Cr3+ in tanning waste water. The initial concentration of Cr3+ was 10 mg/L (pH = 3 ± 0.1), its removal rate and adsorption quantity were 72.50% and 5.80 mg/g, respectively, when P-Mt was sintered at 600°C. While sintering temperature was higher than 700°C, its adsorption capacity to Cr3+ was damped because crystal shape and lamellar structure of P-Mt were significantly changed. It demonstrates that 600°C was a better sintering temperature at which P-Mt could efficiently remove Cr3+ in tanning waste water. Moreover, the problem of easily aggregation and difficult recycle in liquid with Nano-Mt powder was solved according to this method.