Recuperación de cromo presente en efluentes líquidos contaminados generados en el curtido de pieles mediante la intercalación de bentonitas

Two natural bentonites from Valle del Mantaro (Huancayo, Peru) have been used to diminish and to recover the chromium content of a residual effluent generated at a leather tanning process. The efluent was treated with NaOH and formic acid, with the objective that Cr³⁺ polimerizes forming an effective intercalant agent of the bentonites. The intercalation variables studied were the temperature (20 and 60°C) and the intercalation time (5 and 10 h). The intercalation process allowed to diminish the chromium content of the residual effluent from 635 ppm to 4.06 ppm, as the best result. The pillared clays show specific surface areas in the range of 92 to 134 m²/g and microporous volumes in the range of 0.039 to 0.059 cm³/g.