APLICACIÓN DE SAPOGENINA COMO AGENTE SURFACTANTE, EN LA REMOCIÓN DE METALES Cd Y Ni EN MODELOS DE AGUA

Abstract

In this paper we applied the spherical agglomeration technique for the removal of cadmium and nickel in model solutions of 0.5, 1 and 2 mg/L, since this technique has been applied to very high concentrations of metals show high removal efficiencies. This technique consists of four main stages: precipitation, hydrophobization, wetting and agglomeration which were considered and optimized parameters of pH, stirring rate and dosage. The agent was applied in the stage of hydrophobisation was natural sapogenin which helped to reduce the operating costs of the technique. It was applied 32 factorial experimental design with two factors (dose of sapogenin and concentration of heavy metal), and three levels, respectively. Colloid formation was analyzed by scanning electron microscopy, which was subject size between 0.5 and 5 microns. Residual concentration was determined by atomic absorption spectrophotometry for nickel was 0.02 mg/L thereby meeting the NOM-127-SSA1-1994 and NOM-201-SSA1-2002. The minimum concentration of cadmium was 0.015 mg / L, this value is within limits established by the NOM-001-SEMARNAT-1996 and NOM-002-SEMARNAT-1996. Statistical analysis was applied response surface which showed that the best conditions for removal are obtained at a concentration of 2 mg/L of contaminant in both cases with a dose of 1.5 g of sapogenin/g of metal Ni and Cd sapogenin 2.5 g/g of metal. It was found that the technique gets high removals at low concentrations of pollutant in water models.