RESUMEN
The waste water containing dyes is difficult to be biochemically treated because of its deep color. Adsorption becomes an important treatment method for this kind of waste water. The iron organic framework was rapidly synthesized at room temperature, and characterized by IR and XRD. Adsorption properties of the materials were tested using four anonic dyes solutions. It was found that the iron organic framework could be formed rapidly, with higher surface area and pore volumes. The pH value of zero point charge was 3.7. The adsorption experiments showed that the iron organic material could remove more dyes in acid solution. The dye adsorption capacity increased with increasing dye concentration. These adsorption data fitted well with Langmuir thermoadsorption equation. The calculated parameter from Langmuir adsorption indicated that the adsorption process could be performed easily. The second order kinetic equation could describe the adsorption data. In addition, the structure of dyes could affect the adsorption process. The metal complex dyes could be quickly removed.
Asunto(s)
Colorantes/química , Hierro/química , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/química , Adsorción , Concentración de Iones de Hidrógeno , Cinética , SolucionesRESUMEN
The fly ash from coal combustion was used as adsorbent for the removal of binary mixtures of dyes from aqueous solution. The binary solution included reactive red 23 and one of reactive blue 4, reactive yellow 4, acid black 1 and acid blue 193. The experimental findings show the removal efficiency of reactive red 23 is about 60% -70% while the removal of acid dyes exceeds 90%. The removal value of reactive blue 4 is about 85%, while the value is only 50% for reactive yellow 4. The adsorption kinetic data are good fitted with the pseudo-second-order kinetic model. The external diffusion coefficient solution is in the order of 10(-4) cm x s(-1), while the intraparticle diffusion coefficient is in the order of 10(-8) cm2 x s(1). Because all B(N) numbers are smaller than 100, adsorption of dyes on fly ash is mainly controlled by the external diffusion mechanism.