Adsorption behavior of Azo Dye C. I. Acid Red 14 in aqueous solution on surface soils

Azo dyes have received considerable attention because of their association with various human health problems.The aim of the investigation is to determine the adsorption behavior of azo dyes in aqueous solution on DG06,GSE17200,and GSE17201 soils using C. I.Acid Red 14 (AR14) as example.The experimental results indicate that the Freundlich model expresses the adsorption isothelm better than the Langmuir model and the pseudo-second-order model achieves adsorption of AR14 Oil the three soils well.Based on the pseudosecond-order model.the adsorption thermodynamic of AR14 on DG06 soil have been studied and the thermodynamics parameter of △G0 is determined and △G0 value shows the adsorption process of AR14 on DG06 is mainly physical in nature.Furthermore, the effects of temperature,pH and salinity (NaCl) on adsorption have been investigated.The decrease in pH or the increase in salinity enhances the adsorption of ARl4 by DG06, GSE17200, and GSE17201.