Removal of Organic Dye from Wastewater with δ-MnO_2

The adsorption characteristics of methyl orange simulating dye on δ-MnO_2 and their main affecting factors were studied.The results showed that the adsorption-pH curves have shown reverse S-shape in(0.05*!mol/L) NaNO_3 solution.In addition,the tendency of the adsorption was downward with the increasing of pH value,which was more evident in the middle than at two ends.Langmuir adsorption isotherm was very fit for the adsorption date.Temperature had little effect on adsorption isotherm.But adsorption isotherm decreased evidently with the increasing of adsorbent dose.When the temperature was 25*!℃ and pH6.0,the maximum amount of adsorption was 263*!mg/g.It was found that the adsorption of methyl orange on δ-MnO_2 was irreversible.