Behaviour of fixed-bed column for the adsorption of malachite green on surfactant-modified alumina.

Prepared surfactant-modified alumina (SMA) was used to remove malachite green (MG) from aqueous media. At a dose of 10 g/L, SMA removed ∼ 99% MG (initial concentration 100 mg/L). The adsorption capacity (Q max) of SMA was 185 mg/g as calculated from Langmuir isotherm. In a fixed-bed column study, using the MG-spiked distilled water, the column design parameters were evaluated by Logit model at a bed depth of 10 cm. The adsorption rate constant (K) and adsorption capacity (N o ) was obtained as 0.002636 L/(mg h) and 76283.16 mg/L for the minimum bed depth 3.33 cm in the 1st cycle. Acetone was used for desorption of MG from SMA. In batch regeneration study, regenerated SMA could remove only ∼ 80% of MG under the same experimental conditions. In column regeneration study, the efficiency of the regenerated bed decreased and the values obtained as, K = 0.007931 L/mg h and N o = 12341.08 mg/L for the minimum bed depth of 6.83 cm. Column study was conducted with the real MG bearing wastewater (MG concentration w...