Removal of reactive dyes from their aqueous solutions using Moringa oleifera seeds and Grewia venusta peel

Moringa oleifera seeds (MOS) and Grewia venusta peel (GVP) were used in this study as biosorbents. The adsorption behaviours on two dyes were investigated through batch experiments. The best conditions for the maximum indigo carmine removal (99%) were found to be at pH 2, with 0.5g of GVP and 150mg/L as initial concentration of dye solution. In the same conditions at pH 5, the maximum removal was 85% when using MOS. The equilibrium adsorption data were fitted with the Freundlich model when using MOS (R-2=0.9968) and Langmuir model when using GVP (R-2=0.9957). In a methyl orange case, the adsorption capacity of MOS is 31.25mgg(-1) and the one of GVP is 5.78mgg(-1). In an indigo carmine case, the adsorption capacity of MOS is 91.74mgg(-1) and the one of GVP is 188.68mgg(-1). This study contributed to a better understanding of methyl orange and indigo carmine dyes removal process from aqueous media by M. oleifera seeds and highlighted the sorption properties of G. venusta peel which is rarely used as absorbents in adsorption process. According to the obtained results, MOS and GVP may be potentially used in industry as natural biosorbents for textile dying wastewater treatment.