Modified Sawdust for the Removal of an Azo Dye from Water: Removal optimization with Box–Behnken design

Chemically modified sawdust was used for the removal of Methyl Orange dye from water. The diethylenetriamine (DETA) used for modifying sawdust. The structure and morphology of the sawdust and DETA-sawdust were characterized and compared by power the fourier transform of infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Adsorption characteristics of the modified sawdust were examined by using Methyl Orange dye. The effects of various parameters viz. adsorbent dose, agitation rate, contact time and initial solution pH were investigated for the removal of Methyl Orange by applying Box–Behnken design. The DETA-sawdust had a high uptake capacity and removed Methyl Orange dye (200 mg L-1) of about 83% with 3.4 g L-1 of adsorbent, in 46 min. It was revealed that after ten cycles of adsorption and desorption, the adsorbent retained its promising adsorption ability.