A fast removal of methyl orange from an aquatic system utilizing activated carbon from waste tamarind wood
Theeradit Phothitontimongkol, Kanyarak Prasertboonyai
Abstract
In this work, activated carbon (ACs) prepared from waste tamarind wood (TW) was used to study the adsorption of the dye methyl orange (MO) in water. The charcoal tamarind wood (CTWs) was impregnated by phosphoric acid (H3PO4) with various weight ratios of H3PO4 and CTWs (1:1 to 4:1) and subsequently activated under atmospheric N2 at 800 °C for 1 h. The impregnated amount of H3PO4 resulted in each activated carbon's surface area and surfaced functional groups from waste tamarind wood (ACTW). When tested in the adsorption of the MO at pH 6, ACTW-3:1 gave a high removal efficiency (99%), similar to ACTW-3.5:1 and ACTW-4:1. Due to its financial aspect, ACTW-3:1 is chosen for additional study. The adsorption results also correlate better with the Langmuir isotherm models than the Freundlich isotherm theories. The maximum adsorption capacity of MO on ACTW-3:1 is 39.84 (mg/g), and the equilibrium is reached quickly at 20 min for fast adsorption. From the kinetic investigation, the adsorption process of MO on ACTW-3:1 is more reliable by the pseudo-second-order kinetic model suggesting chemisorption could be the foremost rate-control step. The reusability of ACTW-3:1 maintains the initial adsorption capacity up to the sixth cycle implying an alternative adsorbent for the water treatment process.