Adsorption of crystal violet from aqueous solution in continuous flow system using bone char

Abstract

In the face of water scarcity and more strict environmental regulation, water treatment is a demand and reuse is being encouraged in diverse production processes. Advanced treatments, such as adsorption, may be indicated for specific and/or recalcitrant contaminants removal, such as dyes, present in textile industries wastewater, for example. However, the conventional adsorbents cost may be unattractive for such a purpose. In this context, bone char, 0.5–1.4 mm particle size, mesoporous structure, produced from tannery, food and cattle breeding waste, was tested to remove crystal violet dye from synthetic effluent, in a lab scale fixed bed adsorption column. A complete removal was observed up to 74 min of column operation. The greatest adsorption capacity (qo = 20.63 mg·g−1) was observed for the lowest flow rate evaluated (Q = 15.4 ± 0.8 mL·min−1) and intermediate bed depth (h = 24 cm) at 27.1 ± 0.9 °C. At the same operational conditions, the experimental breakthrough curve was better predicted by Yan model (qo = 20.42 mg·g−1; a = 1.667; b = 2.93 and R2 = 0.955) compared to Thomas model (qo = 22.44 mg·g−1; kTH = 0.056 mL·mg−1·min−1 and R2 = 0.878).