Evaluation of the Metallurgical Dust Sorbent Efficacy in Reactive Blue 19 Dye Removal from Aqueous Solutions and Textile Wastewater

The present study shows sorption capacity of the metallurgical dust, for the anionic dye—Reactive Blue 19, from aqueous solutions and real textile wastewater. The sorption processes were carried out in batch method at six doses of: 2, 5, 10, 20, 50, and 100 g/L. The highest maximum sorption capacity of the dust in relation to the dye from aqueous solution has been estimated for sorbent dose of 2 g/L, it was 319.2 mg/g, and the removal efficiency (RE) was at the level of 62.7%. The experimental data have been analyzed by the Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models, using nonlinear regression. To determine the best fit isotherm 3 error functions were used. Reactive Blue 19 from aqueous solutions was probably bound by the electrostatic attraction between the anionic dye and positively charged surface of the dust. Comparing sorption of the Reactive Blue 19 dye from aqueous solution and textile wastewater, it was observed that for all doses of the metallurgical dust the dye was removed in higher amounts from wastewater, probably due to the presence of the auxiliary substances used in dyeing processes. The RE of the dye was very high both from aqueous solution and textile wastewater, in the range of 84.90–99.92% and 96.48–99.99%, respectively. The results showed that dust from a steel plant, containing iron oxides, can be used as low-cost and effective sorbent to remove reactive dye from aqueous solution and textile wastewater.