Removal of 2-naphtol orange by industrial rose and lavender solid by-products in dynamic conditions

Rosa damascena Mill. (RD) and Lavandula angustifolia Mill. (L) biomasses – by-products of essential oil manufacturing were utilized as renewable and nature-friendly adsorbents for removal of 2-naphthol orange (2NO) in column adsorption model (dynamic conditions). The amount of proteins in the biomasses were 11.60±0.68% for RD and 8.65±0.20 for L, and the polyuronide content for both residues was around 7.50%. The dynamic adsorption of 2NO was investigated in five solutions with different pH, namely 0.1 N H2SO4 (1.21), deionized water (3.63), 50 mM citrate buffer (5.49), 50 mM phosphate buffer (8.30) and 0.05 N NaOH (12.80). Preliminary washing of RD and L residues with 0.1 N HCl increased their removal efficiency compared with water washed biomasses. At pH range from 1.21 to 5.49 the 2NO removal was above 89.0±0.1% for RD and 84.2±0.1% for L. The present work demonstrated that RD and L biomasses were able to remove 2NO in dynamic conditions (column adsorption) from water solutions with 89.0±0.1% and 84.2±0.1% efficiency, respectively.