Commercially Biochar Applied for Tartrazine Removal from Aqueous Solutions
Maria-Loredana Soran, Mariana Bocșa, Stelian Pintea, Adina Stegarescu, Ildikó Lung, Ocsana Opriș
Abstract
Biochar gained attention due to its definite physico-chemical characteristics and because it is a cost-effective and efficient adsorbent. In this paper, commercial biochar was tested for the removal of tartrazine from aqueous solutions. Thus, the optimum experimental conditions were determined for several parameters (pH, temperature, initial concentration of tartrazine, biochar dose, and contact time). The concentration of tartrazine residues was determined using UV-Vis spectrophotometry. The best experimental results were obtained at 1 mg L−1 concentration of tartrazine, pH 2, 30 °C, 18 min, and 0.9 g L−1 adsorbent dose. The maximum removal efficiency of tartrazine obtained in optimum conditions was 90.18%. The experimental data were analyzed by the isotherm and kinetic models. The isotherm and kinetics of tartrazine removal on biochar follow the Langmuir isotherm and pseudo-second-order kinetics, respectively. According to the Langmuir isotherm model, the biochar showed a maximum adsorption capacity of 3.28 mg g−1. In addition, biochar demonstrated a good reuse potential and therefore can be used for the removal of tartrazine from aqueous solutions.