Utilization of New Activated Carbon Derived from Oak Leaves for Removal of Crystal Violet from Aqueous Solution

Abstract

Significant negative environmental impact has been noticed at the campus garden of Gdansk University of Technology in Gdansk, Poland, when the withered leaves of Quercus robur Oak Tree (OL) cover large areas at such places. In this regard, an attempt has been made to recycle the most abundant agricultural leaf waste into a high quality local activated carbon (LAC) for use in the decolorization processes of dye industrial wastewater. A novel AC prepared from OL was studied for removing of crystal violet dye (CV) from aqueous solution under various experimental conditions. The effect of an OLAC adsorbent dose (5-30 mg/25ml), pH (3.09.0), two levels of shaking (90 and 130 rpm) under different contact times as compared to the sorption process at soaking in a beaker for one day, and CV initial concentrations (5-40 mg/l) were all studied in a batch mode process. The sorption exhibited high efficiency for CV adsorption and the equilibrium state could be achieved in 20 minutes for the different CV initial concentrations. CV uptake was proved to increase with the increase in OLAC dose, pH, shaking rate, contact time, and CV initial concentration. The applicability of Lungmuir and Freunflich isotherm equations was investigated. The Freundlich isotherm exhibited a better fit with the experimental data with linear regression value (R 2 ) of 0.9937, although the isotherm parameters of the Langmuir isotherm also indicate favourable adsorption. The maximum capacity (qm) obtained from Langmuir isotherm model was 41.15 mg/g for CV. The results of this study demonstrated the feasibility of applying the low cost and abundantly available OL as a raw material for the preparation of high-quality AC the for removal of CV from aqueous solution.