Removal of chromium from aqueous solutions by activated carbon produced of cigarette butts

Today, due to the extensive consumption of cigarettes and the presence of cigarette butts in the environment as non-degenerative waste, collecting and converting them into a consumable is essential. Therefore, converting cigarette butts to activated carbon can be a win-win strategy for the environment. Because safe drinking water is a vital factor in the survival of communities, the presence of chromium, as a heavy metal, in the water can be very dangerous. Today, the use of activated carbon is one of the most common methods for removing chromium from water. The present study aimed at determination of the effectiveness of activated carbon produced by cigarette butts in removing hexavalent chromium from aqueous solutions. In this study, NaOH chemical activation was utilized and BET and SEM tests were used to determine the specific area. The effect of pH, adsorption value, reaction time, initial chromium concentration and temperature for chromium removal were investigated and the adsorption rate was determined using atomic adsorption device. The results showed that pre-treatment with NaOH and increasing its concentration led to an increase in the specific surface area of activated carbon. Absorption tests showed that the highest adsorption efficiency was observed at pH 2, 7 g/l of adsorbent, time of 60 min, initial chromium concentration of 50 mg/l and temperature of 25°C. The results showed that adsorption followed the Langmuir isotherm, and the quasi-first order equation is suitable for experimental data. The thermodynamic analysis of the adsorbent showed that the reaction is spontaneous and exothermal. This study showed that cellulose acetate fibers in cigarette filters can be a suitable material in carbonization operations to produce activated carbon with a specific surface area of about 1000 m2/g, which can be used to remove chromium from water.