Sorptive Removal of 133Ba from Aqueous Solution Using a Novel Cellulose Hydroxyapatite Composite Derived from Cigarette Waste

Abstract

133Ba is a hazardous radionuclide generated during the operation of nuclear power plants. 133Ba needs to be removed from waste solutions because its half-life (10.55 years) and gamma energy pose a significant threat to human health. Cigarette butt (CB) is a waste that causes serious environmental problems. Various types of adsorbent materials are prepared based on the cellulose in its structure. The focus of the present study is to synthesize a novel composite material derived from CBs and to investigate its 133Ba removal capability. Microfibrillated cellulose (MFC) obtained from CBs was modified with hydroxyapatite (HAp) via the co‐precipitation method and converted into a composite adsorbent for the removal of 133Ba ions. Response surface methodology (RSM) based on Box‐Behnken Design (BBD) was employed for the examination of process variables such as initial pH, metal concentration, and adsorbent amount on 133Ba sorption. XRD and FTIR data confirmed the successful isolation of cellulose and the modification of the cellulose surface with HAp. The model F-value (100.04) and R2 (0.99) suggested that the proposed model was significant. Optimum conditions were determined as initial pH of 8, contact time of 134 min, and concentration of 0.01 mol/L, and the barium sorption capacity of MFC‐HAp was found to be 0.75 mmol/g under these conditions. The maximum monolayer barium sorption capacity was determined to be 2.92 mmol/g. Combining cellulose and HAp to be a novel composite adsorbent is useful for reusing CB waste and promising for removing 133Ba ions from aqueous solutions.