Removal of cobalt and strontium by adsorption using Brewer's spent grain formed by pyrolysis

One byproduct of brewing beer is Brewer's spent grain (BSG), which is reused in animal feed. However, BSG has valuable potential for other products such as biochar because of its high protein and fiber content. Radioactive waste is one of the biggest concerns in Korea because of the permanent shutdown of the Gori nuclear power plant. In this study, we aimed to use BSG-850, a biochar originating from BSG after pyrolysis at 850 degrees C, for the adsorption of cobalt (Co) and strontium (Sr), which are two radionuclides that contribute to radioactive waste. The adsorption capacity of Co and Sr was reinforced with increased temperature which are 3.304, 4.659, 5.516 mg/g (Co) and 1.462, 2.54, 3.036 mg/g (Sr) at 298, 308, and 318 K, respectively. The reusability of BSG-850 capacity was 75.3, 47.8, 43.6, 36.2% and 93.6, 84.2, 57.2, and 32.7% after 1, 2, 3, and 4 cycles, for Co and Sr, respectively. In the presence of other competitive ions, the adsorption capacity decreased. The adsorption capacity and properties of BSG-origin biochar for Co and Sr were confirmed and BSG can be a desirable option for solving radioactive waste issue.