Center for Water Resources Cycle Research, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, South Korea.
Future Environmental Research Center, Korea Institute of Toxicology, 17 Jeigok-gil, Munsan, Jinju, Gyeongsangnam-do 52834, South Korea.
Bioresour Technol. 2016 Nov;219:185-195. doi: 10.1016/j.biortech.2016.07.098. Epub 2016 Jul 26.
Biomass-based granular activated carbon was successfully prepared by entrapping activated carbon powder derived from spent coffee grounds into calcium-alginate beads (SCG-GAC) for the removal of acid orange 7 (AO7) and methylene blue (MB) from aqueous media. The dye adsorption process is highly pH-dependent and essentially independent of ionic effects. The adsorption kinetics was satisfactorily described by the pore diffusion model, which revealed that pore diffusion was the rate-limiting step during the adsorption process. The equilibrium isotherm and isosteric heat of adsorption indicate that SCG-GAC possesses an energetically heterogeneous surface and operates via endothermic process in nature. The maximum adsorption capacities of SCG-GAC for AO7 (pH 3.0) and MB (pH 11.0) adsorption were found to be 665.9 and 986.8mg/g at 30°C, respectively. Lastly, regeneration tests further confirmed that SCG-GAC has promising potential in its reusability, showing removal efficiency of more than 80% even after seven consecutive cycles.
以废咖啡渣为原料制备的活性炭粉末被成功包埋于海藻酸钠珠中，制备出生物质基颗粒活性炭（SCG-GAC），用于从水介质中去除酸性橙 7（AO7）和亚甲基蓝（MB）。染料吸附过程高度依赖 pH 值，且基本不受离子效应的影响。吸附动力学可用孔扩散模型很好地描述，表明孔扩散是吸附过程中的限速步骤。平衡等温线和吸附等焓表明，SCG-GAC 具有能量非均相的表面，且在本质上是一个吸热过程。在 30°C 下，SCG-GAC 对 AO7（pH 3.0）和 MB（pH 11.0）吸附的最大吸附容量分别为 665.9 和 986.8mg/g。最后，再生实验进一步证实了 SCG-GAC 具有良好的重复使用潜力，即使经过七次连续循环，去除效率仍超过 80%。
