A Comparison Study on Methylene-Blue Adsorption Between Moso Bamboo Fiber and Parenchyma Cells

This investigation aims to compare the methylene blue (MB) removal by adsorption from water, using raw and delignified bamboo cells, i.e. fiber cells (FCs) and parenchyma cells (PCs). FCs and PCs were characterized using SEM, FTIR, BET surface area, and XPS before and after delignification and MB absorption. Compared with FCs, PCs had a looser cell wall and a larger cell cavity, indicating that PCs have more physical adsorption spaces. Both PCs and FCs had higher specific surface areas and more pore-rich structures after removing lignin. Therefore, the adsorption results show that both PCs and FCs had greater adsorption capacities after removing lignin, which were 29.6 and 23.9 mg/g, respectively. The kinetics and isotherm results revealed that the adsorption process on MB corresponded to pseudo-second-order models and monolayer adsorption (the Langmuir model), respectively. PCs always had better adsorption capacities than FCs, which was due to the fact that more MB clusters were observed on PCs and a larger increment of peak corresponded to C-N/C-O in PCs. This study provides a natural material as a more economical and widely used adsorbent in adsorption applications.