Activated carbon fiber (ACF) has broad application prospects in dyeing wastewater purification owing to its high specific surface area and hierarchical pore distribution. Natural fiber based ACFs is a group of emerging biomass adsorbent with attractive potential adsorbent properties. Herein, we develop a facile carbonization strategy to obtain a novel biomass ACF derived from the seed hair fibers of metaplexis japonica (MACFs), and the prepared MACFs possess hollow structure and the formation of graphite-like crystallites from MACFs is promoted by high temperature of carbonization. MACFs possess well-developed pore distribution, with a maximum specific surface area and total pore volume of 1882.003 m 2 /g and 1.613 cm 3 /g, respectively. MACFs exhibits the maximum adsorption capacity to be 943.372 mg/g for methylene blue (MB) fitting well with Langmuir model. Furthermore, MACFs can adsorb full solution of 90 mg/l by filtering only one time, proving its fast-adsorption performance. The high adsorption capacity and speed of MACFs are mainly attributed to three factors: high specific surface area and rich pores benefited from the full activation of hollow fibers, strong electrostatic attraction to MB provided by surface groups, and good contact with dye liquor. This work may shed light of the adsorption mechanism of biomass ACFs for the dyeing molecules and pave the way for the development of low-cost and highly efficient adsorbent.
Jun Wang,Qing Zhang,Xingxing Zeng,Jianhua Qu,Jing Wen,Qi Hu
TEMPO system selectively added -COOH while keeping the hollow microtube structure • Oxidation removes cellulose barrier, creates negative charges, traps cations • OMTC reached 79% of equilibrium capacity in 10 s and near-equilibrium in 2 min • Fixed-bed experiment showed excellent hydraulics with optimal density 0.5403 g/cm 3 Within the discipline of treating organic wastewater, the development of a bio-based adsorbent with both an ultra-fast adsorption rate and a high removal efficiency remain a challenging goal. An efficient adsorbent, named oxidized Metaplexis japonica tomentum cellulose microtubes (OMTC), was fabricated. This adsorbent came from the tomentum of Metaplexis japonica seeds. The C6 hydroxyl moieties of cellulose were transformed into carboxyl functionalities by means of a selective oxidation method. The process used a TEMPO/NaClO/NaClO 2 combination while maintaining a weakly acidic pH. The oxidation led to the creation of numerous active sites. At the same time, it preserved the intact natural microtube structure. The structure had a diameter of approximately 20 μm and a wall thickness of about 1.16 μm. An alkali treatment removed impurities. This treatment provided a uniform reaction interface for the subsequent oxidation. After the oxidation, the carboxyl group content on the cellulose surface reached 0.48 mmol/g ± 0.02 mmol/g. The surface also changed from hydrophobic to hydrophilic. The as-prepared OMTC showed a high removal performance toward cationic organic pollutants. Under alkaline conditions, its adsorption capacity increased. It also showed an ultra-fast adsorption rate. Specifically, it reached 79% of the equilibrium adsorption capacity within 10 s and achieved near-equilibrium within 2 min. The oxidized cellulose microtube adsorbent combines the natural high specific surface area with the high-density carboxyl sites introduced by oxidation. The synergistic effect of the two enables rapid and efficient treatment of organic wastewater. Download: Download high-res image (205KB) Download: Download full-size image
危险品化学品经营许可证（带存储）