Carbohydrazide modified polyacrylonitrile fiber as efficient and recyclable furfural adsorbent

Abstract A novel carbohydrazide functionalized polyacrylonitrile fiber (PANJF) was designed and prepared for removal of furfural from water. Compared with other amino-containing functionalized fibers, the PANJF fiber exhibits the highest adsorption capacity due to the highest reactivity of carbohydrazide. Batch experiments were performed to explore the influence of pH, initial concentration of furfural, dosage of adsorbent, adsorption time, and temperature on the process of adsorption. Under the optimized condition, the maximum adsorption capacity of PANJF for furfural reaches 140.4 mg g−1. Kinetic and isothermal curves show that the adsorption process is in accordance with the pseudo-second-order model and the Langmuir isothermal adsorption model. Furthermore, the thermodynamic result indicates that the furfural adsorption on PANJF is an endothermic and spontaneous process. More satisfactorily, the PANJF still maintains 90% removal efficiency even after five cycles, which certifies it is an excellent scavenger and can be utilized to remove furfural in practice.