MIL-53(Fe)-loaded polyethyleneimine-cellulose aerogel as adsorbent for arsenic removal

This work focuses on fabricating a new type of cellulose-based aerogel composite consisting of hydroxypropylmethylcellulose (HPMC), MIL-53(Fe), and polyethyleneimine-grafted nanocellulose (PEI-NC) for arsenic removal. The aerogel composites were prepared through the sol-gel method and freeze-drying. The physical properties and adsorption performance of the prepared composites were determined. Under the optimized condition, the composites could be prepared using 2% HPMC, 1% PEI-NC, and 1% MIL-53(Fe) using 1.8% N,N-methylenebisacrylamide (MBA), and 1 % glutaraldehyde as crosslinkers. The obtained aerogel composites showed excellent stability in water and good water uptake capability. The composites were characterized by FTIR and SEM-EDS, showing a hierarchical 3d-network formation with a homogeneous distribution of MIL-53(Fe). The adsorption study demonstrated that the optimum pH for As(III) and As(V) adsorption was pH 11 with a contact time of 6 and 12 h, respectively. The adsorption kinetics followed the pseudo-second-order reaction model. The isotherm of As(III) and As(V) adsorption could be fitted to the Freundlich model and the Langmuir model, respectively, with the maximum adsorption capacity of 32.32 and 23.81 mg/g, respectively. The composites were successfully applied to remove arsenic from wastewater from the petroleum refining industry.