Preparation and characterization of novel cellulose based adsorbent with ultra-high methylene blue adsorption performance

Abstract

Although zeolitic imidazole framework-8 (ZIF-8) has been widely used as the organic dye adsorbent, a suitable carrier is needed to solve the issues of low stability and poor dispersibility in water. Poly(acrylic acid) was grafted onto cellulose to prepare MAA aerogel with more active sites for MB adsorption which was applied as the carrier for ZIF-8. Here, ZIF-8/MAA composite aerogel was prepared by in situ growing the ZIF-8 nanoparticles onto the walls of the pores of MAA aerogel. The prepared adsorbent was characterized by SEM, FTIR, and TG analysis. A series of adsorption experiments were carried out to optimize the various parameters affecting MB adsorption behaviors (the adsorbent dosage, solution pH, initial MB concentration, adsorption time, and adsorption temperature). The experimental data for the adsorption process followed a pseudo-secondary kinetic model, more in line with the Langmuir isotherm (R2 = 0.992), with a maximum adsorption capacity of 1492.99 mg/g. The prepared adsorbent exhibited great reusability even after five repeated cycles of adsorption-regeneration. The adsorption mechanism was discussed in depth. Thus, the prepared ZIF-8/MAA aerogel can be used as an environmentally friendly, efficient, stable and reusable adsorbent for MB in wastewater treatment.