Cellulose-based composite sponges derived from agricultural wastes for dye removal: Low temperature and non-toxic crosslinking

Abstract

Abstract To enhance the environmental sustainability, the transformation of wastes to be useful aspects have been focused with more attention. In this study, cellulose from residue crops was extracted via microwave-assisted method and fabricated as cellulose/chitosan composite sponges for dye removal. The pore structures with good physical property were introduced via UV crosslinking without heat treatment and followed by freeze-drying method. The optimal crosslinking parameters such as plant types (rice straw, coconut coir, and corn husk), photo-catalyst types (TiO2 and sodium hypophosphite (SHP)), and UV irradiation time were performed. The results showed that cellulose derived from coconut coir with SHP under 15 min of UV exposure exhibited the porosity more than 90% and pore size in the range of 100–120 µm. The dye adsorption was fitted well with the Langmuir isotherm and provided the highest adsorption capacity at 99.01 mg/g with removal percentages of 96.27 ± 0.17% at an initial dye concentration of 50 mg/L. Thus, the low temperature and non-toxicity of the proposed method in this work has potential for converting wastes into value-added products.