Porous cellulose beads intercalated with calcium carbonate nanoparticles for dye adsorption

About 200,000 tonnes of dye waste is generated annually, polluting our water resources. Dye adsorp-tion using biodegradable cellulose is of great interest because cellulose is abundantly available at a low cost, and secondary pollution can be prevented. In this study, porous cellulose beads (PCBs) were synthesised and characterised for methylene blue (MB) dye removal. The effects of calcium carbonates (CaCO3) nanoparticles on PCBs properties and MB dye removal were further studied. PCBs with varied amounts of CaCO3 nanoparticles (0.01, 0.03 and 0.05 wt.%) were successfully syn-thesised through phase inversion. The Brunauer-Emmett-Teller surface area increased from 2.67 to 12.83 m2/g. The dye removal efficiency (R) increased from 88.12% to 97.04% at the adsorbent dosage of 0.04 g and equilibrium time of 3 h when the 0.05 wt.% of CaCO3 nanoparticles were incorporated. The adsorption kinetics could be described using pseudo-second-order with R2 values of higher than 0.99 since the adsorption process is governed by chemisorption. The maxi-mum adsorption capacity of PCBs with 0.05 wt.% of CaCO3 nanoparticles loading determined by pseudo-second-order was 49.02 mg/g. After six cycles of adsorption-desorption processes, about 50% of the dye can still be adsorbed.