Batch and continuous fixed-bed column adsorption of Cd(II) from aqueous solution and industrial effluent by functionalized nano-structured cellulose particles

Adsorption of cadmium (II) has been investigated on phosphorylated and functionalized nano-celluloses (azeh2, azeh10 and azeh-TDI). The results demonstrated the capacity of the nanoparticles to reduce Cd(II) in aqueous solution. The performance of the nanocellulose varied accordingly azeh2 > azeh-TDI > azeh10. 53%-99% removal ratio was achieved and adsorption was pH dependent with the best performance of 0.4 g/L. The sorption process was exothermic for azeh2 and azeh10 whereas it was endothermic for azeh-TDI sample. Sorption of Cd(II) was best fitted by the pseudo-second-order kinetics model. Low ionic strength favoured the adsorption of Cd(II), with the best desorption of metal-loaded cellulose nanoparticles achieved at high concentration of HNO3. Desorption kinetics data fitted the Elovich kinetics. Fixed-bed column adsorption of Cd(II) demonstrated the ability of the nanocelluloses to adsorbed Cd(II) in the effluent from the nail and roofing sheet making industry. The 6 cm bed depth adsorbed 0.019-2.740 mg/g of Cd(II) while 8 cm bed depth adsorbed 0.016-2.301 mg/g of Cd(II), respectively. Sorption kinetics was Thomas and Yoon-Nelson model. Packed column reduced 2,000 to 30 cfu/mL microbial contaminants after 24 h of treatment in the column. The nanocelluloses are promising bioadsorbent for treatment of water/wastewater system laden with metals and microbes.