Simultaneous oxidation and esterification of cellulose for use in treatment of water containing Cu(II) ions.

Cellulose powder was modified with Sodium Hypochlorite (NaOCl) and Octenyl Succinic Anhydride (OSA) in different proportions. The adsorbents were characterised by BET, FTIR, XRD, TGA and SEM. Intrinsic viscosity increased with degree of substitution (DS). FTIR peaks confirmed the presence of carbonyl groups. Batch adsorption parameters studied were contact time, adsorbent dosage, pH and temperature. Adsorption process was influenced significantly by pH. Freundlich isotherm showed a better correlation coefficient (R2 and χ2) than Langmuir and Temkin isotherms. The adsorption process was inferred as physico-chemical adsorption process (based on isotherm and kinetic modelling). Pseudo second order kinetics model was found to fit well on the empirical data obtained. Adsorption of Cu(II) ions over the modified cellulose was found to be exothermic in nature (ΔH<0). HCl was found to be more effective desorbing agent than NaOH.