CARBOXYLATED CELLULOSE NANOFIBERS AS A NOVEL EFFICIENT ADSORBENT FOR WATER PURIFICATION

Cellulose nanofibers (CNF) containing carboxylic groups were prepared through sequence oxidation steps. TEMPO-periodate-chlorite oxidation steps of bleached cellulose pulp, extracted from bagasse, were carried out. The carboxyl content measurements revealed that, mostly, cellulose nanofibers with tricarboxylic groups for each anhydroglucose unit were formed (3.5 mmol g(-1)). The highly carboxylated CNF (TPC-CNF) were studied by FTIR, AFM, SEM and TEM techniques. TPC-CNFs were examined to eliminate methylene blue (MB) from synthetic solutions and compared with TEMPO-oxidized CNF (T-CNF). The best interpretation of the adsorption results was given by the pseudo-first order and Langmuir isotherm models, with maximum adsorption capacity of 502 mg/g, compared to conventional T-CNF, which reached 409 mg/g. TPC-CNF displayed high adsorption capacity in a slightly basic medium. This article presents a novel biodegradable and sustainable adsorbent for organic dye removal.