Title
Valorization of TEMPO-oxidized cellulosic fractions for efficient dye removal from wastewaters
Authors
GABRIELA BILIUTA DANIELA SUTEU TEODOR MALUTAN ANDREEA-IRINA CHIRCULESCU IULIA NICA and SERGIU COSERI

Received Dedicated to Acad. Bogdan C. Simionescu on the occasion of his 70^th anniversary
Published Volume 52 Issue 7-8 July-August
Keywords cellulose sorbent, aqueous medium, operating variables, reactive dye, sorption

Abstract
Never-dried softwood bleached sulfite pulp (SBS) was oxidized employing a TEMPO-mediated protocol to introduce carboxylic groups. The content of the negatively charged groups was determined by potentiometric titration and thoroughly characterized. Never-dried oxidized cellulose (SBSox) was tested as potential sorbent for the reactive dye Brilliant Red HE-3B. Several parameters, including initial pH of the solution, sorbent dose, dye concentration, temperature and contact time, were evaluated. The values of these parameters were found to depend significantly on the behavior of the cellulose material studied under the specified experimental conditions and less on the dye behavior. The maximum values of dye percentage removal were obtained at pH = 1.3, cellulose dose of 2 g/L, dye initial concentration of 36-240 mg/L, temperatures around 20-25 °C, and equilibrium time around 400 min. Based on the experimental results, the oxidized cellulose material can be successfully used as sorbent for dye removal from colored wastewaters.