Preparation of a bagasse‐based anion exchange fiber for sugar decolorization

Sugar bagasse was converted into an anion‐exchanger through grafting acrylamide using (NH4)2Fe(SO4)2/H2O2 as initiator in an aqueous system, followed by reacting with ethylenediamine and hydrochloric acid. The effects of the grafting conditions such as monomer concentration, temperature, reaction time on the degree of grafting were investigated. The ion exchange capacity of the sugar bagasse base anion‐exchange fiber (SB‐IEF) was up to 3.70 mmol/g. Application of the SB‐IEF in sugar decolorization was evaluated. Compared with commercial strong basic anion exchange resin (AIER) and strong basic anion exchange fiber (AIEF), SB‐IEF showed the highest static decolorization capacity for sugar colorants (decolorization degree 71.40%), followed by AIEF (decolorization degree 68.74%) and AIER (decolorization degree 31.40%) at the same operating conditions. The dynamic decolorization results indicated that SB‐IEF showed larger processing volume than AIER and AIEF. SB‐IEF with higher grafting degree would have a higher decolorization degree. When 200 mL 2% brown granulated sugar solution was treated with 1 g SB‐IEF (grafting degree 82%), 80% decolorization degree could be achieved. The research results may provide a recyclable route for the comprehensive utilization of by‐products of sucrose industry.