Cellulose is the most abundant polysaccharide in nature and it encompasses a lot of industrial applications; it is from totally renewable resources and it reduces the greenhouse effect. The cotton yarn has an unavoidable loss of 8 % during any textile factory processes. Due to its intrinsic cellulosic nature, this cotton dust waste may be a convenient feedstock for chemical derivatization with diethylaminoethyl groups, thus providing a DEAE(+)-CDW anionic exchange matrix able to adsorb a residual dye, such as Reactive Red 239 (RR239), from textile wastewaters. A factorial design (with such parameters as alkali catalyst and derivatization reagent) and other experiments were performed to investigate the influence of the initial model dye concentration, contact time and presence of common textile salts. A selected DEAE(+)-CDW displayed RR239 dye sorption of 60.00 (column) and 93.41 mg g(-1) (batch). A good fit was found for the Langmuir isotherm (R (2) = 0.9878) drawn from the sorption data. The use of more DEAE(+) reagent in the synthesis step resulted in better DEAE(+)-CDW matrices, with the same being valid for the alkali concentration but with less intensity. The addition of 50 or 100 mmol L-1 NaCl increased RR239 retention by 8.15 %, and the enzymatic cellulolytic degradability of fully dyed DEAE(+)-CDW, compared to dye-free DEAE(+)-CDW, was reduced from 42.57 to 28.15 %. The data support the assumption that the DEAE(+)-CDW matrix is effective in the removal of the recalcitrant residual dye and or its colored degradation products still present in partially precleared textile waste sample and thus this represents an important alternative in the treatment of colored textile effluents. Shortly, a factory problem was converted in a solution for another greater environmental problem.