Dye removal reached up to 99% under optimum concentration; i.e., in terms of the
acidic solutions and the stoichiometric ratio between the amine groups of the biopolymer and the
sulfonic groups in the dye. The flocs were recovered and the dye was efficiently removed using alkaline
solutions (0.001–1 M NaOH solutions) and the biopolymer, re-dissolved in acetic acid solution, was
reused in a further treatment cycle.