Evaluation of ethylenediamine-modified nanofibrillated cellulose/chitosan composites on adsorption of cationic and anionic dyes from aqueous solution

•The NFC/CS was prepared by coating chitosan on nanofibrillated cellulose.•An adsorbent was prepared by modifying the NFC/CS with ethylenediamine (E-NFC/CS).•The E-NFC/CS composites can be used to adsorb both cationic and anionic dyes. A multi-functional adsorbent was prepared by modifying nanofibrillated cellulose/chitosan composites with ethylenediamine (E-NFC/CS). The E-NFC/CS was characterized by FTIR and used for adsorption of cationic dye methylene blue (MB) and anionic dye new coccine (NC) from aqueous solution. The FTIR results showed that the E-NFC/CS contained more amino groups than the NFC/CS due to the modification for the NFC/CS with ethylenediamine. The results indicated that the maximum adsorption capacities occurred at pH 4.0 for MB and pH 2.0 for NC, respectively. The adsorption equilibrium time for MB and NC was 30 and 50min, respectively. In addition, the regenerated E-NFC/CS exhibited excellent adsorption performance for NC. It can keep almost 98% of the adsorption capacity after reused three times. Therefore, the E-NFC/CS can be potentially used as an effective adsorbent of cationic and anionic dyes in industrial effluents.