Citric acid modified cellulose: a cost effective adsorbent for the immobilization of Cr (III) ions from the aqueous phase

Chromium is listed among toxic metals known to cause serious health damage to humans and other living forms alike. Effluent discharged from tanneries and textile relating industries are some of the major contributors of chromium (III) ions in the surrounding. Here is presented a new, simple, and cost-benefit approach to the remediation of Cr (III) ions by citric acid modified cellulose. Cellulose was initially activated using 20% NaOH followed by a thermochemical treatment with citric acid to produce the modified product (modified cellulose). FTIR analysis confirmed the formation of the product by the presence of the peak at 1739 cm−1. Subsequent use of the modified product successfully removed 81.3% of Cr (III) ions from the aqueous phase under the optimized conditions. Whereas, kinetic, isotherm and thermodynamic studies revealed that that the process followed the second-order kinetic, Langmuir model, and was exothermic respectively. The cost for the immobilization of Cr (III) ions from aqueous phase may range between $10 – $50 per million liters, which is much more economical than previously reported methods. In conclusion, citric acid modified cellulose with high affinity toward the Cr (III) ions can be implemented as a green-based approach at large-scale for cleaning industrial effluents.