Preparation and metal uptake studies of modified forms of chitin.

Chitin (C), a biopolymer which showed moderate sorption capacity (SC) towards Cu(II) and Fe(III) was suitably modified to enhance the SC. Three types of modifications viz., protonated chitin (PC), carboxylated chitin (CC) and grafted chitin (GC) were carried out to increase the SC. The modified forms of chitin showed enhanced SC for both Cu(II) and Fe(III) than the raw chitin. These sorbents were characterized by the FTIR and SEM with EDAX analysis. The various influencing parameters viz., contact time, pH and the interference of common anions during the sorption have been investigated. The sorption data was reasonably explained using Freundlich and Langmuir isotherms. The calculated values of thermodynamic parameters indicated that, the sorption is spontaneous and endothermic in nature. The order of selectivity of Cu(II) and Fe(III) on modified chitin was found to be Fe(III)>Cu(II). The suitability of modified chitin has been tested with the field samples collected in a near by industrial area. The suitable mechanism for the respective metal removal has been established.