Removal Of Crystal Violet From Wastewater Using Different Chitosans And Cross-linked Derivatives
Free (open access)
495 - 504
P. Jassal, V. Raut
The crab shell chitosan (CSC) and the medium molecular weight chitosan (MMWC) beads are cross-linked with ethylene glycol diglycidyl ether (EGDE) solution to get EGDE-CSC and EGDE-MMWC beads. The adsorption of CSC and MMWC beads at pH 2–4 show the adsorption of crystal violet (CV) was not significantly affected. Langmuir’ isotherm study provides an equilibrium parameter RL, from the linear plots of Ce/X versus Ce for the adsorption of CV dye on MMWC beads and CSC beads. The adsorption is favourable if RL lies within the range, i.e. 0<RL<1. The TGA plots were performed on CV dye, and CV was absorbed on the MMWC powder, MMWC bead, and the EGDE-MMWC beads. Degradation takes place in two steps. The thermogravimetric analysis (TGA) of CV absorbed on MMWC, cross-linked with EGDE show that there is a decrease in the thermal stability of the cross-linked chitosans. Fourier Transform Infrared Spectrometer (FT-IR) gives a band at 1586 cm−1 for –N(CH3)2 and aromatic ring stretching (-C=C-) clear band at 1363 cm.−1 for CV. The IR of pure chitosan shows a broad band at 3433 cm−1 due to –NH2 stretching and –OH stretching at 1640 cm−1 and the band between 720 and 590 cm−1 shows –OH out-of-plane bend. The CV absorbed on CSC at different time intervals, MMWC powder, beads and 10–20% cross-linked EGDE-MMWC has also been studied.
equilibrium parameter RL, thermal stability, cross-linked chitosans, Langmuir’ isotherm