[show abstract][hide abstract] ABSTRACT: In order to improve the adsorption capacity of chitosan (CTS) for methylene blue (MB) cationic dye, a series of N,O-carboxymethyl-chitosans (N,O-CMCTS) were prepared under heterogeneous conditions by controlling the reaction time. The adsorption of MB from aqueous solution
onto N,O-CMCTS was studied. The effects of degree of substitution (DS) of N,O-CMCTS, initial pH of the dye solution and adsorption temperature were investigated in detail. The results showed that the
adsorption capacities of N,O-CMCTS increased with the increase of DS and N,O-CMCTS with DS of 0.72 exhibited the highest adsorption capacity (349mg/g). The adsorption kinetics of N,O-CMCTS was found to follow the pseudo-second-order model. The adsorption equilibrium of N,O-CMCTS fitted very well with the Langmuir isotherm model, showing maximum monolayer adsorption capacity of 351mg/g. The adsorption
mechanism of N,O-CMCTS was also discussed by means of FTIR spectra and XPS. The results revealed that the –OH, –NH2, and –COOH groups of N,O-CMCTS were involved in the adsorption process. The desorption studies showed that N,O-CMCTS could be regenerated and used for the adsorption of MB repeatedly.
[show abstract][hide abstract] ABSTRACT: N-succinyl-chitosan-g-polyacrylamide/attapulgite (NSC-g-PAM/APT) composite was applied as adsorbent for the removal of methylene blue (MB) from aqueous solution. The initial pH
value of the dye solutions, the contact temperature, the contact time and the concentration of the dye solutions on adsorption
capacity of the composite for MB dye were investigated. The adsorption kinetics and isotherms were also studied. It was shown
that all the sorption processes were better fitted by pseudo-second-order equation and the Langmuir equation. The results
indicated that the adsorption capacity of the composite was higher than those of chitosan (CTS) and attapulgite (APT). The
desorption studies revealed that the composite provided the potential for regeneration and reuse after MB dye adsorption,
which implied that the composite could be used as quite effective adsorbent for the removal of MB from aqueous solution.
Key wordsN-succinyl-chitosan–Attapulgite–Composite–Adsorption–Methylene Blue
Korean Journal of Chemical Engineering 28(8):1658-1664. · 1.06 Impact Factor