Cationized sawdust as ion exchanger for anionic residual dyes

Abstract

Using the same procedure as recently described for cotton fiber, the preparation of cationized wood sawdust was performed by treating alkali sawdust with epoxy propyl trimethyl ammonium chloride (EPTMAC) in a nonaqueous medium (dimethylformamide, DMF). The fixation of ammonium groups onto sawdust was monitored by weight uptake, nitrogen content determination, and infrared spectroscopy. EPT-MAC-sawdust with a 0.5 wt % nitrogen content is then used as adsorbent for acid dyes (Acid Blue 25, Acid Yellow 99, Reactive Yellow 23, and Acid Blue 74). The adsorption capacity, determined by spectrometric measurement of the residual dye in the treated solution, decreases with increasing temperature. The modeling of the adsorption isotherms using Langmuir, Freundlich, and General relations allows the determination of isotherm constants. Globally, EPTMAC-sawdust has a behavior similar to EPTMACcotton, and its use for depollution of waste waters from dyeing industries presents advantages over cotton, such as a larger availability and a lower price.

Cationized Lignocelluloses as Scavengers for Anionic Surfactants. II. Hydrophobic Interactions

“…In contrast, however, internal cationic sites (and, in particular, those occurring in the bulk of the amorphous zones of the cellulosic sorbent) cannot adsorb the same number of surfactant molecules due to the size of the resulting hemi-micelle. A similar observation was made previously with respect to dye molecules adsorbed on the same cationized sorbents (Baouab et al 2000(Baouab et al , 2001: the large dye molecules were incapable of saturating all the cationic sites anchored on to the sorbent. As a consequence, the surface cationic sites must involve hemi-micelles with a higher number of surfactant molecules, so that the reported value of 4.5 for SDS onto polystyrene (Zhu et al 1989) would also appear reasonable in the present case.…”

“…However, with DBS, the value of ca. 1.8 obtained was lower as might be expected from the lower aggregation number, n, for its micelles, with a value of 27 having been reported (Bi et al 2001) compared to 69 for SDS (Shah et al 2001).…”

“…et al (2003) studied such competition for the first step using identical quantities of each surfactant in solution, but with the total quantity of surfactant being twice the adsorption capacity. The predominance of DBS (58.6%) over SDS (41.4%) observed was attributed to the higher hydrophobicity of DBS (Garcia-Delgado et al 1992). This tendency was inverted in the second step: increasing quantities Q i of the stoichiometric binary surfactant mixture (Q i = 2-4C a ) led to increasing proportions of SDS in the second layer as a result of its better self-aggregation relative to DBS.…”

[Dye molecules/copper(II)/macroporous glutaraldehyde‐chitosan] microspheres complex: Surface characterization, kinetic, and thermodynamic investigations

“…Cellulose derivatives have been particularly investigated during the treatment of effluents. [33][34][35] In a previous work, Baouab et al, 7 have chemically modified the cotton fiber by ethylene diamine and then the ethylene diamine-grafted groups immobilizes Cu(II) ions was tested for the adsorption of Calma and AB25 as ligands in the metal-coordinating process. The objectives of this article concern the description, for the first time, of the feasibility and the characterization of a ternary complex formation between the two model ligands (AB25 and Calma), Cu (II) ions, and crosslinked chitosan microspheres using a batch process under several experimental conditions.…”

Cationized milled pine bark as an adsorbent for orthophosphate anions

“…11,26,27 Gruber et al 28 examined new approaches for attaching quaternary ammonium groups to cellulose and demonstrated that the use of oligoionomers results in very high cationic densities on the fiber surfaces.…”