Accepted Manuscript Molecular mechanism of anionic dyes adsorption on cationized

ACCEPTED MANUSCRIPT
24 
process. It is consistent with the conclusion of kinetic analysis. 
Table 6 Thermodynamic parameters for adsorption of Diamine Green B (DG-B), Acid 
Black 24 (AB-24) and Congo red (CR) onto CRHC. 
Dyes 
ΔH
0 
(kJ/mol) 
ΔS
0
[J/(mol•K)] 
ΔG
0
(kJ/mol) 
303.15 K 
313.15 K 
323.15 K 
DG-B 
15.06 
35.11 
-4.39 
-3.98 
-3.46 
AB-24 
16.32 
43.52 
-3.10 
-2.65 
-2.89 
CR 
2.96 
19.57 
-2.98 
-3.15 
-3.37 
4. Conclusions 
Cationized rice husks cellulose (CRHC) was prepared via grafting with 
quaternary ammonium functional group using N, N-dimethyl-1-octadecylamine as 
modified agent. Structural and morphological characterizations were performed using 
FTIR, XRD and SEM analysis. The characterization results showed that the molecular 
structure and morphology of RHC have changed and the quaternary ammonium group 
was successfully grafted onto the molecular structure of RHC. The possible 
adsorption mechanism for DG-B, AB-24 and CR adsorbed onto CRHC might be due 
to the combination of molecular structural characteristics of the adsorbent and 
adsorbate, electrostatic attraction, hydrogen bonding and the competition of OH
−
ions. 
CRHC has a good reusability and high adsorption performance for dye removal. The 
non-linear kinetics and isotherms fitting results shows that Pseudo-second-order and 
Langmuir models are more suitable for describing the adsorption properties of DG-B, 
AB-24 and CR adsorbed onto CRHC. The adsorption is a spontaneous and feasible 
purification process, and increasing the temperature is conducive to the adsorption 
process. 

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