Abstract

A series of amine-terminated dendritic polymers (ADPs) were synthesized by stepwise substitution reaction and were used as an adsorbent for removal of acid black dye NT from aqueous solution. Comparison experiments showed that the ADP-3 has good adsorption effect. Then, the effects of various parameters such as initial acid black dye NT concentration (50-300mg/L) and solution pH(1.5- 6.5) were investigated. The point of zero charge (PZC) of ADP-3 has been determined. Specific surface area and average adsorption pore size of the ADP-3 were 21.378m2/g and 3.833nm, respectively. Field scanning electron microscopy (FESEM) indicated that the adsorption material has porous structure, which provided favorable conditions for adsorption process. The experimental data were analyzed by Langmuir and Freundlich models of adsorption. Equilibrium data were fitted well with the Freundlich model. Thermodynamics parameters, ΔG, ΔH and ΔS indicate that the adsorption of acid black dye NT onto ADPs were spontaneous and endothermic process in nature. Pseudo-first-order and pseudo-second-order kinetic models were used to fit the adsorption kinetic data. The adsorption kinetics was found to follow the pseudo-first-order kinetic model. Amino blocking indicated that the amino content plays an important role in the adsorption process. The adsorbent was also applied to the treatment of leather dye effluent, the results showed that ADP-3 exhibit a prominent adsorption property on leather dye effluent.