The temperature and pH did not affect the adsorption equilibrium time. An obvious increase of adsorption capacity can be observed as the temperature increased from 293 to 303 K (Fig. 3b).The adsorption capacity only presented a small increase with further increasing the temperature from 303 to 323 K. The above results reflected that the adsorption of RhB onto PK-AC was an endothermic process. The high temperature allowed a better mobility of RhB molecules, and was benefit to the adsorption.