randomness occurred at solid/solution interface during the adsorp-tion process [27].
4. Conclusions
This paper had demonstrated that PK-AC was an effective adsor-bent for removal of RhB from aqueous solution. Both a low initial RhB concentration and a high temperature were benefit to RhB adsorption. pH value of solution only had a little effect on adsorp-tion. Kinetics studies suggested that the adsorption mechanism of RhB followed the pseudo-second model well. Intra-particle dif-fusion was not the only rate controlling step. The equilibrium analysis reflected that the Langmuir model fitted isotherm date well. Furthermore, thermodynamic studies had demonstrated that this adsorption process was spontaneous, favorable and end other-mic. Therefore, it can be concluded that the treated rice husk-based activated carbon was a promising adsorbent.