Improvement of the Adsorption Efficiency of Rice Husk Ash for Crystal Violet Dye Removal from Aqueous Medium

Document Type : Original Article


1 Department of Chemistry, Abdul Wali Khan University Mardan, 23200 Pakistan

2 Department of Chemistry, Abdul Wali Khan University Mardan, 23200 Pakistan.

3 Engineering Research Center for Functional Ceramics of the Ministry of Education, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, PR China.

4 Department of Chemistry, Woman University Swabi, Pakistan.

5 Department of Chemistry, Faculty of Science, Helwan University, Ain-Helwan, 11795 Cairo, Egypt.

6 - Chemistry Department, Faculty of Science, Assiut University, P.O. Box: 71515, Assiut, EgyptŲ² - Chemistry Department, College of Science, Jouf University, P.O. Box: 2014, Sakaka, Saudi Arabia


Rice husk ash (RHA) product was chemically modified and utilized for the adsorption of toxic dye from water. The textile dye (crystal violet) was removed from aqueous media using Rice Husk Ash (RHA) and Chemically Modified Rice Husk Ash (CMRHA) as adsorbents. The effects of stirring time, dye concentration, adsorbent dose, pH and temperature on the adsorption capacity were studied. The chemical modification of RHA enhanced the absorption efficiency from 88.9% to 99.1% at pH 6 and room temperature by using 2g/L of adsorbents. Thermodynamics study indicated that the process is exothermic and spontaneous. The kinetics study indicated that the adsorption process for the two adsorbents best fitted to the pseudo-second order kinetics model. The equilibrium data were tested with Langmuir, Freundlich, and Temkin equations. It was investigated that data best fitted to the Langmuir and Temkin models, which indicated for chemisorptions process and heterogeneous surface of the adsorbents.


Main Subjects

Volume 65, Issue 131 - Serial Number 13
Special Issue: Chemistry and Global Challenges (Part A)
December 2022
Pages 427-435
  • Receive Date: 19 February 2022
  • Revise Date: 20 March 2022
  • Accept Date: 03 April 2022