TY - JOUR
T1 - Removal of aluminium, arsenic, and zinc using rice husk ash geopolymer
AU - Bopape, Prince Immanent
AU - Modley, Lee Ann S.
AU - Falayi, Thabo
AU - Sithole, Thandiwe Nastassia
N1 - Publisher Copyright:
Copyright © 2025. Published by Elsevier B.V.
PY - 2026/2
Y1 - 2026/2
N2 - This study investigated the potential of rice husk ash (RHA)-derived geopolymer as an adsorbent for removing heavy metals aluminium (Al), arsenic (As), and zinc (Zn) from wastewater. The Response Surface Methodology (RSM) and Random Forest (RF) modelling were used for modelling the adsorption process. The RHA gepolymer was characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Brunauer-Emmett-Teller (BET) analysis. The adsorption could be modelled using Langmuir isotherm and pseudo first order kinetic equation. The geopolymer achieved a 96–99%, 85–92% and (94–98%) removal Al, As and Zn respectively. The BET analysis showed the geopolymer was a mesoporous adsorbent with capillary condensation favouring type IV isotherm adsorption. The desirability studies showed that temperatures below 300C and adsorbent loading around 5% m/v were ideal for the removal of As and Al whilst Zn demonstrated an increase in removal efficiency with an increase in temperature. Extended adsorption time above 8 hrs led to desorption of heavy metals. The adsorption was endothermic and the mechanism of sorption was physisorption.
AB - This study investigated the potential of rice husk ash (RHA)-derived geopolymer as an adsorbent for removing heavy metals aluminium (Al), arsenic (As), and zinc (Zn) from wastewater. The Response Surface Methodology (RSM) and Random Forest (RF) modelling were used for modelling the adsorption process. The RHA gepolymer was characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Brunauer-Emmett-Teller (BET) analysis. The adsorption could be modelled using Langmuir isotherm and pseudo first order kinetic equation. The geopolymer achieved a 96–99%, 85–92% and (94–98%) removal Al, As and Zn respectively. The BET analysis showed the geopolymer was a mesoporous adsorbent with capillary condensation favouring type IV isotherm adsorption. The desirability studies showed that temperatures below 300C and adsorbent loading around 5% m/v were ideal for the removal of As and Al whilst Zn demonstrated an increase in removal efficiency with an increase in temperature. Extended adsorption time above 8 hrs led to desorption of heavy metals. The adsorption was endothermic and the mechanism of sorption was physisorption.
KW - Adsorption Desirability
KW - Geopolymers
KW - Random Forest model
KW - Response Surface Methodology
KW - Rice Husk Ash geopolymer
KW - Wastewater Treatment
UR - https://www.scopus.com/pages/publications/105025457638
U2 - 10.1016/j.rechem.2025.102984
DO - 10.1016/j.rechem.2025.102984
M3 - Article
AN - SCOPUS:105025457638
SN - 2211-7156
VL - 20
JO - Results in Chemistry
JF - Results in Chemistry
M1 - 102984
ER -