by Takwa Tabbassi  , Asma Abdedayem  , Zohra Sghaier  , Amor Hafiane  and Mustapha Hidouri

Received: 15 December 2025;  Published: 10 April 2026;  doi: 10.21926/aeer.2602006

This study investigated the use of new bioadsorbent the Hydroxyfluorapatite (Ca10(PO4)6OH1.75F0.25, HFA) to eliminate Alizarin Red S (ARS), a harmful water pollutant. Initial batch tests were conducted to evaluate the adsorption process, focusing on both kinetics and equilibrium behavior. Various kinetic models were applied such as: pseudo first-order, pseudo second order, the intraparticular diffuision model and external diffusion model. The modeling results proved that the pseudo-second-order model best matched t [...]

by Aster Woldu Gebrearegay  , Melaku Tesfaye  and Alemu Gizaw

Received: 04 January 2026;  Published: 24 April 2026;  doi: 10.21926/aeer.2602007

Hexavalent chromium (Cr(VI)) is a carcinogenic pollutant commonly found in wastewater from tanning and electroplating industries. This study investigates the efficiency of raw Cordia africana sawdust as a biosorbent for Cr(VI) removal. Batch adsorption experiments were conducted by varying pH (3-8), contact time (10-120 min), and Cr(VI) concentration (21-47 mg/L) using Response Surface Methodology (RSM) with Box-Behnken design. Characterization was performed using FTIR, SEM, BET, pH, and PZC analysis before and aft [...]