Hybrid coagulants, aluminium sulphate-Aloe vera (ALAV) and magnesium sulphate-Aloe vera (MGAV) were prepared for the
primary treatment of methylene blue (MB) dye wastewater treatment through coagulation-flocculation process. The effects of the
independent factors and their interaction on the dye removal (%) were determined using two independent factors, i.e. pH and
dosage based on 22 full factorial design. All the independent factors and their interaction were significant in removing dye. The
dye removal (%) for both ALAV and MGAV were then optimized through central composite design. ALAV was able to remove
50–55% of dye while MGAV was able to remove 60-70% of dye. Therefore, MGAV was proven to be a more effective hybrid
coagulant in removing dye.