This study reports the manufacture of polyethersulfone (PES) membranes using silica extracted from rice husk ash. The membrane was made using the non-solvent induced phase separation (NIPS) method by polymer blending. The effect of increasing silica concentration (0.5% - 3.0%) was investigated to obtain a membrane with better performance and antifouling properties. The resulting membranes were characterized by evaluating functional groups (FTIR), morphological structure (SEM), and membrane porosity tests. It was found that the silica additive had a positive effect on the prepared PES membranes. There was a change in the structure of the membrane morphology as evidenced by the SEM image on the cross-section of the membrane. Increasing the concentration of added silica, resulted in an increase in the porosity of the modified membrane. The results showed that the optimum pure water flux was obtained with the addition of 2.5% silica, which was 119.7 L/m2.hour with the humic acid rejection of 60.5% with better anti-fouling properties than the PES membrane without modification. [ABSTRACT FROM AUTHOR]