Pressure driven membrane process such as reverse osmosis (RO) and nanofiltration (NF) have been used in the past few decades for the treatment of water. These two treatments affectively remove the organic, biological, and inorganic contaminants from water 13 14. In RO/FO membranes’ fouling is also inevitable due to presence of different kind of containments in feed water 15. Several studies were published on the rejection mechanism of pharmaceutically active compounds (PhACs) in NF/RO membranes 16 17 18 19 20. Many researchers focused on membrane fouling during pharmaceuticals rejection in the membrane process 21 22 23 24. Some research work is also published on combined fouling study in the treatment process to investigate the combined effects of foulants in fouling 25 26 27. Combine influence of natural organic matter (NOM) and colloidal particles in nanofiltration membrane fouling also published 28. Both NF/RO membranes are used for the removal of pharmaceuticals from water. Research of combine fouling study during pharmaceutically active compounds (PhACs) removal is available 29 but its only limited to nanofiltration (NF) membrane. No study is available on combine fouling effect of organic matter and colloids (silica colloid) in pharmaceuticals rejection by using RO membrane. Thus aim of this research proposal is to study the implications of combine fouling (organic +colloidal) in RO membrane during pharmaceutically active compounds (PhACs) rejection.