Membrane autopsy study to characterize fouling type of RO membrane used in an industrial zone wastewater reuse plant

Abstract

In recent years, it has become very important to reuse wastewater as an alternative water source in industrial zones. Reverse osmosis (RO) membranes are the most used membrane technology for wastewater reuse due to their remarkable divalent and monovalent ions removal efficiencies. However, membrane fouling is a serious problem in RO plants which hinders the membrane performance and shortens the membrane lifespan. In this study, a detailed membrane autopsy study was carried out in fouled RO membrane to characterize the type of membrane fouling obtained from a full-scale industrial zone wastewater reuse plant in Turkey. The autopsy analysis results of the fouled membrane showed that the membrane surface was covered dominantly by inorganic scaling of CaCO3. Also, there was a remarkable amount of molybdenum (Mo) element on the membrane surface which was attributed to wastewater discharges of automotive industries. Lastly, an appropriate chemical cleaning protocol was proposed. More effective membrane cleaning efficiency was achieved for more acidic agents which was attributed to the presence of inorganic fouling. This study helps to understand the possible fouling formations on the membrane surface used in industrial zone wastewater reuse plants and gives an idea to take necessary precautions for fouling control strategies.