Scaling and Fouling of Reverse Osmosis (RO) Membrane: Technical Review

Abstract

An estimated 1.2 billion inhabitants are still faced with the water crises worldwide and the number keeps increasing. The population growth, rising standards of living, industrial proliferation, water source contamination and climate change remains one of the contributing factors to water scarcity. The use of reverse osmosis technology to desalinate brackish and sea water is one of the key reliable sources of alternatives water supply. However, the technology is subjected to scaling and fouling challenges. Fouling and scaling are regarded as major cost intensive trials in the RO desalination industry. Scaling is mostly stirred by the precipitation of calcium carbonates, calcium sulphates, barium sulphate and silicates on the RO membranes which clogs the membrane pores whereas, fouling is by the deposition of suspended matters, colloids and micro-organisms on the membrane. Even though there are several methodologies developed to control scaling and fouling, the feed water composition, pre-treatment, temperature, chemical composition and filtration process prior to RO membrane filtration remains different from plant to plant, making it almost impossible to predict, mitigate or control fouling and scaling.