ABSTRACT
Reverse Osmosis (RO) is an advanced membrane technique used as a unique tool to treat water from different sources as well as to recycle and reclaim wastewater; –due to its efficiency it gives way to reject various water contaminants. Meanwhile, membrane systems when applied into practice suffer certain operational problems (such as high chemical and power consumption, pretreatment costs and large effluent disposal) that could be attributed to membrane fouling and measures to prevent it. One of the major problems of RO is formation of calcium carbonate and calcium sulfate dihydrate scales during RO plant operation. To prevent scaling on membrane surface the inhibitor dosing is widely used in RO desalination. These chemicals are commonly based on phosphonic or phosphoric acid that remains in the rejected stream (the reverse osmosis concentrate) and are discharged into surface reservoirs, which creates a serious environmental problem associated with eutrophication (Lattemann & Höpner 2008; Feiner et al. 2015).
