Recycling of brine of RO system with environmental friendly nano-materials for irrigation

Water desalination using the RO system is expanding. Due to large volume of brine in the treatment system, its recycling for irrigation can be an effective step in sustainable development of environment. In this study, treatment of RO brine was performed in three phases; with graphene oxide solution, with graphene oxide sludge, with graphene oxide solution and then graphene oxide sludge. The results showed percentage decrease of electrical conductivity of brine with graphene oxide solution was equal to %48.84 (decrease from 12000µs/cm to 6139µs/cm), with graphene oxide sludge equal to %10 (decrease from 12000µs/cm to 10800µs/cm), with graphene oxide solution and then graphene oxide sludge %51.9 (decrease from 12000µs/cm to 5772µs/cm). pH of treated brine with graphene oxide was constant with little change or no change. The results were in accordance with water quality guideline and standard of Iran country for irrigation. The advantages of this method of treatment were ease and speed of work in a short time up to maximum 10 minutes. Graphene oxide sludge was thicker and less, compared with sludge in most conventional water treatment processes. Due to the carbon structure of the resulting sludge, it can be dried and then it can be disposed in environment. Based on the results, it seems the new treatment method of brine with graphene oxide can be used for RO systems as an environmental-friendly method.