Forward osmosis desalination of brackish groundwater in Egypt under the framework of water -energy-food Nexus

This research investigates the application of Fertilizer Drawn Forward Osmosis FDFO technique and its potential use in Egypt under the Framework of the Water-Energy-Food Nexus. Fertilizers Drawn Forward Osmosis Desalination Technique has been proven to be a great exhibition of tackling one of the sustainability challenges from Water –Energy-Food Nexus perspective. Being an energy efficient technology, it offers a technical solution to provide alternative water supply without compromising energy consumption, moreover the product water quality is adequate for agriculture and crop production. In this work, feed solution used is real brackish groundwater extracted from a well in Sinai, Egypt. Two sets of experiments have been conducted in order to assess in selecting the proper scenario for the crop producer. The first set examined three commonly used single fertilizers in Egypt: Potassium Nitrate, Di-Ammonium Phosphate and Urea to compare between their performances. The second set examined standard hydroponic recipe, which is a mixture of nutrients, as a draw solution to fertilize crops in hydroponics systems. The nutrients mixture performance has been tested and compared to that of the individual components at the same concentrations in order to assess how mixing nutrients influence their performance. Regarding the first set, Di- Ammonium Phosphate resulted in the best performance as draw solute among the three tested draw solutes, where it has exhibited a significant water flux equivalent to 13.8 (Liter per membrane unit area per hour lm-2h-1 and always referred to as LMH, a feed ions rejection reaching 98% and acceptable concentrations of draw solute ions in the final product water. For the Second set, The Hydroponics nutrients mixture have exhibited better performance as draw solution compared to their individual macro-components. The use of the nutrient mixture as draw solute resulted in a flux of 11.7 LMH, 95% feed ions rejection compared to 9.2 LMH, 91%, and 10.03 LMH, 93% for its individual components. Mixing nutrients boosted the osmotic pressure and enhanced the driving force for fresh water permeation. Hence, it can be concluded that mixed nutrients have better performance than single fertilizers, not only for the enhanced desalination features and for water extraction performance, but also because they provide a complete set of nutrients necessary for growing crops.