Abstract
The present study assesses the application of the forward osmosis process using a thermolytic draw solution for irrigation water supply. A novel forward osmosis desalination process with thermal depression regeneration for producing high quality irrigation water is also proposed aiming to provide a reliable and cost-effective method in terms of specific energy consumption. The modified forward osmosis process proposed in this chapter has the potential to provide low-energy production of fresh water from seawater and wastewater, therefore leading to a substantial cost reduction. The specific energy consumption was calculated at the optimum operating conditions of the forward osmosis membrane system producing 1 m3/h of fresh water from seawater at a recovery rate of 50%. The estimated specific energy consumption was 2.7 kWh/m3 and could be decreased when a heat recovery process was used. Furthermore, the combination of the proposed process with a salinity gradient solar pond was evaluated, which resulted in a major reduction of the specific energy consumption to 0.25 kWh/m3. This method can provide a financially viable and sustainable cycle for seawater desalination, particularly in areas of high solar irradiance.