Forward osmosis (FO) is a membrane separation process using a highly concentrated draw solution with high osmotic potential to draw water across a semi-permeable membrane from a feed source. This feed source may be seawater, wastewater or other natural or contaminated water sources. Unlike other membrane driven purification processes, the product is not clean water, but a diluted draw solution. As a result a second step is often needed to produce a pure water product. A major advantage of FO is that the low hydrodynamic pressure involved leads to lowered fouling of membranes and greater flux recovery after cleaning, as well as often providing a low energy process which can recover clean water from difficult or highly fouling sources. Selection of an appropriate and effective draw solution is essential for the practical operation of an FO process. This review will give an overview of the theoretical underpinnings of draw solution performance and a comprehensive summary of the current literature regarding the different types of draw solutions which have been investigated and their respective benefits and detriments. Highlights  Literature on draw solutions used in forward osmosis processes reviewed including the state-of-the-art  Overview of theoretical underpinning of draw solution performance  Up to date developments of draw solutes  Comparison of draw solute recovery methods

Recently, Forward Osmosis (FO) desalination process has been widely investigated as a potential technology that could minimize the drawbacks of traditional desalination processes.To review the past, current, and future research scope of the FO desalination process, a statistical analysis that gives insights on the FO topics of interest is needed to assist researchers in the development of the FO technology. The main objective of this work is to conduct a Highlights 1-Research trends in forward osmosis technology in the last 20 years. 2-Most important research areas are fouling, draw solution, and membrane development.3-Increasing research activity is in organic matter treatment, recovery system of the DS and energy consumption. 4-The establishment of an energy-and cost-effective hybrid system is necessary to promote FO process.

The forward osmosis process has obtained renewed interest nowadays and it might become an alternative solution for many industrial applications to meet the current and future requirements for potable water. The FO process depends on the osmotic pressure gradient between a high salinity draw solute and low salinity feed solution across a semi-permeable membrane to extract pure water. Despite the potential advantages of FO, there are some technical drawbacks that hinder FO application for water desalination. One of the most significant critical challenges is the need for membrane compatible with the FO process. To improve FO desalination feasibility, membrane development is required to obtain maximum water permeability and minimum Highlights  Comprehensive overview of commercial FO membranes and modified FO sub-layers.  Discussion of fundamental and practical challenges of FO membrane performance.  Chemical modification strategies to minimize the structural parameter of FO sub-layer.

Membrane-based desalination technologies for agricultural applications are widely applied in many countries around the world. Sustainable and cost-effective desalination technologies, such as reverse osmosis (RO), membrane distillation, forward osmosis, membrane bioreactor, and electrodialysis, are available to provide treated water, but the pure water product does not 1 Introduction 5-8 2 Applicability of membrane desalination technologies for fertigation 8-10 3 Water quality required for agricultural irrigation 10-12 4 Challenges in membrane technologies development 12-15 Water nutrient production from seawater/brackish water 15-28 5.1 Pressure-driven membrane process 15-19 5.1.1 RO process 15-17 5.1.2 NF process 17-19 5.1.3 FO process 19-22 5.2 Chemical-driven membrane process 23-28 5.2.1 Electrodialysis (ED) process 23-25 5.2.2 Capacitive Deionization (CDI) process 25-28 6 Water nutrient production from industrial wastewater 28-39 6.1 Pressure-driven membrane process 28-31 6.2 FO process 31-34 6.3 Temperature-driven membrane system 34-36 6.4 Membrane bioreactor (MBRs) process 36-39 7 Application of hybrid systems for agriculture 39-58

Transparent titania coatings have self-cleaning and anti-reflection properties (AR) that are of great importance to minimize soiling effect on photovoltaic modules. In this work, TiO2 nanocolloids prepared by polyol reduction method were successfully used as coating thin films onto borosilicate glass substrates via adsorptive self-assembly process. The nanocolloids were characterized by transmission electron microscopy and x-ray diffraction. The average particle size was around 2.6 nm. The films which have an average thickness of 76.2 nm and refractive index of 1.51 showed distinctive anti soiling properties under desert environment. The film surface topography, uniformity, wettability, thickness and refractive index were characterized using x-ray diffraction, atomic force microscopy, scanning electron microscopy, water contact angle measurements and ellipsometry. The self-cleaning properties were investigated by optical microscopy and UV-Vis spectroscopy. The optical images show 56% reduction of dust deposition rate over the coated surfaces compared with bare glass substrates after 7 days of soiling. The transmission optical spectra of these films collected at normal incidence angle show high anti-reflection properties with the coated substrates having transmission loss of less than 6% compared to bare clean glass.