In recent years, reverse osmosis water desalination has developed rapidly and has become the most competitive and widely used technology in the world. The number of desalination plants is increasing rapidly as freshwater needs increase. Various membrane technologies have been developed and improved, including nanofiltration (NF) and reverse osmosis (RO), whose desalination costs have been relatively reduced. Therefore, this work proposes an experimental study for a small desalination unit based on RO generated by renewable energy, which is mainly suitable for arid regions or desert areas that do not have electricity and water and can be applied for emergency treatment to meet strong freshwater resource needs. In this study, to meet the drinking water demand, a reverse osmosis desalination system is designed and evaluated in order to improve and optimize its operation. This system has a daily capacity of 2 m³. We used brackish groundwater, which has been characterized as reference water, to produce synthetic water for different salinities until seawater. The analysis is based on data obtained from experiments carried out in the standalone RO pilot designed for the production of fresh water. For this purpose, we conducted relevant experiments to examine the influence of applied pressure, salt concentration and temperature on the RO membrane performance. The effects of different factors that affect the energy consumption in the RO desalination process were analyzed, and those with significant influence were explored. The effectiveness of RO desalination coupled with a photovoltaic (PV) energy system is shown. We found the recovery rate for system operation to be 32%. An optimization study is presented for the operation of an autonomous RO desalination system powered by photovoltaic panels. The energy produced by the PV system was used to feed two pumps forthe production of drinking waterwithanRO membrane, under the conditions of the town of Bou-Ismail. As results, a 3 kWp PV system was installed based on the energy demand. The design data have shown that a 3 kWp PV system can power a 1.8 W RO load given the Bou-Ismail climate. Energy consumption in the case study under Bou-Ismail weather conditions were analyzed. The desalination of brackish water at a TDS value of 5 g/L requires an energy of about 1.5 kWh/m³. Using seawater at a TDS value of 35 g/L, this value increases to 5.6 kWh/m³. The results showed that the optimal recovery rate for system operation was determined to be 32% for a feedwater salinity of 35 g/L, and 80% for a feedwater salinity of 1 g/L.

The present work proposes a new multi-stage distillation system that was designed in UDES with the objective of increasing its productivity and improving its efficiency. The aim was to develop a simple and economic multi-stage solar still to produce freshwater for domestic and socioeconomic sector uses from seawater and brackish waters that are abundant in many remote areas of the Algerian Sahara. We study the effect of cooling water temperature and collected experimental data in order to optimize their influence on the yield of the multi-stage distillation process for the first four-tray device. The preliminary results showed a significant improvement of the overall productivity. The effect of the boiler temperature T_b is presented for different values. Indeed, the total productivity of the still is affected by the increase of the cooling water flow rate on top of the tray. The experimental results show that the first tray of the system produces about 35 l of freshwater per day and the temperature of the evaporator efficiency is fixed at 96°C. The results that permit the determination of the output of each tray of the still are presented in this study. The analysis of the distilled water showed that its quality was within the international standards (World Health Organization guidelines).

With the aim of mitigating the problem of salinity of purified waste water of the STEP (waste water treatment plant) of Ouargla, one proposed to study the possibility of integration of solar energy to solve the problem of this water intended for the irrigation of the agricultural surfaces and in particular the palm trees, which underwent major damage because of the salinity of this water. A physicochemical and biological study was carried out on a sample of 20 L, whose pH is of 8.03, a salinity of 5.2 g/l, and a conductivity of 9170 μ S/cm, we note that distillation was spread out over 5 days. The results thus carried out, do not present any danger to the animal species or vegetable, since, this water is close to the recommended standards.