جستجوی مقالات مرتبط با کلیدواژه « desalination » در نشریات گروه « مهندسی شیمی، نفت و پلیمر »

In this article, the combination of a flat plate solar collector with a solar still is used for water desalination. The purpose of this study is to increase the output of the solar still by improving its performance by using a whole flat plate and investigating the effect of solar water on the amount of distilled water produced. Various effects, environment, water depth, environment, speed, and solar radiation have been studied to increase productivity. The results showed that coupling solar still with a solar collector increases the efficiency by 48%. Also, the amount of water depth in the distillation device affects the production of distilled water, and it is clear that by decreasing the depth from 3 cm to 2 cm, the amount of freshwater produced increases by 8.5%. The results obtained from the tests showed that the volume of distilled water output from the device, for an average depth of 2 cm to 4 cm, is 4.6 to 9.5 L/day using the collector and 2.4 to 1.3 L/day. It is without using it. The average radiation intensity and wind speed during the test with the collector were 1035 W/m2 and 3.7 m/s, respectively, and in the test without the collector, it was 980 W/m2 and 4.2 m/s.

Desalination process of seawater by reverse osmosis method, has attracted more attention in recent years, due to its high efficiency, and about 62 percent of seawater is treated by this method. In this process energy recovery devices play an important role in reducing energy consumption and process costs, because on the one hand the energy consumption of high pressure pumps for feeding reverse osmosis membrane is high, and on the other hand 40 percent of feed water is treated with membrane and 60 percent is discharged as a high-pressure waste, which releases a lot of energy. The energy recovery device converts this hydraulic energy of the effluent into mechanical energy and transfers it to the feed pump as a shaft aid or uses it independently to transfer a part of the feed. The purpose of this research is to study energy recovery devices and compare them with each other to select a suitable energy recovery system.

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 Today, with the development of different indus tries and the disposal of untreated was tewaters, environmental pollution and pollution of water resources are increasing very rapidly. Membrane technology is an advanced and hopeful way to treat water and was tewater. Nanofiltration technology is widely used in water treatment and desalination of seawater.

The performance of thin film polyamide membranes containing unmodified and modified manganese dioxide nanotubes was inves tigated. After hydrothermal synthesis of manganese dioxide nanotubes, the inner surface of the nanotubes was modified with polydopamine, and then, their performance in thin film polyamide membranes (in terms of monovalent/divalent ions rejection and permeation flux) was inves tigated.

Unmodified and modified nanotubes were characterized by Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and X-ray diffraction analysis (XRD). In addition, the morphology and s tructure of the thin film membranes were inves tigated by FESEM tes t and the performance of the membranes was s tudied in terms of permeation flux, contact angle and rejection of sodium and copper ions. The maximum pure water flux, 18.6 L/m2h, was obtained for the membrane containing 0.10 %wt modified nanotube; an increase of 21.88% compared to the neat membrane. Creation of tiny pores on the surface of the membranes through hydrophilic nanotubes resulted in higher flux while there are extra routes through the nanotubes for water permeation. The maximum rejection of sodium ion (97.02%) for the membrane containing 0.2 %wt modified nanotubes could be related to the s tacking of the nanotubes and more spatial hindrance, reduction in the diameter of the nanotube due to the coating and permeation of water through the nanotubes.

Oil-associated salts, depending on their origin, usually contain sodium, potassium, and magnesium. One of the best and most effective ways to separate salt water from crude oil is to use an electrostatic field. In this method, the droplets are polarized in the presence of an electric field and an electrostatic force is created between them, which causes the droplets to approach and coagulate. Using an electric field, the coagulation rate of a dispersed phase in an emulsion can be increased. Therefore, methods based on electric current have been proposed. From an energy efficiency point of view, electrical separation is the best way to break the emulsion and desalinate the oil. Therefore, an electric current is used when the salt water droplets are difficult to separate from the oil. The basic principles of electrostatic desalination of crude oil can be summed up as the application of small droplets of water under an electric field and the formation of larger droplets of water with higher settling velocities.

This study aims to propose a method for the thermal recovery of regenerated bed in a two-bed adsorption desalination system. It investigates the affection of thermal recovery, heating water temperature, and cooling water temperature entering the bed and condenser on the performance of the system. The analysis demonstrated that at a constant temperature of cooling water, the amount of water that is produced increases by raising the temperature of hot water and the energy consumption does not change significantly. For example, at a cooling water temperature of 20 °C, by increasing the temperature of heating water from 50 to 90 °C, the water that is produced is 3.75 times more and the energy consumption is reduced by 7.4 %. Heat recovery reduces the energy consumption of the system. As the temperature of the hot water increases, the effect of thermal recovery increases. As a result of heat recovery at a heating water temperature of 50 and 90 °C, the energy consumption of the system decreases by 10.9 % and 37.6 %, respectively. Increasing the temperature of the inlet cooling water to the bed and the condenser reduces the production of water and increases the energy consumptionof the system. The effect of the temperature of cooling water entering the condenser on the water that is produced and the energy consumption is greater than that of the cooling water entering the bed. As the cooling water temperature increases, the energy-saving as a result of thermal recovery decreases. For example, At a cooling water temperature of 10 °C, thermal recovery reduces the energy consumption of the system by about 47 %, while at 23°C it is about 12 %. Again the effect of cooling water temperature that enters the condenser is more than that enters the bed. By increasing the temperature of cooling water entering the condenser from 15 to35°C, energy savings due to the heat recovery reduces from 53.7 to 9.3 %.

Due to the increase in population and as a result of the increase in economic activities in the world, the demand for water consumption has increased significantly. Seawater covers two-thirds of the earth's surface, so it makes sense to use these resources to provide drinking water and could be an important component in solving the problem of water scarcity. In addition, existing technologies for water treatment to meet There are certain water quality requirements, so reusing used water to address water shortages can be further explored. In recent years, organic metal frameworks have received much attention due to their interesting chemistry and potential applications. In the science of separation, researchers have extensively studied organic-metal frameworks for gas separation and water treatment. In this paper, the aim is to investigate the possibility of using organic-metal frameworks for membrane desalination. Therefore, after a brief introduction of organic-metallic frameworks, several methods for preparing membranes of organic-metallic frameworks, water desalination techniques and methods of application of organic-metallic frameworks and finally membranes of organic-metallic frameworks for different applications of water Such as desalination, nanofiltration, ultrafiltration and microfiltration are considered. The use of organic-metal frameworks as membranes in water treatment is still in its infancy compared to other applications such as gas separation.