Sharif Digital Repository

Agriculture is one the most water consuming sections in the world and roughly 60% of water demand is dedicated for this purpose. A seawater greenhouse manages to combine fan and pad greenhouse with humidification-dehumidification desalination in order to achieve water production next to agriculture products using moister in air which was used for cooling. The most important aspect of a seawater greenhouse is the amount of produced water. Many research on the condenser type and materials have been conducted in order to achieve a better performance, suggesting the utilization of a low temperature water source for the condenser. In this research, using a thermodynamic correlations to model the... 

In recent years carbon nanotubes and other carbon nanostructures such as graphene sheets have attracted a lot of attention due to their unique mechanical, thermal and electrical properties. These structures can be used in desalination of sea water, removal of hazardous substances from water tanks, gases separation, and so on. The nano porous single layer graphene membranes are very efficient for desalinating water due to their very low thickness. In this study, the mechanism of passing water and salt ions through nano porous single-layer graphene membrane are simulated using classical molecular dynamics. In the simulation, in order to separate salt ions from the water, the effects of applied... 

The subject of this thesis to assessment environmental impacts of active desalination plants in Kish Island, which explains the problems derived from concentrate discharges in to the sea, sewage network, absorbing wells and ground surface.
It also studies its impacts on land and marine ecosystem and underground aquifers that are strategic resources in Kish Island. In addition, the environmental studies done in other countries, the existing regulations and by laws in the field of environmental impacts of desalination plants and concentrate discharges are re-mentioned. Concentrates contain chemicals, which are used in pre-filtration of MED and Ro systems, which are dangerous for marine... 

The purpose of the current study is the thermodynamic, economic and environmental analysis of a cogeneration system capable of generating power, freshwater and/or air conditioning (AC) used in buildings. A photovoltaic-thermal system was used in conjunction with a concentrated reflector in order to generate power and heat. Photovoltaic cells and the cogeneration cycle turbine were tasked with generating electric power. In addition, a portion of the heat generated by the thermal collector was used to preheat the working fluid of the third-generation cogeneration cycle and another portion was used to produce freshwater. In order to provide the AC needed during summer, the cogeneration cycle... 

Energy and environmental crises force different countries to consider new clean sources of energy, especially renewable energies. Fortunately, Iran is located on the solar belt and has a great potential to utilize this huge source of clean, sustainable, accessible and cheap energy. One of the applications of the solar energy is desalination of salty and polluted waters. In this regard, the performance of Multiple Active Solar Stills is investigated in this research. To do so, four similar samples of this device with one, two, three and four stages, were constructed on which many experiments were conducted for 24 hours periods. Experiments were conducted in both continuous (several days) and... 

Membrane filtration systems are one of the most widely used and effective methods for desalination of saline water in the seas and oceans and treatment of industrial and domestic effluents in order to provide the fresh water resources needed for human survival on the earth and also meet the needs of various industries. The low efficacy of the traditional technologies necessitates the introduction of novel desalination methods. For this purpose, carbon-based membranes have been proposed as high-performance membranes because of their high mechanical strength, ultrafast permeation, and controllable pore size. In this study, by conducting molecular dynamics simulations, the effects of electric... 

Microbial desalination cells have been considered as one of the most promising technologies in water desalination and wastewater treatment. Due to slow biological processes, experimental approach toward these types of cells has always been a challenge. Consequently, modeling and simulation techniques are crucial to be developed in order to avoid wasting time and resources.In this study, a dynamic model for a microbial desalination cell consisting of three parts: anode, cathode and desalination section is proposed in which changes in microorganism concentration, acetate concentration as anode feed, oxygen concentration in cathode, pH changes and electrical potential drop in anode and cathode... 

Water desalination is one of the most important issues for human being. Water desalination is the whole process of removing salts from water. This process is widely used in urban, industrial, and commercial applications and its efficiency has been improved with the development of desalination industry. One of the new methods of water desalination is membrane distillation, in which water desalination is performed using an appropriate membrane. In this research work, the membrane distillation process of saline water has been modeled and simulated using Comsol Multisphysics software through simultaneously solving the governing equations of momentum, thermal energy and mass transfer. The model... 

The current work studies the economic investigation of reverse osmosis (RO) desalination unit and multi-effect distillation (MED) considering the average global and also Iran circumstances. Technical and operational parameters are taken into account for economic modeling of both methods to choose the proper and economic method for water desalination based on different operational conditions. The cost of the desalination plants is investigated in two different parts of capital cost and operating and maintenance cost. Capital cost is divided into direct and indirect cost subsections. Based on these calcifications, the effect of economic parameters on change of capital cost and operating and... 

Water plays an essential role in the daily lives of humans, plants, and animals. Due to the lack of safe water on the planet, in recent years there have been many challenges in the field of water treatment, which has made water desalination technology always one of the most advanced technologies. The most advanced technology in this field is the use of nanotechnology in water and wastewater treatment, especially the use of Membrane processes such as reverse osmosis. Unlike conventional reverse osmosis membranes, nanoporous membranes can ensure rapid water transfer during the displacement process. The purpose of this thesis is to introduce new monolayers that have an incredible performance in... 

More than 80% of desalination units in the Persian Gulf use multi-stage flash (MSF) technology. The discharge of effluent from these units sometimes causes severe impacts to the marine environment due to the increase in temperature and salinity around the discharge point. In the current thesis, the geometrical, mixing and turbulence characteristics of the discharge of thermal-saline inclined jets under the water surface, similar to the effluent of MSF units, are numerically investigated by developing the buoyantBoussinesqPimpleFoam solver in the OpenFoam open-source software, using the LES turbulence model and the dynamic Smagorinsky subgrid scale and the UNESCO equation of state. The...