Membrane Systems for Seawater and Brackish Water Desalination

Fouling of high pressure-driven NF and RO membranes in desalination processes: Mechanisms and implications on salt rejection

Both brackish water desalination and seawater desalination processes are well established and in common use around the globe to create new water supply sources. The farther the location of the source water from the ocean or seashore, the lower the salinity (TDS) of the water and the lower the osmotic pressure that needs to be overcome when desalinated water is produced. This is one of the major reasons that brackish desalination is often considered less costly than seawater desalination. A number of project considerations, however, indicate that seawater desalination can be beneficial and more cost-effective than brackish water desalination. To make a fair comparison, we need to properly compare all major aspects of both types of projects to define the best and most appropriate desalination technology. While brackish water has less feed water TDS, it is more challenging to dispose of the produced concentrate. Also, although brackish water desalination needs less energy to overcome osmotic pressure, it usually requires more energy to draw the water from the well than it takes to pump seawater from the open ocean intake. Another factor is that the temperature of the brackish well water may be lower than the temperature of ocean water, giving seawater desalination an advantage in energy demand. In comparing brackish to seawater desalination, these major aspects should be evaluated: (1) Locations of seawater and brackish water plants, relative to the major consumers of the desalinated water, (2) Transportation (pumping and disposal) costs of the feed water and produced water, (3) Potential colocation of a seawater plant with a large industrial user (e.g., power plant) of the seawater for cooling or other purposes, (4) Produced quality of brackish water and seawater desalination in terms of major minerals and emerging contaminants, (5) Sustainability of the water source: capacity and depth of the brackish water wells, as well as the type of soil. (6) Technical and economic aspects of produced concentrate disposal, (7) Permitting process costs for brackish and seawater desalination, and (8) The economics of both brackish and seawater desalination treatment processes: capital costs, operational and maintenance (O&M) costs, lifetime water cost, and total water cost (TWC). This paper discusses the major evaluation criteria and considerations involved in properly comparing the economic and technical aspects of brackish and seawater desalination to determine the more favorable desalination technology for a given desalination project.

Reverse osmosis is the leading technology for desalination of brackish water and seawater, important for solving the growing problems of fresh water supply. Thermal technologies such as multi-effect distillation and multi-stage flash distillation still comprise an important portion of the world’s desalination capacity. They consume substantial amounts of energy, generally obtained from fossil fuels, due to their low efficiency. Hybridization is a strategy that seeks to reduce the weaknesses and enhance the advantages of each element that makes it up. This paper introduces a review of the most recent publications on hybridizations between reverse osmosis and thermal desalination technologies, as well as their integration with renewable energies as a requirement to decarbonize desalination processes. Different configurations provide improvements in key elements of the system to reduce energy consumption, brine production, and contamination, while improving product quality and production rate. A combination of renewable sources and use of energy and water storage systems allow for improving the reliability of hybrid systems.

Chapter 4 - Solar-driven water treatment: generation II technologies

The role of desalination in bridging the water gap in Jordan

Seawater desalination is one of the most widely used technologies for freshwater production; however, its high energy consumption remains a pressing global challenge. Both the development and utilization of sustainable energy sources are anticipated to mitigate the energy shortages associated with seawater desalination while also effectively addressing the environmental issues linked to fossil fuel usage. This study provides a comprehensive overview of the classification and evolution of traditional desalination technologies, emphasizing the advancements, progress, and challenges associated with integrating various sustainable energy sources into the desalination process. Then, the cost, efficiency, and energy consumption of desalination systems driven by sustainable energy are discussed, and it is found that even the most widely used reverse osmosis (RO) technology driven by fossil fuels has CO2 emissions of 0.3–1.7 kgCO2/m3 and the lowest cost of desalinated water as high as 0.01 USD/m3, suggesting the necessity and urgency of applying sustainable energy. A comparison of different seawater desalination systems driven by different sustainable energy sources is also carried out. The results reveal that although the seawater desalination system driven by sustainable energy has a lower efficiency and a higher cost than the traditional system, it has more potential from the perspective of environmental protection and sustainable development. Furthermore, the efficiency and cost of desalination technology driven by a single sustainable energy source is lower than that driven by multi-sustainable energy sources, while the efficiency of desalination systems driven by multi-sustainable energy is lower than that driven by hybrid energy, and its cost is higher than that of desalination systems driven by hybrid energy. Considering factors such as cost, efficiency, consumption, economic scale, and environmental impact, the integration of various seawater desalination technologies and various energy sources is still the most effective strategy to solve water shortage, the energy crisis, and environmental pollution at present and in the future.

Sea water desalination becomes more and more important as the consumption of fresh water. Forward osmosis (FO) is a novel technology for sea water or brackish water desalination, where a most important device, semi-permeable membrane, are required low resistance, high selection and inexpensive. In this study, based on molecular dynamic simulations, we explored the performance of porous graphene as the semi-permeable membrane for sea water desalination. Fluorine (F) and nitrogen (N) are adopted to optimize the property of graphene pore. We found that although pure pore have highest water flux (indicating lower resistance), N modified pore has the best selection due to the high electronegativity of N atoms. The about 60 L/cm2/h water flux and 100% solute rejection ratio confirm the graphene with N modified pores is good candidate as a semi-permeable membrane for sea water desalination.

Fresh water deficit has been an increasingly critical global environmental issue, and seawater desalination is considered as the most effective and promising solution, which promotes the development of different desalination technologies. In order to provide a comprehensive knowledge about the development of desalination technologies, state-of-the-art of research and development on the application of desalination technologies is reviewed in this paper. At first, the overview of desalination technologies is briefly introduced, including the definition of desalination, the evaluation index of water quality and the resulting classification of water resources, the overview of desalination industry, the usages of freshwater produced by desalination, and the sources of raw water. Besides, conventional desalination methods are categorized into physical method and chemical method according to whether there is new substance generated in the desalination process. In the following section conventional desalination methods are reviewed from the perspectives of basic processes and principles, the performances and technical characteristics. However, the shortcomings of conventional desalination technologies mainly lie in high energy consumption and complex treatment process, such as the decrease of heat transfer coefficient caused by the scaling and fouling generated on the solid heat transfer walls for multi-stage flash (MSF) and multiple effect distillation (MED), and rigorous pre-treatment and low recovery factor for reverse osmosis (RO). With the aims of overcoming these disadvantages and thus decreasing the energy consumption, different improvements have been put forward and new desalination methods have been developed. Therefore, the development of desalination technology is then exhaustively analyzed and forecasted in the following four aspects: improvement for the existing technology, combination of different technologies, desalination technology in combination with new energy, and development of new desalination technologies utilizing unemployed physical phenomena. The improvements mainly focus on the shortcomings of MSF, MED and RO, which are the current major large-scale industrial desalination technologies. The combination of different technologies can integrate their respective advantages to improve the desalination performance and decrease the energy consumption and the cost. The limitations of the decrease of traditional fossil energy and its increasing cost can be broken through the combination with solar, wind, geothermal, ocean and nuclear energies, which is also regarded as a potential solution for climate change. The newly developed desalination technologies have the advantages of lower energy consumption and cost, but most of which are still in lab-scale and need further improvement. Due to the important role in the assessment of the desalination efficient, special attention is paid to the analysis of energy consumption of each desalination technology.

Seawater desalination — SWCC experience and vision

Side effects of antiscalants on biofouling of reverse osmosis membranes in brackish water desalination

Hybrid membrane system for desalination and wastewater treatment : Integrating forward osmosis and low pressure reverse osmosis

This article deals with the desalination of seawater and brackish water, which can deal with the problem of water scarcity that threatens certain countries in the world; it is now possible to meet the demand for drinking water. Currently, among the various desalination processes, the reverse osmosis technique is the most used. Electrical energy consumption is the most attractive factor in the cost of operating seawater by reverse osmosis in desalination plants. Desalination of water by solar energy can be considered as a very important drinking water alternative. For determining the electrical energy consumption of a single reverse osmosis module, we used the System Advisor Model (SAM) to determine the technical characteristics and costs of a parabolic cylindrical installation and Reverse Osmosis System Analysis (ROSA) to obtain the electrical power of a single reverse osmosis module. The electrical power of a single module is 4101 KW; this is consistent with the manufacturer's data that this power must be between 3900 kW and 4300 KW. Thus, the energy consumption of the system is 4.92 KWh/m3.Thermal power produced by the solar cylindro-parabolic field during the month of May has the maximum that is 208MWth, and the minimum value during the month of April, which equals 6 MWth. Electrical power produced by the plant varied between 47MWe, and 23.8MWe. The maximum energy was generated during the month of July (1900 MWh) with the maximum energy stored (118 MWh).

Design recommendations for solar organic Rankine cycle (ORC)–powered reverse osmosis (RO) desalination

Significance, evolution and recent advances in adsorption technology, materials and processes for desalination, water softening and salt removal

Design of a 1.4 mgd desalination plant based on MSF and RO processes for an arid area in India