Brine is a high-concentration solution of salt in water. In different contexts, brine may refer to salt solutions ranging from about 3.5% up to about 26%. Lower levels of concentration are called by different names: fresh water, brackish water, and saline water.
Ultrafiltration (UF) is a variety of membrane filtration in which forces like pressure or concentration gradients lead to a separation through a semipermeable membrane. Suspended solids and solutes of high molecular weight are retained in the so-called retentate, while water and low molecular weight solutes pass through the membrane in the permeate (filtrate). This separation process is used in industry and research for purifying and concentrating macromolecular (103 - 106 Da) solutions, especially protein solutions.
Forward osmosis (FO) is an osmotic process that, like reverse osmosis (RO), uses a semi-permeable membrane to effect separation of water from dissolved solutes. The driving force for this separation is an osmotic pressure gradient, such that a "draw" solution of high concentration, is used to induce a net flow of water through the membrane into the draw solution, thus effectively separating the feed water from its solutes. In contrast, the reverse osmosis process uses hydraulic pressure as the driving force for separation, which serves to counteract the osmotic pressure gradient that would otherwise favor water flux from the permeate to the feed. Hence significantly more energy is required for reverse osmosis compared to forward osmosis.
Multi-stage flash distillation (MSF) is a water desalination process that distills sea water by flashing a portion of the water into steam in multiple stages of what are essentially countercurrent heat exchangers. Multi-stage flash distillation plants produce about 26% of all desalinated water in the world, but today virtually all new desalination plants use reverse osmosis due to much lower energy consumption.
Solar desalination is a technique to desalinate water using solar energy. There are two basic methods of achieving desalination using this technique; direct and indirect. Sunlight may provide heat for evaporative desalination processes, or for some indirect methods, convert to electricity to power a membrane process.
A reverse osmosis plant is a manufacturing plant where the process of reverse osmosis takes place. An average modern reverse osmosis plant needs six kilowatt-hours of electricity to desalinate one cubic metre of water. The process also results in an amount of salty briny waste. The challenge for these plants is to find ways to reduce energy consumption, use sustainable energy sources, improve the process of desalination and to innovate in the area of waste management to deal with the waste. Self-contained water treatment plants using reverse osmosis, called reverse osmosis water purification units, are normally used in a military context.
Nanofiltration (NF) is a relatively recent membrane filtration process used most often with low total dissolved solids water such as surface water and fresh groundwater, with the purpose of softening and removal of disinfection by-product precursors such as natural organic matter and synthetic organic matter.
A solar-powered desalination unit produces potable water from saline water through direct or indirect methods of desalination powered by sunlight. Countries such as Australia, Italy and Egypt have adopted this system as an alternative source of water for the population. Solar energy is the most promising renewable energy source due to its ability to drive the more popular thermal desalination systems directly through solar collectors and to drive physical and chemical desalination systems indirectly through photovoltaic cells.
Sergey Vladimirovich Polyakov is a Russian-American scientist performing research for USPolyResearch. He is best known for his R&D in space technology and chemical engineering including the theoretical and experimental studies of the performance of life support systems (LSS) for Soviet interplanetary spaceships and the MIR and ALPHA orbital stations using a ground-based Martian expedition real-scaled simulator on YouTube in the Institute for Biomedical Problems. Developed an integrated approach to the design of air revitalization and water reclamation/conditioning system from human wastes on the basis of energy-efficient membrane and depth-filtration methods.
A pressure exchanger transfers pressure energy from a high pressure fluid stream to a low pressure fluid stream. Many industrial processes operate at elevated pressures and have high pressure waste streams. One way of providing a high pressure fluid to such a process is to transfer the waste pressure to a low pressure stream using a pressure exchanger.
Membrane fouling is a process whereby a solution or a particle is deposited on a membrane surface or in membrane pores in a processes such as in a membrane bioreactor, reverse osmosis, forward osmosis, membrane distillation, ultrafiltration, microfiltration, or nanofiltration so that the membrane's performance is degraded. It is a major obstacle to the widespread use of this technology. Membrane fouling can cause severe flux decline and affect the quality of the water produced. Severe fouling may require intense chemical cleaning or membrane replacement. This increases the operating costs of a treatment plant. There are various types of foulants: colloidal, biological, organic and scaling.
Richard Lindsay Stover, Ph.D., pioneered the development of the PX Pressure Exchanger energy recovery device Energy recovery that is currently in use in most seawater reverse osmosis desalination plants in existence today.
Reverse osmosis (RO) is a water purification process that uses a partially permeable membrane to remove ions, unwanted molecules and larger particles from drinking water. In reverse osmosis, an applied pressure is used to overcome osmotic pressure, a colligative property, that is driven by chemical potential differences of the solvent, a thermodynamic parameter. Reverse osmosis can remove many types of dissolved and suspended chemical species as well as biological ones (principally bacteria) from water, and is used in both industrial processes and the production of potable water. The result is that the solute is retained on the pressurized side of the membrane and the pure solvent is allowed to pass to the other side. To be "selective", this membrane should not allow large molecules or ions through the pores (holes), but should allow smaller components of the solution (such as solvent molecules, i.e., water, H2O) to pass freely.
Australia is the driest habitable continent on Earth and its installed desalination capacity comprises around 1% of the world’s total. Until a few decades ago, Australia met its demands for water by drawing freshwater from dams and water catchments. As a result of the water supply crisis during the severe 1997–2009 drought, state governments began building desalination plants that purify seawater using reverse osmosis technology.
The Minjur Desalination Plant is a reverse osmosis, water desalination plant at Kattupalli village, a northern suburb of Chennai, India, on the coast of the Bay of Bengal that supplies water to the city of Chennai. Built on a 60-acre site, it is the largest desalination plant in India. Construction works were carried out by the Indian company IVRCL and the Spanish company Abengoa, under the direction of the Project Manager Fernando Portillo Vallés and the Construction Manager Juan Ignacio Jiménez-Velasco, who returned to Europe after the inauguration of the plant to work on Renewable Energy Projects. Originally scheduled to be operational by January 2009, the work on the plant was delayed due to Cyclone Nisha in October 2008, which damaged a portion of the completed marine works and destroyed the cofferdam meant for the installation of transition pipes. The trial runs were completed in June 2010 and the plant was opened in July 2010. Water from the plant will be utilised chiefly for industrial purposes such as the Ennore Port and North Chennai Thermal Power Station. However, during droughts, water from the plant will be supplied to the public, serving an estimated population of 1,000,000.
Modern Water plc is a British company which was first listed on the AIM submarket of the London Stock Exchange on the 12 June 2007. It owns, installs and operates advanced membrane technologies and develops and supplies systems for water monitoring.
Water issues in developing countries include scarcity of drinking-water, poor infrastructure for water access, floods and droughts, and the contamination of rivers and large dams. Over one billion people in developing countries have inadequate access to clean water. Millions of women spend hours everyday collecting water, 2.6 billion people lack access to sanitation, and 1.8 million children die each year from diarrhea. Barriers to addressing water problems in developing nations include poverty, education, climate change, and poor governance.
The Nemmeli Desalination Plant is a water desalination plant at Nemmeli, Chennai, on the coast of the Bay of Bengal that supplies water to the city of Chennai. It is located about 35 km south of the city centre, along the East Coast Road. Built at a cost of ₹ 5,333.8 million, the plant is the second desalination plant in the city after the 100-MLD plant at Minjur and itself has a capacity to treat 100 million litres of seawater a day.
