Furthermore, it can be very effective in removing fine particles that are otherwise very difficult to remove. One of the advantages of coagulation ais that it reduces the time required to settle out suspended solids. Here aggregation of the flocs takes, which settle out to form sludge that will need to be removed. The next stage is the sedimentation tank. Raw water quality near to the inlet of a mixing tank or flocculator determines the rate in which coagulants are dosed in solution.īy adding coagulant at a point of high turbulence, it is rapidly and thoroughly dispersed on dosing. After sedimentation and/or filtration, the floc is separated from the treated waterĪluminium sulphate and ferric sulphate are two of the most commonly used coagulants, although others are available. How does the water treatment process work?Ĭoagulation, flocculation and sedimentation are processes used to remove colour, turbidity, algae and other microorganisms from surface waters.Ĭhemical coagulants can be added to the water for the formation of a precipitate, or floc to entrap these impurities. As a result, specialised water treatment methods may also be part of water treatment to help control formation and removal.įurthermore, under renewed regulations, tighter limits could be placed on endocrine disrupting chemicals as well as lead limits being halved. Some water supplies may contain disinfection by-products, inorganic chemicals, organic chemicals and radionuclides. As a result, multiple treatment steps are required and individual processes are required that will enable the configuration of different comabinations to clean and finally disinfect the abstracted water. This raw water is subject to direct environmental input. Surface water treatment works take water from above ground sources, such as rivers, lakes and reservoirs. These sources tend to be relatively clean in comparison to surface water, with fewer water treatment steps required. For example, groundwater treatment works abstract water from below ground sources such as aquifers and springs. For example, filtration can prepare water to ensure it is suitable of UV (ultraviolet) disinfection.ĭepending on the quality and type of the water entering a water plant, treatment may vary. The latter allows effective water treatment and allows each stage to treat and prepare water to a suitable quality for the next downstream process. This can include the initial pre-treatment by settling or through using coarse media, filtration followed by chlorination, called the multiple barrier principle. Water treatment consists of several stages. If a persistent disinfectant, such as chlorine, is added this can also act as a residual to help prevent biological regrowth during water storage or distribution in larger systems. Following this, a final disinfection stage is nearly always included at the end of the treatment process to help deactivate any remaining microorganisms. Many treatment systems are designed to remove microbiological contamination and physical constituents, including suspended solids (turbidity). To ensure they do not present a health risk, nearly all water sources require treatment before they can be consumed. Replicating the earth’s hydrological cycle in which water is continuously recycled, treatment enables the same water to be cleansed through several natural processes. Thanks to significant technological developments in water treatment, including monitoring and assessment, high-quality drinking water can be supplied and enjoyed around the world. Maintaining water treatment to ensure a clean supply to meet growing global populations has been an ongoing challenge throughout human history.
Water treatment: mimicking earth’s hydrological cycle What is water treatment? The following article provides an overview of the basic principles of water treatment and the processes and technologies involved. Depending on the continent, country and region, different water treatment systems may be in operation depending on regional regulations and raw water input. Public drinking water systems use a variety of methods to provide safe drinking water for their communities. Water sources can be subject to contamination and therefore require appropriate treatment to remove disease-causing agents. Water treatment and water treatment technologies are an essential line of defence to remove contaminants and bacteria before the delivery of clean, potable water supplies for consumption.
Types of water treatment chemicals (and why they are used).Ozone water treatment: harnessing the power of lightning.UV water treatment: shining a light on disinfection.Six essential Water treatment technologies.How does the water treatment process work?.