Polski
The fact that without water there is no life is known to all of us, but already the fact that fresh water resources, suitable for consumption immediately after extraction, are scarce is not widely known. The water treatment process is necessary to meet the ever-increasing demand. The constant availability of water on tap seems an obvious fact that requires no further thought. Meanwhile, we may start experiencing shortages at a basic level in the near future.
Water treatment process – what, where and how
Water treatment is the process of bringing contaminated water to a state of purity specified by standards contained in the Decree of the Minister of Health dated December 7, 2017. On the quality of water intended for human consumption.
We start the water treatment process by finding out which natural resource we have to work with. So, laboratory analyses of the water should be carried out, both in terms of physical parameters, such as, among others. turbidity, pH or color; chemical indicators, such as metals or organic compounds; and microbiological indicators, equally important for human health. Once you know the results of the study, you can “diagnose” the condition of surface water (river, lake) or groundwater (from a well), using the relevant standards.
Water whose indicators are exceeded must be treated according to the guidelines of the Ordinance, but only to the extent of the abnormal parameters. The others – which are within standards, such as the vitally important ions of magnesium, calcium, potassium or sodium for health – are left as they are. They are essential for the proper functioning of the human body, among other things. enzymes. The water treatment process must not reduce the natural qualities of the water.
Water treatment process on the example of the Dunajec River
The Dunajec, whose treatment I deal with on a daily basis, is undoubtedly a capricious mountain river, whose quality depends largely on the geological structure and atmospheric and hydrological conditions. Its physical and chemical composition is shaped mainly by atmospheric conditions that vary over time and surface runoff of mountain streams and rivers. In accordance with the Decree of the Minister of Maritime Affairs and Inland Navigation dated August 29, 2019. The waters of the Dunajec River qualify for high-performance physical and chemical treatment.
Therefore, the technological processes used at the Water Treatment Plants, which belong to Sądeckie Wodociągi Sp. z o.o., are: pretreatment in vertical settling tanks and sand filters, oxidation processes through ozonation, filtration in activated carbon bed filters and disinfection with UV light and chlorine gas. The process of water treatment is complex and multi-step.
Does the water treatment process require the use of so-called “water treatment”. chemistry?
The surface water treatment process is mostly based on complex coagulation, taking place – in our case – in pre-settlers and sand filters. Coagulation – from Latin. coagulare means to combine and refers to the process of forming clusters of solid particles (colloids) suspended in water, which under the influence of their own weight are unable to sink or sink very slowly, so it is necessary to help in the form of a chemical agent dosed into the water – coagulant, causing the particles to clump together and sink quickly to the bottom in the process of sedimentation. Here the coagulant plays the role of a “super hero” that can capture and remove unwanted turbidity, suspended solids and organic compounds from the water with cosmic speed, and metals, bacteria and viruses in the process.
As befits drinking water treatment processes, coagulation must also remain under strict control. In order to cope with this task, it was necessary to find the most effective coagulant adapted to the strict water quality parameters of the Dunajec River. Numerous laboratory and technical scale tests have indicated that an aqueous solution of aluminum hydrochloride with PZH approval is the most effective. Dosage control is done automatically, through a previously developed system and control algorithm that has been successfully implemented in the technological system.
The dose of coagulant is strictly adjusted to the current turbidity and the amount of water being treated at any given time. For this purpose, devices measuring the turbidity of the Dunajec River water and its flow were used continuously. This allows the calculation of the minimum dose, but also the most effective dose, necessary to obtain the best possible results from tests of treated water quality indicators. Thus, the saying that “more is not always better” is confirmed, as I find out every day when observing the water treatment process.
Water a common good now and in the future
Water is a unique asset inherited from generation to generation. Freshwater resources that are clean and safe for human health are declining and deteriorating year by year due to particulate, sewage and toxic pollutants.
Let’s take measures to protect freshwater resources and improve their quality right from our own backyard. Let’s read, ask and act, and above all, let’s respect the water, because we may one day run out of it….
