Water is the most essential resource for human life. Without it, we could not live as we know it. Despite its importance, drinking water is a limited resource, which has led to the need to implement methods to make water suitable for human consumption. The water purification process is crucial, especially considering that climate change and droughts are causing a decrease in natural water sources. In this regard, water treatment plants play a key role.
Drinking water is defined as water that can be consumed without risk to health . Water treatment plants are infrastructures designed to collect raw water from natural sources such as rivers or reservoirs, treat it, and make it suitable for human consumption. This article explains in detail what a water treatment plant is, how it works, and why it is so important in modern society.
Characteristics of a water purifier
Water treatment plants are complex facilities that collect raw water from various sources, generally rivers, reservoirs, lakes, and aquifers. This water undergoes a series of treatments that remove impurities and harmful microorganisms, making it safe for consumption. In Spain , there are approximately 1.300 water treatment plants in operation, producing about 250 liters of drinking water per person per day.
These facilities supply water not only to homes, but also to businesses, industries, and for crop irrigation. The main objective is to guarantee a sufficient supply of quality water to meet all the daily needs of the population.
Processes of a water treatment plant
The water purification process consists of several stages, each of them with the aim of eliminating the different impurities and contaminants present in raw water. Below, we will detail each of these phases:
1. Recruitment
The first step in a water treatment plant is to capture raw water from its natural source. Water sources include rivers, lakes, reservoirs or underground wells. Once captured, the water is transported to the treatment plant, sometimes using the gravity of the ground to reduce costs. However, if the plant facilities are at a higher elevation, a pumping station will be necessary, which increases energy costs.
2. Pretreatment
Once at the plant, the water undergoes pretreatment to remove larger and more obvious elements such as leaves, branches or stones. This pretreatment includes the use of screens of different sizes that retain these residues. Additionally, the sand removal process is carried out, in which the sand and smaller particles are sedimented in special channels. At this point, reagents such as activated carbon are also added to improve the taste of the water and prevent the growth of algae.
3. Clarification
The clarification process involves adding coagulating agents, which clump together the fine particles in the water, forming flocs. These flocs are larger particles that are easily separated by gravity. This process is crucial for removing microscopic impurities of natural origin present in the water.
4. Decantation and sedimentation
Once the flocs have formed, the water is channeled into large sedimentation tanks called settling tanks. There, by the action of gravity, the flocs fall to the bottom while the clearer water remains on the surface. There are several types of settling tanks, depending on the characteristics of the target water, such as lamellar settling tanks or sludge recirculation tanks.
5. Filtration
After decantation, the water undergoes a filtration stage through beds of silica sand of varying grain sizes, where the smallest particles not retained in the previous stages are removed. This process ensures that the water is free of unwanted sediments.
6. Disinfection
In the final stage, the water is disinfected. The goal of this stage is to eliminate any microorganisms that may still be present after the previous treatments, such as bacteria, viruses, or protozoa. Chlorine is generally used as the primary disinfectant due to its high effectiveness and low cost. Ozone or UV light can also be used for more advanced treatment, depending on the water source and local regulations.
In addition to primary disinfection, the water is subjected to quality tests to verify that it meets the standards established for consumption. The treated water is then pumped into the distribution networks and reaches homes, businesses and industries.
Importance of water purification
Water purification is a crucial process not only for ensuring access to clean water, but also for preventing the spread of disease. Some of the most common diseases related to consuming contaminated water include:
- Diarrhea
- Cholera
- Hepatitis A
- Typhoid fever
- legionellosis
Access to clean water is essential to ensure public health and well-being. In areas where access to clean water is limited, the installation of water treatment plants has been crucial to improving living conditions and reducing waterborne diseases.
Another fundamental aspect of water treatment is its impact on agriculture and industry. Industrial processes alter the characteristics of water, so ensuring that reused water complies with regulations is also a key aspect of protecting ecosystems.
In a context where climate change is causing greater water scarcity, water treatment plants are essential to ensure a sustainable, balanced and safe supply of drinking water .
In short, water treatment plants are not only necessary for our daily consumption, but also to ensure the functioning of industries, agriculture and the sustainability of ecosystems. It is increasingly important to use advanced technologies in water treatment to optimize resources and minimize waste.