In Post The role of chemicals in the purification of drinking water Daily, a massive amount of water is consumed in cities and human fortunes and refined to enter the consumption cycle. Drinking water from large cities is usually from sources stored behind dams or recycled water that contain various pathogenic microorganisms and various contaminants, so they should be well-purified and completely clear and free of any kind of human nutrient Be For this purpose, different stages of purification, such as flocculation, clarification, removal of iron and manganese, filtration, pH adjustment, disinfection, and flavor control on the water, require almost all of these processes for the use of chemicals. The purpose of water purification is to eliminate contaminants and improve the quality of water, such as the curettage, odor and color of it.
Unpurified water is friable and is bad because of the presence of colloidal particles such as soil and mud, organic matter and minerals, organic solvents and plankton and other microorganisms in water. This turbidity is measured in urban wastewater treatment plants by means of a turbidizer that measures the amount of light dispersion and absorption from the solution. These irritants, which are the most important cause of pollution and non-drinking water, can be separated by up to 99% by chemical means, so the important role of chemicals in drinking water treatment is very important.
Isolation of colloidal materials in water is carried out using some chemicals such as lime , aluminum sulfate, chlorofric and poly aluminum chloride. These compounds are the most important materials used in the treatment of drinking water and domestic and industrial sewage. Their molecular structure and their specific electrical energy can absorb bacteria, oxides, algae, carbonates, paint and clay, and, by coagulation and deposition, help reduce water turbidity. This property is called coagulation and these chemicals are coagulants.
Important role of aluminum sulfate and lime
Basically, aluminum salts such as aluminum sulfate and poly (aluminum chloride) are the most commonly used coagulants because they have the highest absorption capacity of contaminated water, especially colloid contamination. Aluminum sulfate, sometimes known as white alum, is a combination of aluminum ion and ion sulfate and can accumulate in the water suspended solids in a jelly flask and settle in reservoirs. Then the material is easily collected from the floor of the tanks. Due to the fact that most unwanted mineral substances in the water are alkaline, aluminum sulfate can control the acidity of the environment by collecting these contaminants.
Another important coagulant used in the treatment of water and sewage is lime. Lime has the properties of pH, water and microbial regulator and is one of the cheapest and most used chemicals in this sector, which is produced entirely in the country. For water purification, a special type of lime called hydrated lime with high calcium hydroxide formulation should be used. Hydrated lime has a completely powdery state and has many advantages in removing cures, removing bacteria and fungi, removing odors, and purifying water and sewage. To make more impact, lime should be used as stone powder . Limestone powder can have a faster and more effective effect as it produces the highest level of contact. Household and industrial sewage is usually acidic and, given the alkali nature of the lime, this substance is also effective for water phytate correction.
One of the stages of drinking water purification is the separation of harmful ions from human health. Because of the use of chemicals in the industry and chemical fertilizers in agriculture, wastewater and groundwater, which are part of the supply of drinking water, are contaminated with nitrate, calcium and magnesium ions. Perhaps these materials are not harmful to human health at first glance, but it should be noted that their large amounts can be detrimental to the health of the tooth, kidney and cardiovascular system, or even a threat to cancer. The presence of large amounts of these ions in water causes hardening of the water, so it is necessary to use water purification methods to purify the water.
One of the materials used to harden the water and sewage is iron sulfate. Iron sulfate has two active iron ions that has the proper ability to remove unwanted ions in the water, which is why most of the factories used to treat their waste water from sulfate Iron is used to water hardening. Iron sulfate in Persian is called green alum, and harmless, relatively inexpensive and high-quality material, and most importantly, it is easily and widely produced in the country and is available to the water treatment industry.
The role of chlorine in water purification
Chlorine or chlorine is a gaseous odor that plays an important role in disinfection of drinking water. It is a gas or its solid compounds, such as sodium hypochlorite and chlorine dioxide, with high microbial and disinfecting properties that can remove pathogens in short time. Chlorine has various functions in drinking water purification, including preventing the growth of biological mass and algae in tubes and reservoirs, eliminating the odor and odor of water and eliminating bacteria and fungi. The consumption of chlorine in water purification is very common in all countries of the world due to its low cost and high shelf life. Of course, chlorine also has harmful effects on human health, which can be ignored due to its insignificant amount in water and the significant impact it has on drinking water.