Urban Water Treatment Systems
We design urban treatment systems with aeration (if necessary), chemical treatment (coagulation/ flocculation/ precipitation), filtration, and disinfection (with chlorine) processes. After conventional treatment, advanced treatments such as oxidation (ozone or chemical), adsorption (activated carbon), ion exchange, and membrane systems (ultrafiltration, nanofiltration, reverse osmosis) can be added to the process.
In recent years, underground water reserves, where most of the water needs are met, are increasingly unable to meet the need. It is mandatory to use surface water (streams and lakes) resources in the supply of drinking and potable water. However, for many years, water quality has deteriorated in many river basins as a result of the use of surface water resources as receiving media that accepts waste (TUSIAD, 2008). For this reason, when surface water is used for drinking and potable water needs, it is almost always necessary to undergo treatment processes. As of today, in many settlements, especially in large cities, surface water is offered for consumption to drink and use water. Before the distribution, the quality of water is necessarily improved through drinking water treatment plants and brought to the desired quality. On the other hand, as a result of the deterioration of the quality of groundwater, there is a need to treat also groundwater like surface water.
Coagulation, Flocculation, Sedimentation (simple or lamellar precipitation)
Sand filtration systems (pressure, gravity, slow)
Arsenic Removal Filtration
Water Softening System
Activated Carbon Filters
Disinfection systems (UV systems, ozone, and chlorine disinfection systems, activated carbon adsorption)
Conventional water treatment methods have been used to remove chemical and microbiological impurities that pose a risk to human and environmental health.
In conventional treatment systems, aeration (if the oxygen content is low), sedimentation (if the water is taken directly from surface water sources), chemical treatment (coagulation/tangling/ precipitation), filtration, disinfection (usually chlorination) operations are applied.
Additionally, softening operations are performed where the hardness is very high; iron and manganese removal operations are performed when the iron and manganese content is high. It includes ventilation, coagulation, tangling, precipitation, sand filtration, and disinfection units. Ozone for primary (pre) disinfection purposes, activated carbon adsorption for advanced purification, and reverse osmosis are some recent advances.
Conventional treatment plants are usually required when surface water sources are used. In areas where spring or clean well water is used, water is provided to the network just after chlorination.
One of the oldest and most widely used methods in drinking water treatment is filtration. The filtration process is one of the sine-qua-non units of conventional drinking water treatment, the purification mechanism is to keep impurities in the water in the gaps between the filter material.
Filtration, sedimentation, adsorption, tangling, and biological processes are effective during filtration. As a result of these mechanisms, solids, turbidity, organic compounds, inorganic substances such as clay, silt, iron and manganese, and pathogenic microorganisms suspended in water are removed.
Filters can usually be grouped into slow sand filters (SSF), fast sand filters (FSF), pressure filters (PF) depending on the speed of passage of water (superficial hydraulic load or filtration speed). Applications such as submerged filters, dry filters or downstream-upstream filters are also possible. In urban drinking water treatment plants, SSF (for low flow rates/populations) or FSF is more commonly used. Pressure filters, on the other hand, are generally preferred in water preparation units of industrial plants due to their advantage of saving space.
Chemical treatment processes are all the methods that require the addition of chemicals. Neutralization (pH adjustment), coagulation/flocculation, chemical oxidation/reduction, and disinfection can be considered in this context.
Disinfection is the process of destroying microorganisms that can be harmful to human health in water. In the case of the use of ozone for pre-disinfection purposes, chlorine dosing (final disinfection) is performed to prevent water contamination in the network system. Among the methods that can be applied for disinfection 1) physical methods (heat, UV, sunlight, electromagnetic, sound), 2) chemical methods (Chlorine and its compounds, halogens, ozone, permanganate, phenolic compounds, hydrogen peroxide, alkali, and acids, etc.), 3) mechanical methods (elimination, precipitation, etc.) are included.