What is the purpose of adding chlorine to water during treatment?
surface water percolates through the soil to form groundwater What is the purpose of adding chlorine to water during the water treatment process? to kill bacteria that have accumulated, as well as prevent future bacterial growth
What is chlorination and how does it work?
Chlorination is the process of adding chlorine to drinking water to kill parasites, bacteria, and viruses. Different processes can be used to achieve safe levels of chlorine in drinking water. Using or drinking water with small amounts of chlorine does not cause harmful health effects and provides protection against waterborne disease outbreaks.
Is chloramine or chlorine better for disinfection?
The U.S. Environmental Protection Agency (EPA) allows drinking water treatment plants to use chloramine and chlorine to disinfect drinking water. Research shows that chloramine and chlorine both have benefits and drawbacks. Chlorine is a highly effective method of disinfection.
Why are some water utilities switching from chlorine to chloramine?
Sometimes there is not enough chlorine left to kill germs in the water by the time it reaches the end of the pipes. Chloramine can last longer in the water pipes and produces fewer disinfection by-products. To meet EPA standards intended to reduce disinfection by-products, some water utilities are switching to chloramine.
Why is chlorine added to water?
Chlorination is the process of adding chlorine to drinking water to kill parasites, bacteria, and viruses. Different processes can be used to achieve safe levels of chlorine in drinking water. Using or drinking water with small amounts of chlorine does not cause harmful health effects and provides protection against waterborne disease outbreaks.
What is the process of adding chloramine to drinking water to disinfect it and kill germs?
Chloramination is the process of adding chloramine to drinking water to disinfect it and kill germs. It is sometimes used as an alternative to chlorination. Chloramines are a group of chemical compounds that contain chlorine and ammonia.
What is the best disinfectant for drinking water?
Several major U.S. cities such as Philadelphia, San Francisco, Tampa Bay, and Washington, D.C. use chloramine to disinfect drinking water. Chloramine is recognized as a safe disinfectant and a good alternative to chlorine.
What is the EPA's water treatment system?
The U.S. Environmental Protection Agency (EPA) allows drinking water treatment plants to use chloramine and chlorine to disinfect drinking water. Water system pipes develop a layer of biofilm (slime) that makes killing germs more difficult.
How much chloramine is safe to drink?
Chloramine levels up to 4 milligrams per liter (mg/L) or 4 parts per million (ppm) are considered safe in drinking water. At these levels, harmful health effects are unlikely to occur.
What is the EPA's hotline for chloramine?
EPA provides guidance for local water authorities switching to chloramine on how to minimize lead and copper levels. If you are concerned about lead or copper levels in your household water, call EPA’s Safe Drinking Water Hotline at 800-426-4791 for testing information.
Where is chloramine used?
Chloramine has been used as a drinking water disinfectant in the United States in places like Cleveland, Ohio, Springfield, Illinois, and Lansing, Michigan since 1929. In 1998, an EPA survey estimated 68 million Americans were drinking water disinfected with chloramine.
What is the process of removing salt from groundwater to make fresh water called?
recharge zone. A process that removes the salt from salt water to make fresh water is called. desalination. Water pollution that washes into storm sewers from many places, such as parking lots and lawns, is known as. nonpoint-source.
What are the common features of thermal pollution and artificial eutrophication?
A common feature of thermal pollution and artificial eutrophication is that they both. decrease the amount of oxygen dissolved in water. Water that is found in lakes, rivers, and streams is called. surface water.
When is chlorine added to water?
During pre-chlorination, chlorine is usually added to raw water after screening and before flash mixing. Post-chlorination, in contrast, is often the last stage in the treatment process. After flowing through the filter, water is chlorinated and stored in the clear water reservoir to allow a sufficient contact time for the chlorine to act.
What is the purpose of chlorination?
Chlorination is the application of chlorine to the water for the purpose of disinfection . But the chlorination can also be used for taste and odor control, iron and manganese removal, and to remove some gases such as ammonia and hydrogen sulfide. Chlorination is currently the most frequently used form of disinfection in the water treatment field. However, other disinfection processes have been developed. Like several other water treatment processes, chlorination can be used as a pretreatment process (pre-chlorination) or as the final treatment of water (post -chlorination).
What is the term for adding chlorine to water after the break point?
The addition of chlorine beyond break point is called break point chlorination . The residual of free chlorine, appearing after break point, is not usually removed except by sun light and therefore, it takes care of the future recontamination of water.
What is pre chlorine?
Pre-chlorination is the addition of chlorine to the raw water prior to treatment to produce residual chlorine after meeting chlorine demand. The residual chlorine is useful in several stages of the reatment process – aiding in coagulation, controlling algae problems in sedimentation basins, reducing odor problems, and controlling mud-ball formation in filters. In addition, the chlorine has a much longer contact time when added at the beginning of the treatment process, so prechlorination increases safety in disinfecting heavily contaminated water.
What does de chlorine mean?
De-chlorination means removing the chlorine from the water. This is generally required when super-chlorination has been practiced. The de-chlorination process may either be carried out to such an extent that sufficient residual chlorine of 0.1 to 0.2 mg/L only remains in water after de-chlorination.
What happens when you add chlorine to water?
Chlorine added to water first reacts with any iron, manganese or hydrogen sulphide that may be present in water. The entire chlorine added will be utilized in reacting with organic substances (including bacteria). Hence there will not be any residual chlorine (line AB) as initial chlorine demand. When chlorine is further added to water, it reacts ...
Why is pre chlorination always followed by post chlorination?
The pre-chlorination is always followed by post chlorination, so as to ensure final safety of water. Until the middle of the 1970s, water treatment plants typically used both pre-chlorination and post-chlorination.
Do all cities use surface water as a source?
a. All large cities use surface water as a water source.
Is there a relationship between surface and groundwater?
b. There is no relationship between surface and groundwater; they form independently.