The Role of Chlorine and Chloramine in Disinfection and Removal through Reverse Osmosis
The Role of Chlorine and Chloramine in Disinfection and Removal through Reverse Osmosis
To ensure the purity and safety of water sources, chlorine and chloramine are often added as disinfectants in water treatment to eliminate harmful pathogens and bacteria. Although these chemicals are necessary for disinfection, they can have undesirable effects on both water quality and health.
Understanding the process of adding disinfectants to a water supply can provide better insights into effective removal methods. Reverse osmosis (RO) systems are particularly effective not only in removing chlorine and chloramine from the water but also in eliminating the trihalomethanes (THMs) and haloacetic acids (HAAs), byproducts formed during disinfection with chlorine and chloramine.
What is Chlorine and Why Add it to Water?
Chlorine is a naturally occurring element widely used as a disinfectant in public water supplies. The primary reason for adding chlorine to the water supply is to kill harmful microorganisms and prevent the spread of diseases such as cholera, dysentery, and typhoid. It acts quickly to neutralize bacteria and viruses, making it one of the most cost-effective and widely used methods for ensuring the microbial safety of drinking water.
The U.S. Environmental Protection Agency (EPA) regulates that the maximum residual disinfectant level of chlorine in drinking water should not exceed 4 parts per million (ppm). This initial high concentration is essential to ensure that the water is adequately disinfected as it leaves the treatment facility.
As water travels through the distribution system—comprising pipes, reservoirs, and storage tanks—chlorine levels gradually decrease. This reduction occurs due to several factors:
- Reaction with Organic Matter: Chlorine reacts with organic material present in the water or in the pipes, which reduces its concentration.
- Wall Reaction: Chlorine can react with the walls of the pipes, especially if they are old or made of materials that catalyze chlorine decay.
- Dilution and Leakage: Water may dilute with other water sources, or leakage can occur, which also affects chlorine concentration
Despite the reduction, it’s crucial that the chlorine level does not fall below a certain minimum—typically around 1 ppm by the time it reaches the consumer. This minimum level is necessary to ensure that the water remains safe and free from microbial contamination throughout its journey in the distribution system.
What is Chloramine?
Chloramine is a compound formed by the combination of chlorine with ammonia. While similar to chlorine in its disinfectant function, chloramine is often favored because it does not dissipate as quickly as chlorine, therefore providing a longer-lasting disinfectant effect. This makes it effective in maintaining water purity over longer distances within a water distribution system.
Chloramine is a compound formed by the combination of chlorine with ammonia. While similar to chlorine in its disinfectant function, chloramine is often favored because it does not dissipate as quickly as chlorine, therefore providing a longer-lasting disinfectant effect. This makes it effective in maintaining water purity over longer distances within a water distribution system.
The residual level of chloramine necessary to maintain water safety and quality by the time it reaches the consumer is typically around 1 to 2 ppm. This concentration is sufficient to ensure ongoing disinfection without the negative sensory effects (like taste and odor) often associated with higher chlorine levels.
Side Effects of Chlorine and Chloramines
While beneficial for disinfection, chlorine and chloramines can have side effects, including:
- Taste and Odor: Both chemicals can impart an unpleasant taste and odor to water, often described as bleach-like or medicinal.
- Chemical Reactions: Chlorine and Chloramines can react with organic matter in the water to form disinfection byproducts (DBPs) like trihalomethanes (THMs) and haloacetic acids (HAAs), which are linked to health risks such as cancer and reproductive issues.
- Skin and Eye Irritation: High levels of chlorine and chloramines can irritate the skin and eyes, making water uncomfortable for bathing or swimming.
The Role of Reverse Osmosis in Removing Chlorine and Chloramines
Removing excess chlorine and chloramines from drinking water not only improves taste and smell but also reduces exposure to harmful disinfection byproducts. An RO system that uses a carbon filter followed by a reverse osmosis (RO) filter will provide broad-spectrum purification, which is especially beneficial where high-quality drinking water is desired. While activated carbon filters remove chlorine and some of its byproducts, the RO filter will remove up to 99% of dissolved salts (ions), particles, colloids, bacteria, and pyrogens, as well as a wide range of other contaminants like lead, arsenic, and various organic compounds.
Puricom’s reverse osmosis systems offer an effective solution for eliminating these chemicals, safeguarding your health, and enhancing the taste of your water. You can trust Puricom’s expertise to deliver superior water purification technology.