Chlorination

Definition

Chlorination is a chemical process used to disinfect water and wastewater by adding chlorine or chlorine compounds, effectively killing harmful microorganisms. This method is critical in ensuring the safety of treated water and is a vital step in various advanced wastewater treatment processes, including tertiary treatment.

5 Must Know Facts For Your Next Test

1. Chlorination not only kills bacteria and viruses but also helps control algae and odors in treated wastewater.
2. The effectiveness of chlorination depends on factors like pH, temperature, contact time, and the presence of organic matter.
3. Chlorination can lead to the formation of disinfection byproducts (DBPs), which can be harmful to human health; thus, monitoring is essential.
4. In advanced wastewater treatment, chlorination is often followed by dechlorination to remove excess chlorine before the effluent is released or reused.
5. Chlorination plays a role in combating antibiotic-resistant bacteria by effectively reducing their populations in wastewater before it enters the environment.

Review Questions

• How does chlorination contribute to the overall effectiveness of advanced wastewater treatment processes?
  • Chlorination enhances the effectiveness of advanced wastewater treatment by ensuring that harmful microorganisms are effectively killed, thereby improving the safety of the treated effluent. This process plays a crucial role in tertiary treatment stages, where the focus is on achieving high levels of disinfection before water is reused or released into the environment. By utilizing chlorination, treatment facilities can mitigate health risks associated with pathogens and maintain compliance with regulatory standards for water quality.
• What are the design considerations for implementing chlorination in tertiary treatment systems?
  • When designing chlorination systems for tertiary treatment, several considerations must be taken into account, including determining the appropriate dosage of chlorine needed for effective disinfection while minimizing the formation of disinfection byproducts. Engineers must also assess factors such as contact time, retention basin size, and monitoring systems for residual chlorine levels. Additionally, plans for dechlorination processes must be included to ensure that treated water does not contain harmful levels of chlorine when released or reused.
• Evaluate the impact of chlorination on antibiotic-resistant bacteria during wastewater treatment and its implications for public health.
  • Chlorination significantly impacts antibiotic-resistant bacteria during wastewater treatment by effectively reducing their populations and preventing their spread into the environment. However, some resistant strains may survive chlorination, raising concerns about their potential to re-enter ecosystems and contribute to public health challenges. Understanding the effectiveness of chlorination against these bacteria is essential for developing strategies to combat antibiotic resistance. Therefore, ongoing research into optimizing chlorination processes and exploring alternative disinfection methods is crucial to ensure safe water reclamation and protect public health.

Related terms

Disinfection: The process of eliminating or reducing harmful microorganisms from a surface or medium, often using chemicals like chlorine or ultraviolet light.

Chlorine Dioxide: A powerful disinfectant used in water treatment that is more effective than chlorine against certain pathogens and produces fewer harmful byproducts.

Residual Chlorine: The amount of chlorine that remains in the water after disinfection, which helps maintain microbial safety as water is distributed.