How to design the Chorine dosing pump capacity for STP Plant?
Chlorine is a popular disinfectant used in sewage treatment plants to kill harmful bacteria, viruses, and other pathogens present in wastewater. A properly designed chlorine dosing pump system is essential for effective disinfection of sewage water.
In this blog, we will discuss how to design a chlorine dosing pump capacity for sewage treatment plants and what percentage and type of chlorine to use for disinfection.
Determining the Chlorine Dosing Pump Capacity
The first step in designing a chlorine dosing pump system is to determine the required capacity. The capacity of the system is determined based on the amount of chlorine required to disinfect the wastewater. The chlorine demand of wastewater is influenced by several factors, including the quality of water, temperature, pH, and organic content. The higher the organic content, the more chlorine required for disinfection.
To determine the required chlorine dosage, the following formula can be used:
Chlorine Dosage (mg/L) = (Chlorine Demand (mg/L) + Chlorine Residual (mg/L))/ Contact Time (min)
- Chlorine Demand: The amount of chlorine required to disinfect the wastewater, which is determined by laboratory testing.
- Chlorine Residual: The minimum amount of chlorine required to maintain a residual level of chlorine in the water after disinfection.
- Contact Time: The time for which the wastewater remains in contact with chlorine.
Once the required chlorine dosage is determined, the capacity of the dosing pump can be calculated based on the flow rate of the water.
Chlorine Type and Dosage Percentage:
When it comes to choosing the type of chlorine to use in sewage treatment plants, there are two options available: gas chlorine and sodium hypochlorite.
Gas Chlorine: Gas chlorine is a highly effective disinfectant that is commonly used in large sewage treatment plants. However, it requires special handling and storage equipment, and there is a risk of leaks, which can be dangerous.
Sodium Hypochlorite: Sodium hypochlorite is a liquid form of chlorine that is more commonly used in small to medium-sized sewage treatment plants. It is safer to handle and store than gas chlorine, and it can be easily dosed into the water.
The dosage percentage of chlorine depends on the type of chlorine used, the quality of the water, and the organic content of the wastewater. Generally, the recommended dosage range is between 1 to 5 mg/L for gas chlorine and 5 to 20 mg/L for sodium hypochlorite.
It is important to note that over-dosing or under-dosing of chlorine can be detrimental to the environment and human health. Over-dosing can lead to the formation of harmful disinfection by-products, while under-dosing can result in incomplete disinfection and the spread of waterborne diseases.
Designing an effective chlorine dosing pump system for sewage treatment plants requires careful consideration of several factors, including the chlorine demand of the wastewater, the type of chlorine used, and the required dosage percentage. By following the guidelines discussed in this blog, sewage treatment plant operators can ensure effective disinfection of wastewater and maintain a safe and healthy environment for the community.