Order 4 disinfectants in increasing order of their disinfection power?
NCl3 < Monochloramine < HOCl < Ozone
Ranking Disinfectant Power: Ozone, HOCl, Monochloramine & NCl3
This question asks us to arrange four common disinfectants based on their effectiveness in killing microorganisms, from least effective to most effective. The disinfectants are Ozone (O3), Hypochlorous acid (HOCl), Monochloramine (NH2Cl), and Nitrogen trichloride (NCl3).
Understanding Disinfection Power
Disinfection power refers to how well a chemical agent can inactivate or kill harmful microorganisms like bacteria, viruses, and protozoa. Factors influencing this include the chemical's properties, concentration, contact time, temperature, and the type of microorganism.
Comparing the Disinfectants
Let's look at the relative strengths:
- Ozone (O3): Ozone is a very powerful oxidizing agent and one of the strongest disinfectants available. It acts rapidly and is effective against a wide range of pathogens, including Cryptosporidium, which is resistant to chlorine-based disinfectants.
- Hypochlorous Acid (HOCl): HOCl is the active disinfecting form of chlorine in water, especially at lower pH levels. It is a strong and widely used disinfectant, effective against most common pathogens.
- Monochloramine (NH2Cl): Monochloramine is formed when ammonia reacts with chlorine. While it is a less potent disinfectant than HOCl and requires longer contact times, it is more stable and provides a longer-lasting residual effect in water distribution systems.
- Nitrogen Trichloride (NCl3): NCl3 is a chemical compound sometimes formed during water disinfection processes involving high ammonia concentrations. While it possesses oxidizing properties and can act as a disinfectant, its efficacy is generally considered lower or less predictable compared to ozone and HOCl. In comparative rankings, it's often placed below these stronger agents.
Ordering Disinfectants by Power
Based on their general efficacy and common usage patterns in disinfection, the increasing order of disinfection power is established as follows:
Nitrogen trichloride (NCl3) exhibits the least disinfection power among the options, followed by Monochloramine, which is less potent than Hypochlorous acid (HOCl). Ozone (O3) is recognized as the most powerful disinfectant in this list.
Therefore, the correct order from least to most powerful is:
NCl3 < Monochloramine < HOCl < Ozone
Important Questions from Disinfection
The dose of chlorination, beyond which any further addition of chlorine will appear as free residual chlorine, is known as:
A city that has a supply of 15000 cubic meters of water per day is treated with a chlorine dosage of 0.5 ppm. For this purpose, the requirement of 25% bleaching powder per day would be.
Which one of the following is used to kill the pathogens?
An experiment shows that a concentration of 0.1 g/m3 of free available chlorine yield a 99% kill of bacteria in 8 minutes. Calculate disinfection rate constant (1 /min)? Assume that Chick's Law and Watson's Law hold with n = 1.
The process which involves chlorination beyond break point chlorination, is known as
