What occurs to water quality when chlorine is injected simultaneously with powdered activated carbon (PAC)?

When chlorine is injected alongside powdered activated carbon (PAC), the interaction can lead to the adsorption of chlorine onto the PAC, which may result in the reduction of available chlorine in the water. This means chlorine’s ability to perform disinfection activities is diminished because it may bind to the carbon material rather than remaining in its active form to effectively kill pathogens.

In this scenario, the probability of the chlorine being neutralized, or at least significantly reduced in its concentration, is a key outcome of this simultaneous injection. The adsorption capacity of PAC can lead to a decrease in the effectiveness of chlorine as a disinfectant, thereby impacting the overall disinfection process.

While PAC plays a crucial role in improving taste and odor by adsorbing various contaminants, its simultaneous presence with chlorine does not enhance the disinfection process and can hinder chlorine's effectiveness. Thus, the correct recognition of this interaction supports a deeper understanding of water treatment chemistry and the importance of sequential addition protocols in water treatment systems.