Which statement correctly describes chlorination and UV disinfection as common plant disinfection methods?

Which statement correctly describes chlorination and UV disinfection as common plant disinfection methods?

• A. Chlorination uses ultraviolet light; UV uses chlorine gas.
• B. Chlorination uses chlorine or chloramines, UV uses ultraviolet light.
• C. Chlorination uses ozone; UV uses chlorine.
• D. Chlorination uses heat; UV uses chemical disinfectants.

Answer: (B)

Chlorination and UV disinfection rely on different mechanisms to inactivate pathogens. Chlorination uses chemical disinfectants—chlorine gas, hypochlorite, or chloramines—to kill or inactivate microorganisms, and it can leave a residual disinfectant that continues to act after treatment. UV disinfection uses ultraviolet light, typically UV-C, to damage microbial DNA so the organisms can’t reproduce. This combination of mechanism and agents is what makes the statement correct: chlorine or chloramines for chlorination, ultraviolet light for UV disinfection. The other ideas don’t fit how these methods work: ultraviolet light isn’t chlorine gas, chlorine isn’t used for UV, and chlorination isn’t done with heat or ozone. UV treatment also depends on water clarity because turbidity can shield pathogens, while chlorination provides ongoing disinfection due to the residual.

Chlorination and UV disinfection rely on different mechanisms to inactivate pathogens. Chlorination uses chemical disinfectants—chlorine gas, hypochlorite, or chloramines—to kill or inactivate microorganisms, and it can leave a residual disinfectant that continues to act after treatment. UV disinfection uses ultraviolet light, typically UV-C, to damage microbial DNA so the organisms can’t reproduce. This combination of mechanism and agents is what makes the statement correct: chlorine or chloramines for chlorination, ultraviolet light for UV disinfection.

The other ideas don’t fit how these methods work: ultraviolet light isn’t chlorine gas, chlorine isn’t used for UV, and chlorination isn’t done with heat or ozone. UV treatment also depends on water clarity because turbidity can shield pathogens, while chlorination provides ongoing disinfection due to the residual.