The Formation of Odor in Water

The odor in water is primarily caused by chemical pollutants and algal metabolites. Odor is one of the earliest parameters used to evaluate drinking water quality, belonging to the category of sensory performance indicators. It is also the most direct parameter for assessing the safety of drinking water; odorous water can cause consumers to feel distrust and insecurity about the water quality.

Many chemical pollutants have varying degrees of odor, such as chlorophenols, fluorene, chlorobenzene, and nitro compounds, which directly contribute to the odor. Algal metabolites cause a strong and diverse odor, with geosmin, 2-methyliso-2-oxohydrin (MIB), 3-isopropyl-3-methoxypyrazine (IPMP), 3-isobutyl-3-methoxypyrazine (IBMP), and 2,3,6-trichloroanisole (TCA) being typical strong odor substances. Furthermore, certain water treatment processes can increase odor intensity; for example, prechlorination processes not only fail to reduce odor but can also produce fishy and pungent smells.