Условие:
The odor of water (putrid, fecal, medicinal, chlorine, oil) indicates the presence of dissolved chemical substances and/or saturation of water with gases of natural and anthropogenic-technogenic origin. Water odor is determined at 20 °C and 60 °C. Water odor is measured in points on a five-point scale (Table 22).
\nTable 22\nScale for Determining Water Odor
\nOdor Intensity | Description of Odor Intensity | Points
---|---|---\nNone | Odor is not perceived | 0\nVery faint | Odor is perceived only in the laboratory by an experienced analyst | 1\nFaint | Odor is perceived if attention is drawn to it at 60 °C | 2\nNoticeable | Odor is easily detected at 20 °C | 3\nDistinct | Odor draws attention and makes the water unpleasant to drink | 4\nVery strong | The odor is so strong that the water is unsuitable for drinking | 5
\nFor drinking water, an odor of no more than 2 points at 20 °C and 60 °C is allowed for centralized water supply systems, and no more than 2-3 points for non-centralized (local) water supply systems. Specific water odors appearing during chlorination should not exceed 1 point.
\nGeneralized indicators.\nThe reaction (pH) of natural water is slightly alkaline, pH = 6–9. pH is determined by the color of moistened litmus paper. Water containing humic acids or contaminated with acidic industrial wastewater has an acidic reaction (pH<7.0, red color). Water contaminated with alkaline industrial wastewater has an alkaline reaction (pH>7.0, blue color).
