What is the equivalent concentration of 1 mg/l?

To understand why 1 mg/l is equivalent to 1 ppm, it’s essential to grasp the definitions and relationships between these units of concentration.

Milligrams per liter (mg/l) measures the mass of a substance in milliliters of water. Parts per million (ppm) is a term often used interchangeably with mg/l in the context of water quality, especially when the density of water is considered to be approximately 1 g/ml. This means that 1 mg/l of a substance in water equates to 1 part of that substance per million parts of water, as there are 1,000,000 milligrams in a liter of water (1 kilogram). Therefore, 1 mg/l directly translates to 1 ppm in water, making this answer correct.

In contrast, the other options refer to different conversions. For instance, 100 ppb (parts per billion) represents a much smaller concentration, which cannot represent 1 mg/l accurately. Similarly, 10,000 ppb translates to 10 mg/l, and 100,000 mg/l denotes an exceedingly high concentration that is far from the 1 mg/l figure provided. Therefore, 1 mg/l effectively equals 1 ppm under typical conditions in water treatment