Chloride

It is one of the main mineral anions in water and wastewater. One of the most common examples of chloride in water is the salt solution NaCl. This compound is commonly used in chemical processes, the food industry, water purification, and pharmaceuticals. The salty taste of water is caused by this anion and depends on the chemical composition of the water. If it is the sodium cation, some waters containing 250 mg of chloride per liter may have a detectable salty taste. However, if the cations are calcium and magnesium, there is no noticeable salty taste in waters containing 1000 mg/L. High levels of this anion may damage metal pipes and structures, as well as growing plants.

Sources of water chloride

This common anion comes from various sources:

1- Natural sources:

– Geological processes: Rocks and soils contain large amounts of salt, which dissolves in water and enters groundwater and surface waters.

– Saline waters: Seas and oceans are rich in chloride, which enters freshwater through evaporation and precipitation.

– Volcanic activity: Volcanic activity can increase the concentration of this anion in water.

2- Human Resources:

– Urban and industrial wastewater: This wastewater contains a large amount of chloride, which originates from various sources such as washing, chemical industries.

– Saltwater discharge: The discharge of saltwater for industrial and agricultural purposes can cause freshwater pollution.

Duration of sample storage

The maximum time interval between sampling and testing is 28 days.

How to measure

To measure it, we have used the conventional argentometric method and the potassium chromate reagent. In neutral or slightly alkaline solutions, potassium chromate can indicate the end point of the titration. This is because silver chloride precipitates before the formation of red silver chromate.