Water quality monitoring refers to the monitoring of chemicals, suspended solids, sediment and water ecosystems in water on a regular or irregular basis. Water quality monitoring plays an important role in maintaining the health of the water environment.

For drinking water, if the water contains harmful bacteria, such as injury, cholera, dysentery and other germs, it will spread various diseases. If there is a large number of plankton in the water (such as protozoa, algae, etc.), it will affect the physical properties of the water, and produce odour and water colour.

If the water contains certain mineral salts impurities, can also cause various diseases. If the drinking water contains too much fluoride, it will make the teeth produce mottled, and cause mottled teeth disease, and in serious cases, it can make the teeth completely ulcerated.

As for the sewage discharged from daily life, it will also spread diseases. Therefore, the study of water treatment and the determination of whether the water quality meets the standard of drinking water is an important topic to ensure the health of the people and the construction of the country.

For industrial water, it is necessary to understand who mention the physical properties and chemical composition, because a variety of industrial water not only need enough water, but also due to industrial production for different purposes on the water quality requirements are also different, for example, boiler water can not contain a large number of calcium, magnesium sulphate, otherwise the boiler will produce scale, not only will be consumed too much fuel, but also may cause the boiler to explode, and then again; cooling equipment, cooling water content of feed water has to be determined by a metallurgical plant, and the water quality is also very important.

Cooling equipment in metallurgical plants, the content of feed water has very strict regulations. For industrial water, it is considered whether it affects the quality of the product or tends to damage containers and pipework.

In addition, water quality monitoring can be:
a)Provide data and information for environmental management, environmental science research:

b)Determine the distribution of pollutants in the water body, tracing the source of pollutants, pollution pathways, migration transformation and elimination of the law, predict the trend of water pollution:

c)To determine the impact of water pollution on environmental biology and human health, and to evaluate the effectiveness of the implementation of pollution control measures:

d) To provide data representing the current status of water quality for the evaluation of the environmental quality of water bodies:

e) Explore the causes of pollution, pollution mechanism and various pollutants, further in-depth liver cancer not environment and pollution theory research.

The scope and types of water quality monitoring

The main purpose of water quality testing is to test the composition of water and water quality indicators coincide with the water quality indicators are parameters describing the quality of water, usually with the type of impurities in the water, the composition and the number of said. Water quality indicators of a wide range of items, depending on the use of different and different.

Some of the water quality indicators from the name of the specific impurity components can be seen, such as Hg, Cd, As, small nitrate (AgNo3), oxides, DTT, etc., there are a number of water quality indicators to respond to the common impact of the impurity components of the results, such as alkalinity, hardness, etc.: There are a number of water quality indicators are many polluting impurities of the comprehensive indicators, such as turbidity, BOD, COD, and so on.

Water quality monitoring can be carried out by chemical method, agrochemical method, atomic absorption spectroscopic, ion chromatography, meteorological chromatography and other methods. Among them, the chemical method is still commonly used in routine monitoring of water quality at home and abroad.

The scope of water quality monitoring is very wide, including: uncontaminated and contaminated natural water, such as rivers, streams, lakes, less and groundwater and various industrial drainage. Water quality monitoring sometimes need to carry out the determination of flow rate and flow.