The indicators of water quality testing can be judged by sight and smell

Chromaticity: If the chromaticity of drinking water is greater than 15 degrees, most people can perceive it, and people feel disgusted when it is greater than 30 degrees. The standard stipulates that the chromaticity of drinking water should not exceed 15 degrees.

Turbidity: It is used to indicate the degree of clarity and turbidity of water. It is one of the most important indicators to measure the quality of water quality. It is also an important basis for evaluating the purification efficiency of water treatment equipment and evaluating the state of water treatment technology. The reduction of turbidity means that the content of organic matter, bacteria, virus and other microorganisms in the water body is reduced, which not only improves the disinfection and sterilization effect but also helps to reduce the generation of halogenated organic matter.

Residual chlorine: Residual chlorine refers to the amount of chlorine remaining in the water after the water has been disinfected with chlorine for a certain period of time. The continuous sterilization ability in the water can prevent the self-contamination of the water supply pipeline and ensure the water quality of the water supply.

Chemical oxygen demand: refers to the amount of oxygen required by chemical oxidants to oxidize organic pollutants in water. The higher the chemical oxygen consumption, the more organic pollutants in the water. The organic pollutants in the water mainly come from the discharge of domestic sewage or industrial waste water. It is produced by the decay and decomposition of animals and plants into the water body.

Total coliform bacteria: It is an indicator of fecal pollution, and the detection of it can indicate whether there is fecal pollution in the water and the degree of pollution. In the process of water purification, after disinfection treatment, if the total coliform index can meet the requirements of drinking water standards, it means that other pathogenic bacteria are basically killed. The standard is no more than 3/L in the test.

Heat-resistant coliforms: It reflects the degree of food contamination by human and animal feces more closely than coliforms, and is also an indicator of fecal contamination in water bodies. Bacteria contained in water come from air, soil, sewage, garbage and dead animals and plants. There are various types of bacteria in water, including pathogenic bacteria. my country stipulates that the standard of drinking water is that the total number of bacteria in 1ml of water does not exceed 100.

Odor and Odor: Odor is one of the must-test items for testing raw water and treated water. Water odor is mainly caused by the presence of organic matter, which may be caused by increased biological activity or industrial pollution. The odor in water is mainly from domestic sewage and Contaminants in industrial wastewater. Decomposition of natural substances or microbial activity associated therewith.

Changes in the normal odor of public water supplies may be a signal of changes in raw water quality or inadequate water treatment. Odorless and tasteless water is not guaranteed to be safe, but it is good for the drinker's trust in water quality. Because most odors are too complex and the detectable concentration is too low, it is difficult to separate and identify odor-producing substances. Testing odor is also a means of evaluating water treatment effects and tracking pollution sources.