Conventional water quality testing method
With the rapid development of modern industrial technology, pollution problems have become more and more prominent, and environmental protection issues have received great attention from the whole society.
Water is an important resource of the natural environment, which is closely related to our life, but its pollution problem is becoming more and more serious. Conventional water quality testing methods are gradually emerging and widely used. Conventional water quality testing is generally carried out on-site water quality testing equipment, and the testing equipment requires inspection data on-site and reflection speed, easy to use and convenient to carry. At present, water quality testing is one of the main means of water conservation and pollution control.
Water quality testing is mostly used for industrial water, water treatment and drinking water. Routine water quality testing not only provides us with water safety, but also provides scientific basis and guidance for environmental protection and production quality.
The conventional water quality testing methods are as follows:
1.Color and transparency
The water body displays various colors depending on the composition of the pollutants. Conventional water quality testing mainly estimates the type and quantity of impurities in the water based on the color of the water. For example, clay makes the water yellow, sulfur precipitated by sulfuric acid can make the water blue, and various algae are yellow-green and brown. The transparency of the water quality indicates the extent to which impurities in the water block the transparent light. If the disc is etched through the water layer on the one hand, white or black, and the depth of the disc is adjusted until it can be seen, the depth and position of the disc at this time indicate its transparency. Therefore, the state of water quality can be judged by the transparency indicated.
The trace components of water quality are mainly analyzed by water quality testing instruments. Among them, mainly include atomic absorption spectroscopy, gas and liquid chromatography, plasma emission spectroscopy. It is very important for the system to understand the meaning of various water quality indicators. For any aquatic ecosystem environment, the results of testing and analysis are carried out through strictly selected indicators. In short, trace components of water quality must be tested by these instruments.
3.Redox and electrochemical methods
The most typical of the conventional water quality testing methods is the redox and electrochemical methods. There are water conductivity, oxidation and reduction potentials, and various indicators of ion-selective electrodes including PH, such as many metal ions. Mostly the amount of dissolved and the chloride ion content are indicators.
4.Heating and oxidizing agent decomposition method
This method mainly uses an organic compound containing a living body, a content of carbon dioxide generated at the time of decomposition, or a content of oxygen consumed during decomposition, as an indicator of water quality detection.
5.Temperature and neutralization method
Temperature is one of the most commonly used water quality testing methods. Because of the many physical characteristics of water and the chemical processes in the water, it is closely related to temperature. The temperature of the water source is different, but the temperature of the surface is related to the local climatic conditions. The range of variation is 1-30 °C, and the temperature of seawater varies from 2-30 °C. The neutralization method mainly includes the acidity or alkalinity of the water. Conduct water quality testing.
Most of the substances contained in natural water are solid substances. It is often necessary to use the analyzer content as a direct water quality testing standard. Various solid content standards can be classified into three categories: one, suspended solids. The mass of solids remaining after drying the residue after filtration of the water sample, that is, the content of suspended matter. Second, the total solids. The water sample can evaporate and dry the total amount of solid matter remaining at a certain temperature, which can be used as one of the conventional water quality testing standards. Third, statistical solids. The soluble solids mainly include organic substances of honor water and inorganic salts, and the total solid content is the sum of suspended solids and dissolved solids. In addition, the determination of various solid contents was carried out by weight, and the effect of the evaporation drying temperature on the results was very large. Therefore, under normal circumstances, satisfactory water quality test results cannot be obtained, and the results of the water quality test method are not accurate enough.