Water treatment is the process of improving water quality through physical, chemical or biological methods. The goal of water treatment is water that does not meet the quality requirements. Human beings have treated water for many years. Water treatment methods include physical water treatment and chemical water treatment.

          The physical method includes filtering using various filter media with different pore sizes. In addition, adsorption method and sealing method are also used. Remove impurities from water by adsorption or barrier. The more important adsorption method is activated carbon adsorption. The blocking method includes passing water through the filter material. Prevent large impurities from passing through, so as to obtain clean water.

          In addition, the physical method also includes precipitation method. It allows impurities with lower specific gravity to float on the water. Or let impurities with higher specific gravity precipitate below. Get clean water

         Chemical method uses various water treatment chemicals to convert impurities into substances less harmful to human body. Or use water treatment chemicals to concentrate impurities. The oldest chemical water treatment method should be alum. Add alum to the water. And after collecting impurities in water, the volume increases. And impurities can be removed by filtration.

         The minimum standards for drinking water shall be formulated by the environmental protection department. Industrial water has its own requirements. The physical property of water is the basic standard to judge the water quality. Such as temperature, color, transparency, smell, taste, etc. The chemical property of water is also an important index to judge the water quality. Such as pH value, dissolved solid concentration, oxygen content, etc.

         Some natural water has a total dissolved solids concentration of up to 1000 mg / L. Canada requires the concentration of total dissolved solids in drinking water not to exceed 500 mg / L. Many industrial water also requires a concentration of no more than 500 mg / L. 200mg. This kind of industrial water cannot be used casually, even if its physical properties meet the requirements. In addition, the content of radioactive elements in water is also an important feature that must be controlled.

        The purpose of water treatment is to improve the quality of water to a certain level. According to different water treatment methods, there are many types of physical water treatment, chemical water treatment and biological water treatment. According to the purpose of treatment, it mainly includes water supply treatment and wastewater treatment. Water supply treatment includes drinking water treatment and industrial water treatment. Wastewater treatment includes domestic wastewater treatment and industrial wastewater treatment.