Water treatment methods and principles

Classification of wastewater treatment methods:
The task of wastewater treatment is to use various technical measures to separate the various forms of pollutants contained in the wastewater or decompose and convert them into harmless and stable substances to purify the wastewater.
Modern wastewater treatment technology can be divided into physical method, chemical method and biological method according to its principle of action and the objects to be removed. Physical method uses physical action to separate pollutants in the floating state of wastewater without changing the chemical properties of the water during the treatment process. .Treatment processes such as grid, precipitation, air flotation, filtration, reverse osmosis, centrifugation, evaporation, crystallization, etc. are all physical methods.
The chemical method is to add certain chemical substances to the wastewater, and use chemical reactions to separate, transform, destroy or recover the pollutants in the wastewater, and convert them into harmless substances such as coagulation, neutralization, oxygen reduction, adsorption, ions Treatment processes such as exchange method, membrane separation, steam stripping, and extraction are all chemical methods.
Biological method is to use the metabolic function of microorganisms in water to degrade organic matter in dissolved and colloidal state of water and wastewater, and convert it into stable and harmless substances, so that wastewater can be purified, such as activated sludge method, biofilm method, and natural biological treatment. Method and anaerobic biological treatment method are all biological methods.