1, pollution of organic wastewater and inorganic wastewater containing non-toxic substances. Although some pollutants are non-toxic, they are harmful to water because of their large quantity or high concentration. For example, when the organic matter discharged into the water body exceeds the allowable amount, anaerobic corruption will occur in the water body; When a large number of inorganic substances flow in, the concentration of salts in water will increase, which will lead to the change of osmotic pressure and adversely affect organisms (animals, plants and microorganisms).

2. Pollution of organic wastewater and inorganic wastewater containing toxic substances. Such as cyanide, phenol and other acute toxic substances, heavy metals, carcinogens and other chronic toxic substances. Poisoning methods include contact poisoning (mainly neurotoxicity), food poisoning and erosive poisoning.

3. Wastewater pollution containing a large amount of insoluble suspended matter. For example, cellulose from pulp and fiber industries, fine dust from coal preparation and mineral processing, and lime sand from ceramics and quarrying industries. Some of these substances are deposited on the bottom of the water to form "toxic mud", and there are many examples of poisoning incidents. If it is organic, it will rot and make the water anaerobic. These substances can also block the gills of fish in the water, causing difficulty in breathing and destroying spawning grounds. For more relevant technical documents, please visit//www.dowwater.com.

4. Pollution caused by oily wastewater. Oil stains floating on the water will not only damage the appearance, but also give off an unpleasant smell. Oil with a low ignition point also poses a risk of fire. Animal and vegetable oils are corrosive and will consume dissolved oxygen in water.

5. Pollution caused by high turbidity and high chroma wastewater. It causes insufficient luminous flux and affects the growth and reproduction of organisms.

6. Acidic and alkaline wastewater pollution. In addition to being harmful to organisms, it will also damage equipment and equipment.

7. Pollution caused by wastewater containing various pollutants. Chemical reactions will occur between various substances, or under the action of natural light and oxygen, chemical reactions will occur to produce harmful substances. For example, sodium sulfide and sulfuric acid produce hydrogen sulfide, and ferrocyanide produces cyanide through photolysis.

8, industrial wastewater containing nitrogen, phosphorus and other pollution. In closed waters such as lakes, the inflow of wastewater containing nitrogen and phosphorus will cause abnormal reproduction of aquatic organisms such as algae and make the water eutrophication.