What are the river sewage treatment methods?

While the industrial revolution brought economic development, people gradually noticed the increasingly serious river pollution. The pollution of the river has gradually affected their work and life. For this reason, people have to pay attention to the treatment of drinking sewage. So what are the treatment methods of river sewage?

Physical Method

Physical methods mainly refer to dredging sediment, mechanical algae removal, diverting water for scouring and water transfer, etc. Dredging contaminated sediment means removing the contaminants from the (river) system. It can greatly reduce the pollution contribution rate of sediment to the overlying water body, thereby improving the water quality. The purpose of water transfer is to introduce clean water sources upstream or near polluted rivers through the regulation of water conservancy facilities (such as gates and pumping stations) to improve the water quality of downstream polluted rivers. Such methods often treat the symptoms rather than the root causes.

Chemical Method 
Chemical methods such as coagulation and precipitation, adding chemical agents to kill algae, adding iron salts to promote the precipitation of phosphorus, adding lime to denitrify and other methods. Studies have shown that this method has a better removal effect on turbidity, COD, SS, and TP, and also has a certain removal effect on TN, heavy metals, etc., and the daily dosage of chemicals is small. However, this method of river sewage treatment is easy to cause secondary pollution.

Ecology--Bio-methods Eco--Bio-methods

Channel Aeration Method

Artificial aeration and reoxygenation refers to the artificial oxygenation of the river in anoxic (or anaerobic) state to enhance the self-purification ability of the river, improve the water quality, and improve or restore the ecological environment of the river. River aeration and reoxygenation generally adopts two forms: fixed oxygenation station and mobile oxygenation platform. The process has the advantages of simple equipment, flexible operation, reliable security, low investment, quick effect, convenient operation, wide adaptability, and no harm to aquatic ecology.

Biofilm Technology 
It means that the microbial population is attached to the surface of some carriers to form a film, and by contacting with sewage. The microorganisms on the biofilm absorb the organic matter in the sewage as nutrients to absorb and assimilate, thereby purifying the sewage. At present, the biofilm technologies commonly used in river sewage treatment mainly include inter-gravel contact oxidation method, contact oxidation method of water holding ditch (canal), biological activated carbon packed column purification method, thin laminar flow method and voltaic flow purification method, which are widely used. It is a contact oxidation method.

Bioremediation Technology
It refers to an engineering technology system that uses microorganisms and other organisms to degrade toxic and harmful pollutants in water or soil into CO2 and water, or convert them into non-toxic and harmless substances. There are two main types of bioremediation technologies used for river sewage treatment. One is to directly add one or more microbial strains that have been cultured and screened to the polluted river water. Tests have shown that the COD removal rate is over 90%. The other is to add microbial growth promoters (nutrients) to polluted river water to promote the growth of "indigenous" microorganisms. After the drug is put in, the growth of pollutant-degrading microorganisms is promoted through the growth-promoting effect. The microorganisms in the river channel change from anaerobic to aerobic, and the organisms change from low to high. , COD drops rapidly, dissolved oxygen rises significantly, and black odor is eliminated. This method has obvious effects on eliminating black and odor in water and increasing dissolved oxygen in water.

Land Treatment Technology
Land treatment technology is an ancient but effective technology for river sewage treatment. It uses the land as a treatment facility, and uses the adsorption, filtration, purification and self-regulation functions of the soil and plant systems to achieve a certain degree of water purification. Foreign practical experience shows that the land treatment system has a good removal effect on organic compounds, especially organic chlorine and ammonia nitrogen.

Aquatic Plant Purification Method
This method is a sewage purification method that makes full use of the natural purification function of aquatic plants. For example, duckweed, reeds in wetlands, etc. are used for purification treatment in a certain water area. However, the discharge of domestic sewage will cause problems such as odor, pests and landscape impact, so the above problems should be comprehensively considered when selecting, such as choosing to plant reeds at the downwind in spring and summer.