China's industrialization is in the stage of rapid development. In this stage, environmental management, especially water environmental management is particularly important. Water quality in the river will directly affect people's living environment and quality of life. Due to the serious pollution of urban water environment in China, the water bodies in urban river courses are mostly polluted by organic pollutants, nitrogen, phosphorus and other pollutants. The management of urban black and smelly river will be the key environmental problem to be solved in the future.
I. the formation of black and smelly urban river courses
"Black odor" is considered as a biochemical phenomenon of anaerobic decomposition of organic pollutants in water and an extreme phenomenon of organic pollution in water. Due to the excessive content of organic pollutants, nitrogen and phosphorus in the water, water anoxia, organic corruption. Long-term exposure poses a serious threat to the health of urban residents and urban ecological security. After a large amount of organic matter enters the water body, it destroys the degradation and purification system of the water body itself. After the process of decomposition and corruption, smelly substances such as humus are deposited at the bottom of the river. Volatile and irritating gases, such as hydrogen sulfide and methane, escape from the water surface. The heavy metal iron, manganese and other pollutants discharged into the water form sulfide with sulfur in the water, forming a large number of charged colloidal black suspended particles. Causes of black and smelly river: organic matter, sediment, water temperature, DO, etc.
Two, urban river black and smelly control technology
1. Artificial aeration
One of the main causes of black and smelly water is the imbalance of oxygen supply and consumption caused by eutrophication and a large amount of humus. Artificial aeration reoxygenation is an effective measure to control black and smelly river. In 2000, aerated reoxygenation technology was applied in China. Artificial aeration reoxygenation technology is mainly used to increase the content of DO in water body, strengthen the function of water body self-purification and promote the restoration of water body ecosystem by adding oxygen to the black and smelly river. According to the actual treatment of environmental factors, artificial aeration reoxygenation can be generally divided into three categories: air diffusion aeration, water surface to brush aeration, ship borne mobile aeration.
2. Dredge the bottom mud
Sediment dredging is the source of pollutants in river courses. Sediment dredging can permanently remove sediment from river courses and lakes. Therefore, sediment dredging is a widely used technical method to control black and smelly river courses. The main dredging methods include dry bed cleaning, grab dredger and hydraulic flushing. Through the above methods to increase the dredging of port channels and other channels, increase the navigable depth; To reach water storage, drainage flood discharge, adjust the water system, improve the flow conditions; Remove pollutants from the surface sediments of lakes and rivers, improve water bodies, and improve flood discharge and self-purification functions of water bodies.
3. Strengthen flocculation
Enhanced flocculation is a chemical method of urban river black smelly governance, through the use of chemicals, iron and aluminium salt with oxidant, such as hydrogen peroxide and precipitant limestone, remove suspended material in the black smelly river and soluble nitrogen, phosphorus, decrease chroma of the water, mainly used for the improvement of the visual senses, multi-purpose at black smelly river management part of the link. Through the action of chemical flocculation, water quality can be improved greatly in a short time.
4. Biological governance and ecological restoration
Biological ecological method can improve river water quality fundamentally and effectively for a long time. The self-purification and restoration of natural water bodies are mainly the absorption and transformation of water pollutants, eutrophicated nitrogen and phosphorus through the action of microorganisms in water bodies. Reconstructing water microbial system is an effective way to solve the problem of black and smelly urban watercourses. Biological ecological methods mainly include microbial enhancement technology, biofilm technology, plant essence technology and biological ecological purification technology.
Application case of submerged blower
Four, the advantages of submerged water fan
Submersible blower is an upgraded version of roots blower, which has certain advantages in sewage treatment and river treatment:
(1) lower energy consumption:
The submerged blower can reduce the heat dissipation hole of the bearing seat, reduce the pressure loss and improve the efficiency of the whole machine.
When the blower is in operation, the sound is refracted into the water at the interface between air and water, but not into the air.
(3) do not need to make room:
Submerged roots blower in water, solid do not need another production room, at the same time the blower placed in the tank, do not take up space, so can effectively use the space.
(4) life extension and ultra-long maintenance cycle:
Because the fan is immersed in water, it has a good heat dissipation effect, reduces the loss of internal wearing parts, and thus prolongs the service life and the maintenance cycle is 2 years.
It is an urgent problem to control the black and foul smell in urban watercourses. Urban river courses are the source of water pollution. With the increase of urban population, it is urgent to control the black and smelly urban river courses.