3.2 Explanation of technology for controlling black and odorous water pollution in rivers
3.2.1 Sediment Dredging Technology
One of the main sources of pollutants is sediment. Therefore, the scientific use of sediment dredging technology, such as hydraulic siltation, grab dredging, and riverbed dry cleaning, can effectively avoid the occurrence of black and stinky water bodies. During sediment dredging, the sludge containing a variety of organic pollutants, phosphorus and nitrogen is scientifically cleaned, which can effectively prevent black and odorous water bodies and avoid secondary pollution.
3.2.2 Artificial aeration
As aquatic plants and humus increase in the water environment, the oxygen content will decrease. At this time, the oxygen supply will be unbalanced, which will lead to the black and smelly water phenomenon. Based on this, artificial aeration is used to increase the oxygen content in the river water and improve the self-purification ability of the water body. , which plays a positive role in controlling black and smelly water bodies. Generally, artificial aeration and re-ignition can be roughly divided into three categories: ① Explosion aeration and diffusion aeration. It is often used when there is less pollution and the equipment is running well; ② Rotating brush exposure on the water surface. Suitable for application under serious pollution conditions; ③Mobile aeration of ships. This method is more advantageous when it comes to severe water pollution conditions, especially in harsh environmental scenarios. However, it should be noted that this method consumes a lot of power, is more expensive, and will have an impact on the environment. It needs to be applied based on actual comprehensive considerations.
3.2.3 Biological treatment and remediation
The purpose of cleaning and restoration is achieved with the help of the self-purification ability of water bodies. It mainly uses microorganisms in water to absorb and transform pollutants. Currently common biological treatment methods include biofilm technology, microbial enrichment technology, etc. This method is low-cost, easy to operate and does not cause secondary pollution. Bioremediation technology is mainly based on the construction wetland method, using sand and other non-polluting methods. Materials are used as the basis and mixed according to a certain proportion to artificially construct a wetland system, which is also extremely beneficial to repairing the water environment.
3.2.4 Living water hydration technology
In order to improve the self-purification ability of the water environment, ensuring the fluidity of the water body is the foundation. The reason why most rivers currently have black and smelly water bodies is related to the weak self-purification ability of the rivers and the rivers becoming stagnant water. Based on this, it is feasible to pay attention to the cleanliness of water sources, ensure the fluidity of water areas, and improve water quality.
3.2.5 Water purification
This method can achieve the goal through various methods such as physical, chemical, biological and ecological methods. The artificial aeration method highlighted above is one of the physical purification methods. Chemical methods mainly add substances that will not cause pollution again into the water body, such as iron salts, aluminum salts and other coagulants, which react with phosphorus in the water body pollution to form precipitation and reduce the presence of pollutants in it. Biological methods mainly include aquatic vegetation restoration technology, etc., using plants to purify the air, increase water depth illumination, or interfere with the growth of some specific plants. This is also a feasible measure to prevent the occurrence of black and smelly water bodies. At the same time, with the development of my country's advanced technology, more and more new technologies have become available. For example, ecological floating bed technology is a technology with a wide range of applications. It can not only exert environmental governance, but also has ecological restoration capabilities. The application principle is to transplant plants grown on land to the water surface with the help of soilless cultivation technology, which not only adds ornamental value to the water environment, but also achieves the purpose of water management. However, it should be noted that this technology is suitable for applications where the flow rate is gentle and the total volume is constant. In small and medium-sized watershed scenarios.
