- Technical requirements for environmental dredging
Environmental dredging aims at removing polluted bottom mud in water bodies such as oceans, lakes, and rivers, strictly controlling the precision of dredging, focusing on preventing the re-diffusion of polluted bottom mud in the dredging process and the leakage of polluted bottom mud in the transportation process.
The key technologies of environmental dredging include the following: dredging scale design, dredging method of contaminated sediment, accurate positioning of dredging space, residual water treatment after dredging, storage, and disposal of dredged sediment, etc.
- Selection of environmental dredging equipment
Choose what kind of dredging equipment is directly related to the type of dredging and technology: (1) different degree of the interference of sediment dredging equipment, diffusion and drain leakage prevention mechanism and characteristics also vary, inhaled concentration is different, therefore, adopt not with dredging equipment in the process of dredging, areas of environmental pollution is also different; (2) to choose what kind of environmental protection dredging equipment, generally need to consider the control technology of the equipment, because environmental protection dredging of space positioning and dig deep control with high accuracy, dredging section should be close to surface sediment pollution, otherwise it will cause secondary pollution, should try to avoid and reduce the overbreak and leakage situation.
- Transport technology of dredged sediment
In the process of environmental dredging, a suitable storage site for contaminated sediment should be selected according to the requirements, and then the cleaned contaminated sediment should be transported to the selected site. Generally speaking, there is a certain distance between the pollutant storage yard and the construction area, which may cause secondary pollution along the conveying process, which should be avoided as far as possible. Therefore, how to solve the problem of secondary pollution in the process of dredging is the key technology for the transportation of contaminated sediment in the process of environmental protection dredging.
- Contaminated sediment treatment technology
In the process of dredging, the polluted sediments removed from rivers, lakes, and coastal areas of the ocean contain a large number of pollutants that may be harmful to the environment. They cannot be directly discharged into the water body of the outlying area or stored in the storage space of the land area. In strict accordance with relevant regulations, an ecological risk assessment should be carried out for contaminated sediment, and appropriate treatment plans should be made according to the requirements for the harmfulness and harm range of sediment pollution, so as to avoid the pollution and harm to the surrounding water and land environment.
- Engineering features of environmental dredging
Due to different dredging purposes, environmental dredging is different from conventional dredging, which is mainly for dredging channels and increasing storage capacity. Because the purpose of environmental dredging is different from that of normal dredging, there are many technical characteristics of environmental dredging.
Environmental protection dredging construction has the following characteristics: dredging engineering amount is relatively small; The content of pollutants in dredged sediment is high. The boundary, depth, and elevation of dredging should be determined according to the distribution of pollutants. Avoid suspension diffusion during dredging; Dredged soil is relatively soft; Environmental dredging is generally non-repetitive (unless secondary pollution is generated).
These characteristics of environmental dredging determine that environmental dredging has a higher requirement for precision, which needs to be carried out in a more serious manner. These technical characteristics of environmental protection dredging also challenge dredging equipment and technology, which require strict control of the precision of environmental protection dredging in the construction process.