Abstract: A complete pretreatment and backwashing system is added on the basis of the original process of sand and stone wastewater treatment. By changing some main design parameters (such as surface hydraulic load, sedimentation time, etc.) and adopting advanced wastewater treatment equipment, the sand and stone wastewater can be discharged up to standard.

At present, the development of hydropower industry in China is advancing by leaps and bounds, but the development of hydropower has caused serious pollution to the environment at the same time, and the ecosystem has also been damaged to varying degrees. Therefore, the development of hydropower at the same time environmental protection will be very important. In fact, wastewater treatment has become one of the important means to protect environment, make full use of water resources and save water. Sand and stone engineering is an necessary part of hydropower engineering. Sand and stone production will produce a large number of wastewater, if the wastewater is directly discharged to nature, it will cause serious pollution to natural water resources, so the sand and stone wastewater must be treated and reused or discharged. However, there is no special design specification for sand and stone wastewater, and the design of sand and stone wastewater treatment still follows the design idea of domestic sewage. There is a great difference between domestic sewage and sand waste water. Therefore, there are still a series of problems in the design of sand and stone wastewater treatment by using the design idea of domestic sewage directly. And these problems will be the urgent problems that we need to solve at present. The advantages of the process: A complete backwashing system and preprocessing technology. The main characteristic of the sand and stone wastewater is the high sand content and less pollution components. It looks easy to treat. But easy hardening mud is a problem that is difficult to successfully deal with the waste water. The main reason for the slit is the high content of powder stone powder, and the strong hydrophobicity of stone powder. Under the action of hydrostatic pressure, if not cleaned up in time, it will form a plate knot easily, which makes the sludge at the bottom of the sedimentation tank difficult to clean and block the pipe. The difficulty of discharging mud will be one of the difficult problems in the treatment of sand and stone wastewater. There are also some designing parameters and whether the selection of technological process is reasonable, which will directly affect the quality of the effluent quality.. These are all problems facing the design of sand and stone wastewater treatment plant at present. So membrane filter press machine is the best choice for the treatment of sand and stone wastewater.