Why should the rural sewage treatment project adapt measures to local conditions?
There are great differences in sewage conditions in different regions in China, so rural sewage treatment projects need to make reasonable arrangements according to the actual situation of different locations.
There are some differences in the water quality between the north and south of China, while the north is hard and soft in the south. The reason is that the north has less rainfall and the evaporation is large, while the south rainfall is heavy, and the minerals in the water are washed by the rain, resulting in soft water quality. The amount of rural sewage produced in different regions of China is quite different, and the eastern region accounts for about half of the national production. Both the central and western regions grow rapidly, and the growth rate is higher than the national average level.
The main difficulty of sewage treatment in northern China is the lack of supporting pipe network. Some newly built sewage treatment plants will focus on the main pipe, many of the main pipe and the main pipe between the supporting equipment is not high attention. There are also some old communities of the rain and sewage pipe network mixed mixed phenomenon, domestic sewage directly into the rainwater pipe, even if the transformation can not meet the common discharge standard of rainwater and domestic sewage. Restricted by the local economic development level and other human factors. Some production enterprises do not want to invest too much in sewage treatment, and the drive of enterprises leads to industrial wastewater can not be treated effectively. At present, many industrial wastewater treatment list is not large enough, the area is not concentrated enough, and the equipment and personnel input is difficult to form a scale.
The difficulty in sewage treatment in southern China is the different climate. The climate in southern China is affected by the seasonal differences, which affects the selection of rural domestic sewage treatment methods, processes and the design of pollutant control scheme. The composition of rural domestic sewage is complex. Although the pollution concentration of domestic sewage is low, the fluctuation is large, which is a difficult problem for the assessment of the pollution load of treating domestic sewage. In addition, the choice of sewage treatment technology is also closely related to the degree of local importance and economic strength. Temperature will also have a great impact on sewage treatment. In the high temperature environment, the microbial activity in sewage intensifies, resulting in the improvement of biochemical reaction speed, leading to the stop of aerobic digestion and nitrification. At the same time, this may also be one of the important reasons for the occurrence of water pollution such as cyanobacteria bloom. High temperature weather will lead to the acceleration of biological reproduction in the sludge and the enhancement of its own respiration, resulting in the increase of sludge viscosity and hydraulic resistance. The sludge particles after degradation reaction will also become smaller due to the increase of nitrification process and suspended in the sewage, increasing the load of the sedimentation tank and filter. Some sewage treatment systems in the summer high temperature weather, may appear "instability phenomenon", such as COD, ammonia nitrogen, phosphorus and other indicators in the effluent exceed the standard, which is related to the abnormal microbial metabolism in the biochemical reaction.
Sewage treatment equipment to achieve local conditions, the need to consider the following aspects:
１、Water quality of sewage: The water quality of sewage may be different in different regions. For example, the composition and concentrations of industrial and domestic wastewater can vary widely. Therefore, it is necessary to determine the type and design parameters of sewage treatment equipment according to the water quality of sewage.
2、Local geographical environment: Different regions may have different geographical environments, including climate, terrain, soil, etc. This will affect the construction and operation of sewage treatment equipment. For example, in cold areas, insulation measures need to be considered to ensure that sewage treatment equipment operates properly at low temperatures.
3、Local economic conditions: the construction and operation of sewage treatment equipment need a certain amount of capital investment. Therefore, the need to determine the equipment selection and scale according to the local economic conditions. If the local economic conditions are limited, you can choose the equipment with a relatively low price, but the performance and quality of the equipment need to be considered.
4、Energy efficiency of equipment: The energy consumption of sewage treatment equipment is also a factor to be considered. If local energy prices are high, choose energy efficient equipment.
5、Maintainability of equipment: the maintenance and management of sewage treatment equipment is an important link. Therefore, the maintainability and reliability of the equipment need to be considered. Without local technology and management experience, choose equipment that is easy to maintain and manage. In short, adjusting measures to local conditions is one of the important principles for the construction and operation of sewage treatment equipment. It is necessary to determine the type, size and design parameters of the equipment according to the local actual situation, and to choose the sewage treatment technology scheme in line with the local economic conditions and geographical environment. At the same time, the energy efficiency and maintainability of the equipment need to be considered to ensure the long-term and stable operation of the sewage treatment equipment and good economic and social benefits.
