Project profile ：
Xidan Village, Zhutai Town, Linzi District, Zibo City, located in the middle of Shandong Province, is a typical plain village with flat topography. The central village covers an area of 0.2 square kilometers, with a resident population of about 330 households and 1220 residents, and a high degree of residential agglomeration. The village cultivated land area of 1512 mu, vegetable greenhouses 160 mu, lotus pond 50 mu, the economic foundation is good, water, natural gas, roads, greening and other infrastructure perfect, was included in the rural revitalization "ten hundred thousand" demonstration project. The village has achieved full coverage of toilets, and domestic sewage sources include toilets, washing vegetables, washing and bathing, with a production capacity of about 40m³/d. The discharge of rural domestic sewage fluctuates greatly, and the operation cost of conventional treatment mode and process is generally high.
In 2020, Shandong Wenyuan Environmental Protection Company upgraded the Xidan Village sewage station. Using high-load infiltration composite technology, the treatment scale is 50m³/d, and the effluent reaches the level A standard of Pollutant Discharge Standards for Urban Sewage Treatment Plants. At the same time, through mobile phones and the Internet to achieve remote monitoring, debugging, maintenance of sewage treatment equipment, no need for special duty.
As a result of global warming, higher temperatures can melt polar glaciers, and sea levels will rise by 6 cm every 10 years, thus flooding some coastal areas. These can lead to changes and destruction of ecosystems.
Project demonstration significance ：
With the continuous improvement of rural construction and the improvement of people's living standards, the discharge of rural domestic sewage has been increasing year by year, and the composition of sewage has become increasingly complex. Untreated rural domestic sewage is not only a potential threat to drinking water sources, but also an important reason for the eutrophication of rivers and lakes. Promoting the treatment of rural domestic sewage is an important part of implementing the improvement of rural living environment, fighting the battle of pollution control in agriculture and rural areas, making up for the shortcomings of rural living environment, accelerating the construction of a beautiful and livable countryside, and promoting the revitalization of rural ecology.
Rural domestic sewage is different from urban sewage and has its own characteristics :
(1) Small scale, except for small towns, the rural population is scattered, the water volume is relatively small, and the corresponding amount of domestic sewage is also small;
(2) The composition is complex, due to rainwater and groundwater infiltration, resulting in a low concentration of pollutants, and great volatility, it is difficult to assess its pollution load;
(3) The discharge of rural domestic sewage is larger in the high water period than in the low water period, and larger in the morning and evening than in the day, which affects the correct selection of rural domestic sewage treatment methods, the reasonable design of treatment technology and pollutant removal program, the accurate estimation of effluent water quality and the normal operation of sewage treatment facilities;
(4) The nature of most rural domestic sewage is not very different, the water basically does not contain heavy metals and toxic and harmful substances (but with the improvement of people's living standards, some domestic sewage may contain heavy metals and toxic and harmful substances) contains a certain amount of nitrogen and phosphorus, water quality fluctuations, strong biodegradability.
Therefore, the sewage treatment process of small towns and rural areas should be decided after a comprehensive technical and economic comparison according to the local treatment scale, water quality characteristics, environmental functions of the water body, the actual geographical environment and requirements of the local.
The main technical and economic indicators can be divided into:
1) Investment in the amount of sewage treated per unit
2) Reduce investment per unit of pollutant
3) Power consumption and cost of treating unit sewage volume
4) Reduce the power consumption and cost per unit of pollutants
5) Floor space
6) Reliability of operating performance
7) Management and maintenance difficulty
8) Overall environmental benefits
Taking the above aspects into consideration, the water treatment investment and operation costs are within the scope of the local finance and residents can afford, otherwise, it will affect the effective normal operation of water treatment facilities, and it is difficult to ensure the real improvement of the water environment.
While retaining the main advantages of conventional subsurface percolation technology, the high-load subsurface percolation composite technology greatly reduces the required percolation area and construction investment, and has been authorized by 7 Chinese invention patents. Because of its outstanding economic and environmental benefits, it has become the preferred technology for decentralized point source domestic sewage treatment in Europe and the United States, and has repeatedly won the praise of the competent authorities and owners, reflecting its technical advantages of "affordable, affordable, good effect and sustainable" in the sewage treatment of villages and towns.
Project highlights ：
(1) Implementation effect
After the treatment of domestic sewage in the village, the effluent water quality has reached the "Pollutant Discharge Standard of Urban sewage Treatment Plant" Level A standard.
The main body of the construction of Xidan sewage treatment station is the village committee, which entrusts a professional third-party operation and maintenance company to carry out operation and maintenance management and technical services. The whole processing system is only equipped with one lift pump and one air exchanger, which are intermittent and short-time operation, and the equipment failure rate is low. And relying on the intelligent Internet of Things platform, to achieve real-time monitoring of sewage equipment, equipped with online water quality testing equipment and cloud platform cameras, anytime and anywhere to understand and adjust the operating status of the equipment, equipment maintenance and management is more simple, no need to be on duty.
(2) Social benefits
Xidan Village sewage station adopts underground structure, low noise, no odor, the ground is built into a leisure theme park, regularly mobilize the masses to carry out water environment management self-inspection activities, and carry out theme propaganda around the construction of beautiful Xidan. Through the concrete implementation of this project, people realize the importance of environmental protection. In addition, with the improvement of people's quality of life, people's environmental awareness will be enhanced, and protecting the environment and saving resources will become the conscious behavior of villagers.
(3) Ecological benefits
Xidan Village sewage treatment demonstration project, the system is running normally, and the effluent is up to standard. The designed daily processing capacity is 50m³, the actual average daily processing capacity is 40m³, the annual processing capacity is 14600m³, and the annual degradation of COD4200kg, ammonia nitrogen 591kg, and total nitrogen 677.5kg are expected. It has greatly reduced the impact of the local water environment, improved the surrounding natural environment, and raised the environmental awareness of the surrounding residents.
Brief introduction of project technology/equipment：
（Brief introduction of project technology/equipment）
(1) Technical process/equipment name
High load infiltration composite technology
(2) Technical process/equipment principle
After precipitation and anaerobic pretreatment, the sewage enters the water regulation tank, and then is distributed to the high-load underground percolation unit through the lifting pump, so that the sewage is transversely transferred and vertically percolated in the artificial filter media, where the pollutants are intercepted and adsorbed by the filter media of different functional and structural layers, and finally decomposed and transformed by microorganisms.
The high-load underground percolation unit is composed of different functional and structural layers, and various functional and structural layers are rationally arranged. Each functional and structural layer has a specific formula, supplemented by a reasonable and optimized operation mode to control the migration of pollutants and the zoning of microbial communities. Moreover, the effluent quality is improved by adding efficient microbial microbial agents with specific functions. In addition, the technology makes the pollutant load automatically adjust and distribute among different subsystems, and realizes the automatic feedback adjustment of the system, so as to ensure the long-term stable operation of the system.
(3) Technical process/equipment characteristics
1) Less land and no special land required:
The percolation area required to treat 1 ton of water per day is only 0.8 square meters, and the surface can be planned as a park, green space, and leisure square;
2) The running power consumption is very low:
The power consumption of conventional biochemical process is generally 1.2 degrees of electricity /m³ sewage, and the power consumption of this process is about 0.2 degrees of electricity /m³ sewage.
3) Easy maintenance:
The whole system is only equipped with one lifting pump and one air exchange fan, and both of them are intermittent and short-time operation, the equipment failure rate is low, and basically no manual maintenance is required.
4) Good processing effect, stable operation:
The main indicators of the effluent can meet the "Pollutant Discharge Standard of Urban Sewage Treatment Plant" Grade A standard, no odor, no organic sludge discharge, strong resistance to pollution load and hydraulic load impact, and normal and stable operation in low temperature in winter;
5) In line with national needs:
Our land resources are precious, especially in the northern areas. The traditional process basically requires the use of special land, after the completion of the process on the ground can be planted or greening, the nature of the land does not change, can effectively use the land;
6) Application field:
Applicable processing scale from 3-5 households/day to 10,000 tons/day, can be flexibly designed according to the actual situation;
Factory/project site/process equipment
Water inlet / outlet and greening
Before / after construction