Analysis and Countermeasures of township sewage tr

2022-08-17
  • Detail

Thinking: township sewage treatment technology decision-making analysis and Countermeasures

Abstract: by analyzing the characteristics and treatment status of rural sewage in China, this paper points out the problems existing in rural sewage treatment in China at present, and then analyzes the characteristics of rural sewage collection, sewage construction scale and design water quality, and makes technical decisions on the process selection principles, process optimization decisions and process selection of rural sewage treatment, The Countermeasures of rural sewage treatment in China are put forward

key words: Township; Sewage treatment; Technical analysis; Countermeasures

Introduction

in recent years, the state has made great efforts to control water pollution. The continuous increase of sewage discharge in villages and towns in China has also become an important control object. With the launch of the national water resources protection planning project, a number of township sewage treatment projects have been built in the "three rivers and three lakes", the Bohai Sea and the Three Gorges Reservoir area. However, the construction of township sewage treatment projects in China is still in its infancy, and there is no special design specification and standard. For example, copying the technology and process used for urban sewage treatment, after the completion of the project, there will be high technical requirements, complex operation and difficult operation. Even in the sun, it will not be compatible with the level of township economic development, personnel quality and technical level, and it will not be able to give full play to its due benefits. Therefore, it is necessary to consider the particularity of township sewage treatment, analyze the characteristics and existing problems of township sewage treatment, and make scientific and reasonable technical decision-making analysis on township sewage treatment technology, so as to realize the sustainable development of township

1. The current situation of township sewage treatment in China

1.1 the amount of sewage is small and scattered, which is difficult to collect, and the lack of drainage facilities

due to the lack of scientific planning, unreasonable layout, imperfect or no drainage facilities, complex terrain, scattered residents, narrow roads, imperfect infrastructure and other factors, it is difficult to collect township sewage

1.2 the water quality and quantity change greatly

the water quality is very unstable; The water volume changes day and night. The drainage volume in the morning and night is smaller than that in the day and night, and may even stop. The sewage discharge is in a discontinuous state, and the water consumption change coefficient is much larger than the value in the city

2. Problems in township sewage treatment

2.1 insufficient drainage system

most townships in China have no systematic planning, imperfect water supply facilities, and imperfect sewage collection pipes. Rainwater and sewage are discharged into the water body along the roadside ditches or nearby roads in an unorganized state, causing difficulties in sewage collection. Due to the narrow streets, dense buildings on both sides, complex construction and restricted by local economic conditions, some towns and townships have unconditionally built drainage systems

2.2 lack of construction standards

at present, there are no drainage design standards, specifications and procedures for township sewage treatment projects in China. At present, the current relevant standards and specifications are still used in the design and construction of urban sewage treatment projects, resulting in high construction and operation costs of township sewage treatment projects. In addition, the design and construction of township sewage treatment projects are fully applicable to the current design standards and specifications, which is obviously not applicable

2.3 lack of appropriate treatment procedures

the use and advantages of steel bar bending testing machine in general villages, the economic foundation of the town is weak, and the construction funds of sewage treatment projects are scarce. There is a lack of practical treatment process suitable for the characteristics of township sewage, most of which are the promotion or copying of sewage treatment process and design parameters in large and medium-sized cities, resulting in high project investment and operation costs

3. Technical decision-making analysis of township sewage treatment projects

3.1 analysis of the characteristics of township sewage treatment projects

3.1.1 sewage collection

township sewage collection should select the appropriate drainage system according to the local specific situation, after comprehensive weighing and detailed cost-benefit analysis. Generally speaking, the catchment area of villages and towns in China is small, the total amount of pollutants is small, and the economic strength is generally weak. There are almost no pipes that meet the drainage requirements, and most open ditches and culverts are used for rainwater and sewage combined drainage. Therefore, interception facilities can be set at the end of the water drainage system formed by the culvert section of the open channel. During the dry season, the sewage can be directly transported to the sewage treatment plant for treatment. During the rainy season, sewage and some rainwater are intercepted and sent to the sewage treatment plant for treatment, and the rest is discharged into rivers, reservoirs or nearby low-lying areas. For new or expanded villages and towns, a diversion drainage system should be adopted

3.1.2 treatment to identify the wear resistance objectives and requirements of the ink layer (or coating)

according to different types of receiving water and water quality, township sewage discharge should implement different discharge standards

for sewage treatment plants that discharge into closed and semi closed waters and have eutrophication or eutrophication threatening waters, the sewage with phosphorus and nitrogen removal function should be selected for secondary treatment process. For sewage treatment plants discharged into open water bodies, water quality targets can be implemented in stages based on environmental impact assessment according to the local economic development level and water environment conditions, so as to gradually meet the standards. Township sewage treatment involves a wide range and the situation is relatively complex. In addition, the geographical location, economic and environmental conditions, sewage discharge status and treatment planning of the township are different, so the specific treatment objectives need to be analyzed and treated differently

3.2 township sewage treatment process selection

3.2.1 process selection principles

in order to improve the quality of township water environment and achieve sustainable economic and social development, the construction of township sewage treatment facilities should be based on the requirements of township overall planning, water environment planning, comprehensive utilization planning of water resources and township drainage special planning, guided by the scientific concept of development, and the general principle of "economic applicability and economic applicability", Reasonably determine the layout and construction scale of sewage treatment facilities, and adopt township sewage treatment technology and process according to local conditions. It includes the following steps: 1) the process technology is mature, reliable and feasible; 2) Meet the requirements of processing function and efficiency; 3) Small construction investment and low operation cost; 4) Considering regional differences, scale and process supporting needs, adjust measures to local conditions; 5) The actual operation is simple, easy to maintain and manage, easy to transform and expand, and implemented in stages. 6) The new technologies and processes adopted should be used gradually, steadily and appropriately. For the township sewage treatment of township enterprises and industrial parks, we need to treat them differently, accurately analyze the water quality and quantity, and then take the corresponding technical route

3.2.2 process selection optimization

use analytic hierarchy process to optimize township sewage treatment process. The sewage treatment technology suitable for villages and towns is divided into three levels, the highest level is the overall target level, that is, the sewage treatment technology suitable for villages and towns; The second layer is composed of four index layers: sewage treatment effect, technical economy, operation management, social benefit and environmental benefit, so as to achieve the overall goal; The lowest level is the condition to achieve the overall goal and secondary goals. The removal rates of BOD, COD, SS, NH3-N and TP are taken as the evaluation indexes of wastewater treatment effect. Select infrastructure cost, operation cost, land occupation index, energy consumption and process complexity as technical and economic evaluation indicators; Select operation reliability and operation difficulty as the evaluation indicators of operation management; Energy conservation and emission reduction, COD emission reduction and BOD emission reduction are selected as the evaluation indicators of social and environmental benefits. In order to establish the evaluation index system of township sewage treatment process optimization, various comprehensive indexes suitable for township sewage treatment process are calculated by using linear weighted sum function, and the township sewage treatment process optimization scheme is determined according to the comprehensive indexes

3.2.3 process selection steps

1) clarify the characteristics of township positioning. Including the nature, geographical location, water pollution control, total pollutant control requirements of the township. 2) analyze and evaluate the socio-economic development and infrastructure of the township. 3) According to the location of the township, the local economic development level, the conclusion of environmental impact assessment and other factors, reasonably determine the township sewage treatment level and discharge standards. 4) According to the quality characteristics, quantity and discharge requirements of township sewage, carefully analyze the performance, investment cost, operating conditions and adaptability of township sewage treatment process. 5) Effectively screen township sewage treatment technologies, mainly analyze the performance, construction and operation cost of the treatment technology, application scope and conditions, and recommend supporting treatment technologies according to different types of towns

4. Township sewage treatment countermeasures

(1) improve the relevant laws, regulations, standards, norms and regulations of township sewage treatment. (2) Strengthen government guidance and support. The government should attach great importance to the energy conservation and emission reduction work of township sewage treatment, and increase the investment and financing of township sewage treatment projects. (3) Establish and improve the drainage system. According to the current situation, trend and overall planning requirements of township economic development, gradually establish and improve the township drainage system, focusing on the construction of rainwater and sewage pipes. (4) Take measures according to local conditions and treat them differently. When selecting the township sewage treatment process, the process flow demonstration should be carried out according to the local overall planning, economic conditions, technical level, landform and other conditions, and the best process route should be determined through the analysis and comparison of economic, technical, management and other comprehensive factors. (5) Fully investigate and master the data. Comprehensively investigated the characteristics of township sewage in different regions, accurately analyzed the quantity and quality of township sewage, and selected a reasonable treatment process. (6) Sewage reuse and rational utilization. Combined with the characteristics of villages and towns, in order to alleviate the global water crisis, the treatment of recycled water can be properly considered. For example, for irrigation, it breaks the foreign monopoly or fish farming in the high-end manufacturing field of power transmission and distribution, but the water quality should meet the corresponding discharge standards. (7) Scientific and technological research, pilot demonstration. Actively carry out research on township sewage treatment science and technology projects, and the research results can be used to guide township sewage treatment consulting design, pilot demonstration and promotion and application. (8) Provide on-the-job training. Due to the constraints of technical force and management level of township sewage treatment, the selected process should be simplified and easy to operate. If necessary, post and technical training should be carried out for management, operation and maintenance personnel. (9) Strengthen the publicity of environmental protection, improve the awareness of environmental protection of the whole people, and actively participate in the construction, implementation and operation supervision of township sewage treatment

conclusion

to sum up, sewage treatment plants should try to avoid affecting the normal life of residents. Therefore, sewage treatment must be innovative. Sewage treatment will increasingly improve the efficiency of sewage treatment, pay attention to nitrogen and phosphorus removal, and organically combine with advanced science and technology and environmental protection projects. Among them, ecological dialysis technology and resource technology are a new sewage treatment method guided by the concept of ecological green, which is of great significance to improve the quality of sewage treatment and green sewage treatment

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