The following factors generally need to be considered in the selection of processing process.

1 Wastewater water qualityDomestic sewage water quality is usually relatively stable, and general treatment methods include acidification, aerobic biological treatment, disinfection, etc. The industrial wastewater should be reasonably selected according to the specific water quality situation. In particular, it should be pointed out that for the use of aerobic biological treatment process to treat wastewater, it is necessary to pay attention to the biodegradability of wastewater, which usually requires BOD5/COD>0.3, if the requirements cannot be met, anaerobic biological hydrolysis acidification can be considered to improve the biodegradability of wastewater, or the physical or chemical methods of non-biological treatment can be considered.

2. Degree of sewage treatment

This is the main basis for selecting the sewage treatment process flow. The degree of sewage treatment generally depends on the water quality characteristics of the sewage, the direction of the treated water, and the self purification capacity of the water body into which the sewage flows. However, currently, the determination of the degree of sewage treatment mainly depends on the requirements of the relevant legal system and technical policies of the country. Usually, environmental management departments control the concentration of wastewater discharge based on the Comprehensive Wastewater Discharge Standards and related industry discharge standards. Some regions with higher levels of economic development also have stricter local discharge standards. Therefore, regardless of the type of wastewater that needs to be treated, and regardless of the treatment process and degree adopted, it should be based on the premise that the effluent of the treatment system can meet the standards. Prevent and control water environmental pollution in accordance with the requirements of laws, regulations, and policies.

3 Construction and operation costs

When considering construction and operation costs, it should be a prerequisite for treating water to meet water quality standards. Under this premise, the low cost process of engineering construction and operation should be given due attention. In addition, reducing the footprint is also an important measure to lower construction costs.

4. Difficulty level of engineering construction

The difficulty level of engineering construction is also one of the influencing factors in choosing the process flow. If the groundwater level is high and the geological conditions are poor, it is not suitable to use deep and difficult to construct treatment structures.

5 Local Natural and Social Conditions

The local terrain, climate, and other natural conditions also have a certain impact on the selection of wastewater treatment processes. If the local climate is cold, appropriate technical measures should be taken to ensure that the process can operate normally during low temperature seasons and achieve standard water quality.

Local social conditions such as raw materials, water resources, and electricity supply are also factors that should be considered in process selection.

6. Water volume of sewage

In addition to water quality, the amount of sewage is also one of the influencing factors. Welcome to follow the eco-friendly little bees. For sewage with large changes in water quantity and quality, the first consideration should be to adopt processes with strong shock load resistance, or to consider setting up buffering equipment such as regulating tanks to minimize adverse effects.

7 Secondary pollution

During the sewage treatment process, attention should be paid to whether it will cause secondary pollution problems. For example, pharmaceutical factory wastewater contains a large amount of organic substances (such as benzene, toluene, bromine, etc.), and there will be organic waste gas emissions during the aeration process, which will have an impact on the surrounding atmospheric environment; The wastewater from gas production in fertilizer plants is recycled after sedimentation and cooling treatment. Cyanide is present in the tail gas of the cooling tower, causing pollution to the atmosphere; In the treatment of LeGuo wastewater in pesticide factories, the use of alkalization method to degrade LeGuo, such as using lime as alkalizing agent, will result in secondary pollution of the generated sludge; When treating wastewater from printing and dyeing or dye factories, the disposal of sludge is a key consideration.

In short, the selection of sewage treatment processes should comprehensively consider various factors and conduct technical and economic comparisons of multiple schemes in order to draw conclusions.