Case analysis
Product classification: Plastic washing wastewater treatment engineering
Project Name: Jiangxi a plastic recycling wastewater treatment project
Pollution control type: plastic washing wastewater and daily sewage treatment
Processing scale: daily processing capacity of 100 tons
Implementation of standards: integrated emission standards
Treatment process: the use of drum filter washing plastic sewage treatment equipment combined method
Project brief introduction: plastic washing wastewater treatment project of plastic recycling granulation plant, the water treatment volume of the project is 100m/d, and the treatment effect reaches the national first-class discharge standard.

Characteristics and difficulties of plastic washing wastewater treatment
Plastic recycling produces a certain amount of waste water in the production process. The main source of water is the raw pollution source in the recycling process of waste plastics, which mainly comes from the cleaning and separation of waste plastics and the wet crushing process. The concentration of pollutants in wastewater is closely related to the nature of waste plastics used in its production. If it is a coarse material containing a lot of sundries, which contains a lot of paper, soil particles and other sundries, and is a variety of types of plastic, its water production is also relatively large, can reach 10 t/t plastic, the cleaning and crushing process of wastewater organic matter, suspended solids content is high, of which COD can reach 2000mg/L, and SS can reach 500mg/L. For imported primary granular materials and secondary granular materials, cleaning process may not be carried out. Even if cleaning is carried out, the amount of wastewater is about 2tt raw materials, and the contents of organic matter and suspended solids in the wastewater are relatively low. Generally, COD is 500mg/L and SS is 200mg/L. Through the biochemical experiments of wastewater, it is found that the biochemical differences of wastewater produced by different raw materials are large, but its biodegradability is generally not very good. If not treated directly discharged will cause a certain degree of impact on the surrounding environment. It is necessary to handle and dispose of the grid slag and sludge generated during the treatment process to avoid secondary pollution.

Inlet and Outlet Water Quality Analysis

Water quality characteristics of plastic washing wastewater
1) The content of organic pollutants such as organic ammonia, CODcr, BOD5 in wastewater is high, which is some of the residual substances on the surface of waste plastics. The composition of pollutants in sewage is more complex and it is difficult to deal.
2) Good biodegradability: the B:C ratio of pollutants in wastewater is 0.30, and the B:C ratio of wastewater basically conforms to the biodegradation treatment conditions. Biological oxidation treatment can only be carried out after adjusting PH value, water temperature, water quality and water quantity.
3) The wastewater contains a large amount of solid impurities and suspended solids, which must be pretreated.
4) Wastewater contains a variety of compounds, and the toxicity coefficient of wastewater inhibits the growth of microorganisms.
5) The water quality and quantity of wastewater change from time to time: the wastewater treatment system is required to have a high ability to adjust and adapt to the water quantity and water quality.

 
Effect after treatment
The water quality of the sewage treatment system designed for the plastic washing plant is good, and the main water quality indicators can meet the discharge standards, which can well adapt to the unstable water quality. The effluent of the system can reach the first level standard of comprehensive sewage discharge, which effectively solves the reality that some indicators in this kind of wastewater exceed the standard. According to the actual requirements and design process, the use of drum filter washing plastic sewage treatment equipment combination method, in order to improve water quality, meet the requirements of effluent standards and ensure the long-term stable operation of the set of sewage treatment system.