Analysis of the Sources and Characteristics of Chemical Fiber Wastewater
Chemical fiber wastewater refers to various types of wastewater generated during the production process of chemical fibers, mainly including wastewater generated during the production of polyester (PET), terephthalic acid (PTA), adhesives, etc. The composition of these wastewater is complex, containing various toxic substances and pollutants, making treatment difficult.
Source:
The sources of chemical fiber wastewater mainly include the following aspects:
Production process: In the production process of synthetic fibers, multiple stages are involved, such as esterification, condensation, spinning, etc., and each stage generates different types of wastewater. For example, esterification stripping wastewater and condensation vacuum jet water are generated in polyester production
Cleaning process: Equipment and products need to be cleaned after production, which also generates a large amount of flushing wastewater, which usually contains high concentrations of harmful substances
Raw material processing: During the transportation and storage of raw materials, leakage or loss may occur, which can also lead to the generation of wastewater
Characteristics
Chemical fiber wastewater has the following significant characteristics:
Complex composition: Chemical fiber wastewater usually contains various components such as strong acids, strong bases, organic solvents, cellulose and its derivatives. For example, the main pollutants in PET wastewater include ethylene glycol, terephthalic acid and its derivatives, while PTA wastewater contains benzoic acid, acetic acid, etc
High organic content: The chemical oxygen demand (COD) of these wastewater is generally between 1000 and 10000 mg/L, sometimes even higher, indicating a very high concentration of organic matter
Poor biodegradability: Chemical fiber wastewater usually has poor biodegradability, with a ratio of biological oxygen demand to chemical oxygen demand (BOD/COD) generally less than 0.25, which makes it difficult for traditional biological treatment methods to effectively remove pollutants from it
Strong toxicity: Due to the presence of various toxic substances such as aldehydes, cyanides, and benzenes, these components have toxic effects on microorganisms, further increasing the difficulty of treatment
Processing technology
For the treatment of chemical fiber wastewater, a comprehensive treatment process mainly based on biological methods is generally adopted, which includes the following steps:
PH adjustment: Due to the acidic or alkaline nature of chemical fiber wastewater, it needs to be neutralized first to achieve a neutral pH value.
Pre treatment: Remove suspended solids (SS) and oil substances, usually using methods such as air flotation, coagulation and sedimentation to improve the feasibility of subsequent biological treatment.
Biological treatment: Removing most organic pollutants through technologies such as activated sludge process or membrane bioreactor.
Deep processing: such as activated carbon adsorption, sand filtration, etc., to meet higher emission standards or reuse requirements
In summary, chemical fiber wastewater not only has a wide range of sources and complex components, but also poses a serious threat to the environment. Therefore, effective treatment measures need to be taken to reduce its impact on ecosystems and human health.