Check Pollution Control Method Of Chemical Fiber Factory Under National Environmental Protection Policy

The pollution control of chemical fiber factory is becoming more and more urgent. Therefore, how to effectively solve the pollution problem of chemical fiber enterprises has become a major event for the chemical fiber factory.

Chemical fiber production plants produce various kinds of wastewater in the process of chemical fiber production, such as PET wastewater, PTA wastewater, cotton pulp black liquor, viscose wastewater and so on. The composition of its wastewater is complex. It often contains strong acid, strong alkali, cellulose, hemicellulose, alcohol, pectin, and all kinds of toxic substances. For example, the main pollutants in PET wastewater are ethylene two ester, ethylene glycol, terephthalic acid and its intermediates and oligomers. PTA waste water contains mainly benzene, two formic acid, p-xylene, benzoic acid, methyl acetate, acetic acid and other pollutants; polyester wastewater contains pollutants such as PTA, acetaldehyde, EG, two glycols, three glycol, spinning oil and other pollutants.

The content of organic matter in chemical fiber wastewater is high, COD is between 1000 and 10000mg/L, sometimes higher. The biodegradability of wastewater is poor, and BOD/COD is generally less than 0.25. Waste water is acidic or alkaline, and contains toxic substances such as aldehydes, cyanides and benzene, which are toxic to microorganisms.

In order to improve the environment and respond to national policies, chemical fiber enterprises adopt various methods to treat chemical fiber wastewater.

　　 Case 1: a certain Henan chemical fiber Factory wastewater treatment

The wastewater treatment process of the plant is mainly based on the "card ruse" oxidation ditch. After operation, the effluent COD and BOD5 reach the two level of national sewage discharge standard.

The operation results show that the process is feasible and effective in treating chemical wastewater. efficiency High sludge and less sludge have strong adaptability to the changes of water temperature, water quality and water quantity. The process has the function of removing sulfur and zinc to eliminate bubbles, and considers that the pH value of the acid station is adjusted to reduce the amount of acid and reduce the cost, so as to achieve the goal of waste disposal.

Case two: wastewater treatment of a chemical fiber company in Shijiazhuang

The lactam engineering is the first production of caprolactam from toluene in China. Technology The process is characterized by many kinds of raw materials and intermediate products, complex engineering processes and many by-products. The quantity and quality of production wastewater vary greatly and belong to high concentration nitrogen containing organic wastewater.

Operation effect: during the stable operation of the project, the control parameters of the ENSBR main reactor are DO4 to 4mg/L, the sludge concentration is 8 to 10mg/L, and the average water temperature is 30 centigrade. As the ENSBR process formed a concentration gradient and facultative aerobic alternation on the reaction time, the degradation of COD not only avoided the consequences of malignant expansion of filamentous bacteria due to the growth of microorganisms, but also maximally removed nitrogen oxides in water. The effluent control indexes can meet the design requirements and meet the emission standards.

Case three: wastewater treatment of Sinopec Yizheng Chemical Fiber Co., Ltd.

The 450 thousand t/a PTA project of Sinopec Yizheng chemical fiber company adopts the "anaerobic AF+A/O" process, making Yizheng chemical fiber the first domestic enterprise to use AF for PTA wastewater treatment. The anaerobic reactor (AF) process adopts the German Envirosia technology, and the final effluent runs the first level standard of the comprehensive discharge standard for sewage (GB8978-1996). The system has good effect since the operation of the 2006.