The Reconstruction Project Research On Printing And Dyeing Wastewater Treatment Station Of Shandong Xxx Textile Company

Textile printing and dyeing is mainly a wet technology with water as the medium,which will produce a lot of printing and dyeing wastewater in the manufacturing process.Printing and dyeing wastewater contains pollutants such as nitrogen,phosphorus,sulfide,heavy metal,surfactant and alkalinity.If not handled properly,it will not only bring safety risks to the water supply environment,but also aggravate the difficulties of water supply in China.In order to ensure the sustainable development of textile printing and dyeing industry,printing and dyeing wastewater treatment technology is constantly updated,therefore,the original printing and dyeing wastewater treatment station needs to be transformed accordingly.In this project,the optimization and reconstruction project of a printing and dyeing wastewater treatment station in Shandong xxx Textile Company is taken as an example to study the current domestic and foreign printing and dyeing wastewater treatment processes,and based on the concepts of economy,energy saving and sustainable development,aiming at the characteristics of water use and drainage quality of enterprises,through the comparison and selection of schemes,find out the wastewater treatment processes suitable for the stable operation of the printing and dyeing wastewater treatment station of the company,and analyze the benefit.This research has the characteristics of adjusting measures to local conditions and clear objectives,which provides detailed information and basis for the construction and transformation of other printing and dyeing wastewater treatment stations.Before the reconstruction of wastewater treatment station,the process of"artificial grid+hydrolytic acidification+biological contact oxidation+air flotation"was adopted.The average concentration of effluent COD_Cr,BOD₅,SS,NH₃-N and other pollution indexes were134.7mg/L,26.1mg/L,50.4mg/L and 5.5mg/L,respectively.The removal rates were 77.6%,87.6%,83.3%and 42.5%,and the average chroma of effluent was 49.2 times and 80.5%.The removal rate of all pollution indexes except NH₃-N is more than 75%after the sewage is treated in each process,but the effluent quality is still difficult to reach the class I a standard in the discharge standard of pollutants for urban sewage treatment plant（GB18918-2002）.The effluent concentration of COD_Cr,BOD₅,SS and other pollution indexes is respectively 2.7times,2.6 times and 5.0 times higher than the class I a standard.The purpose of this optimization transformation is to improve the drainage water quality.According to the requirements of this optimization transformation and the actual situation of the wastewater treatment station,a set of reasonable optimization transformation scheme is selected through scheme comparison.After the transformation,the treatment process of"mechanical grid+coagulation sedimentation+hydrolytic acidification+activated sludge+secondary sedimentation+air flotation"is adopted.Two new primary sedimentation tanks are designed to remove large particle suspended solids,reduce the load of subsequent treatment process operation,reduce the hydraulic retention time,and improve the quality of treated effluent water;The first three groups of the original biological contact oxidation tank are transformed into the activated sludge tank,and the fourth group is transformed into the secondary sedimentation tank,which improves the removal effect of organic matter,nitrogen and phosphorus,reduces the operation load of the follow-up air flotation system,and makes the water quality more stable;and the original hydrolysis acidification tank and air flotation system are overhauled,the tank filler of the hydrolysis acidification tank is replaced,and the filler is replaced Replace with PE semi soft filler.The average concentration of COD_Cr,BOD₅,SS,NH₃-N and other pollution indexes in the treated effluent is 34.2mg/L,7.6mg/L,8.9mg/Land 1.7mg/L.The removal rates are 94.3%,95.4%,97.0%and 83.2%respectively.The average chroma values of the effluent are 17.4 times and 94.2%respectively.The effluent quality of each index meets the class I a standard of pollutant discharge standard of urban sewage treatment plant（GB18918-2002）.In the sludge treatment process,the plate and frame filter press is replaced by the stacked screw type dehydrator,which solves the problems existing in the original plate and frame filter press,such as easy blockage,high demand for daily operation and maintenance,and high operation cost.The optimization and reconstruction project of a home textile Co.,Ltd.in Shandong Province has realized the purpose of improving the discharge water quality,and has better environmental ecological benefits,which provides a reference for the selection of treatment methods of similar printing and dyeing wastewater treatment stations and the reconstruction of wastewater treatment stations.