There are many successful examples of wastewater treatment in printing and dyeing plants, but there are also many poor results, and the reasons are roughly as follows:

1.The printing and dyeing factory has not analyzed its own wastewater characteristics (water quality, water quantity), copying the experience of other factories, the results are often not ideal.

2.The design specifications of urban sewage treatment for printing and dyeing wastewater treatment, only change some parameters, resulting in great losses. Especially in the early days, the centralized treatment of wastewater from large printing and dyeing plants was responsible for large design institutes, which did not have a deep understanding of the nature of printing and dyeing wastewater, causing great losses.

3.New technologies, new processes, new agents have not been pilot-tested, directly used in engineering, resulting in many failures. New technologies should go through small trials, pilot trials, in order to be used in engineering, the general pilot scale is 3%-5% of the engineering water, that is, up to about 20 times larger. The results of laboratory research are directly applied to engineering, and there are few successful cases. The most mature and reliable technology should be used in the project.

4. Similar treatment processes can be used for wastewater with similar production processes, but technical parameters should also be appropriately adjusted according to water quality and water quantity to ensure the treatment level.

5.The actual operation technology and management technology is improper, not properly adjusted according to the change of wastewater, but also the cause of unstable operation.