Abstract:

A large amount of wastewater in the production process of 1,2,3,9-tetrahydrocarbazol-4-one is generated and leads to severe harm. In this work, the effects and existing problems in oxidation treatment were investigated. Meanwhile, the new process route of high-temperature carbonization treatment was developed. The results show that the oxidation treatments with NaClO and H₂O₂ fail to achieve the desired effect, and the recycled solid is poor in color and has no catalytic activity. However, zinc chloride recovered through distilling at 143 ℃ and high-temperature carbonization at 500 ℃ for 40 min, exhibits excellent catalytic activity, which makes the conversion of monophenylhydrazone reach 52.6%. Ultimately, the reclamation of zinc chloride in the production of 1,2,3,9-tetrahydrocarbazol-4-one is realized. At the same time, the experimental results provide a new way for the treatment of 1,2,3,9-tetrahydrocarbazol-4-one production wastewater and comprehensive utilization of resources.

Key words: 1,2,3,9-tetrahydro-4H-carbazol, oxidation treatment, high-temperature carbonization, zinc chloride