Abstract:

Aining at the difficult treatment of acidic wastewater of disperse dyes and easy production of secondary pollution, taking the acidic mother liquor wastewater grnerated in the prodrction of Disperse Blue 291：3 filter cake as an example, the comprehensive recycling and resource utilization technology were strdied. The paper also explores the energy conservation and emissions reduction process of dye wastewater. Disperse Blue 291：3 acidic mother liquor wastewater was treated by neutralization, decolorization and separation fine filtration, concentration and crystallization by mechanical vapor recompression (MVR), centrifugal separation. The residual dyes and other organic matter in acidic disperse dye wastewater are removed. Then ammonium sulfate with the nitrogen content of more than 20.92% and the free acid (sulfuric acid) content of less than 0.1% was prepared. In this way，the recycling and reuse of the acidic disperse dye wastewater are achieved. All the processes realize the automatic and continuous, green, clean and efficient production. Meanwhile, the application of the evaporation and concentration technology of MVR taking advantage of recycling of its secondary steam energy, improves the economic and environmental benefits of the preparation of ammonium sulfate.

Key words: ammonium sulfate, acidic wastewater, disperse dye, automatic and continuous production