Process for treating disperse dye production wastewater and recycling salt resources

Abstract

The invention discloses a process for treating disperse dye production wastewater and recycling salt resources. The process comprises the following specific steps: Q1, neutralization treatment: generating sodium sulfate; Q2: ECO subcritical water catalytic oxidation: degrading macromolecular organic matters into micromolecular organic matters, acidic substances, CO2 and water under the action of a catalyst; Q3, gas-liquid separation: carrying out coarse filtration by a gas-liquid separator to obtain residual oxidation liquid; Q4, freezing crystallization: freezing the oxidized liquid to obtain sodium sulfate decahydrate; Q5, concentration and separation via nanofiltration membrane: circularly concentrating the oxidized liquid until the total recovery rate of sodium sulfate decahydrate is 90-99.9%; and Q6, biochemical treatment: recovering sodium formate salt or formic acid, and carrying out treatment until an emission standard is reached. According to the whole process, salts and organic solvents in the disperse dye production wastewater can be recycled, maximum recycling is achieved, the purpose of zero wastewater discharge is achieved, a treatment route of the process can be shortened, operation cost and actual operation difficulty can be reduced, and prominent substantive features and remarkable progress are achieved.

Description

technical field [0001] The invention relates to the technical field of industrial wastewater treatment, in particular to a process for treating wastewater produced by disperse dyes and recovering salinity resources. Background technique [0002] With the rapid development of the dye industry, my country has become the largest dye producer in the world. The "three wastes" produced in dye manufacturing, especially wastewater, are the main source of my country's dye industry becoming a major polluter. [0003] Due to the increasing demand for disperse dyes at home and abroad, environmental problems have become increasingly prominent. Disperse dyes are a kind of important organic dyes with relatively small molecules and no water-soluble groups in structure. They are mainly used for dyeing polyester fibers (polyester) and their blended fabrics. They have the characteristics of bright color and washability. Since disperse dyes are insoluble in water, a large amount of sulfuric ac...

AI Technical Summary

Problems solved by technology

[0008] The present invention provides a new process for the treatment of disperse dye production wastewater and salinity resource recovery in view of the defects in the prior art, such as long process treatment route, high operating cost, and difficult actual operation of acid-containing disperse dye wastewater.

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