Process for zero-discharge treatment of o-phenylenediamine sodium sulfide reduction wastewater

Abstract

The invention relates to a zero-emission treatment process of O-phenylenediamine sodium sulfide reduction wastewater, which adopts the following steps in sequence: wastewater is filtered; O-phenylenediamine in the wastewater is absorbed and extracted by resin; the remained wastewater is vaporized and extracted to remove sodium chlorine; the wastewater that sodium chlorine is removed is filtered and crystallized to extract the sodium thiosulfate; the remained wastewater is concentrated to obtain sodium sulfite mixture. The invention can treat O-phenylenediamine sodium sulfide reduction wastewater with zero emission, so as to solve environmental pollution of wastewater thoroughly, thereby having obvious environmental benefit; simultaneously the wastewater is treated by the means of resource utilization, organic chemical product- O-phenylenediamine and inorganic product- sodium thiosulfate and sodium thiosulfate mixture are extracted from the wastewater; full process is a cleaning treatment process, not only secondary pollution is not generated but also energy is utilized circularly during process; the invention has small investment, simple process and practicality, and is applicable for popularization and utilization in the industry.

Description

technical field [0001] The invention relates to the purification and treatment technology of chemical wastewater, in particular to a zero-discharge process for treating ortho-phenylenediamine sulfide alkali reduction wastewater. Background technique [0002] O-phenylenediamine, a popular chemical product in domestic and foreign markets, is mostly obtained by the reduction method of alkali sulfide. In the production process of o-phenylenediamine, a certain amount of high-concentration and toxic chemical wastewater will inevitably be produced. If it is discharged directly without purification treatment, it will cause serious environmental pollution. At present, some manufacturers use o-phenylenediamine sulfide reduction wastewater as mother liquor to regenerate sodium thiosulfate to recover useful components in wastewater and reduce pollution. But this treatment method needs to add sulfur to carry out oxidation reaction in the process of producing sodium thiosulfate product, ...

AI Technical Summary

Problems solved by technology

Although the above-mentioned patent application project has proved in practice that it has indeed produced a lot of beneficial effects, there are still some imperfections in this method, such as: (1) there is also o-phenylenediamine with a content of about 1% in the reduction wastewater Without separate treatment, these o-phenylenediamines are finally retained in the sodium sulfite mixture as impurities, and there is potential pollution to the environment;

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