Environment-friendly low-energy tar refined phenol-containing sodium sulfate wastewater treatment method

Abstract

The invention discloses an environment-friendly low-energy tar refined phenol-containing sodium sulfate wastewater treatment method, wherein the tar refined phenol-containing sodium sulphate wastewater is pretreated to remove oil, suspended matters and colloid, frozen to separate out sodium sulfafe decahydrate crystals in a frozen crystallizer, then centrifuged, re-dissolved, evaporated, dehydrated and dried to obtain high-purity anhydrous sodium sulfate, and the waste heat of evaporation, dehydration and drying and part of distilled water enter the concentrated nitrification tank to dissolvethe nitrates, and fully recover the resources; the upper layer phenol-containing solution separated after freezing is subjected to extraction, dephenolization, electrode oxidation and biochemical treatment, and clear solution separated by the nanofiltration membrane and a part of the distilled water produced by evaporation, dehydration and drying are sent to a biochemical treatment device for reuse. The whole treatment process of the technology has low energy consumption, zero emission and no secondary pollution.

Description

Technical field

[0001] The invention relates to the field of environmentally friendly wastewater treatment, in particular to a method and process for treating phenol-containing wastewater from tar refining. Background technique

[0002] The sodium sulfate wastewater generated during the tar refining process is a high-salt phenol-containing process wastewater produced in the crude phenol extraction process. The process wastewater has a complex composition, not only containing highly toxic cyanide and phenolic mixtures, but also difficult to biodegrade The macrocyclic and heterocyclic substances, and there is a certain amount of tar substances in the wastewater.

[0003] The conventional treatment methods mainly include biological oxidation, adsorption and solvent extraction. Biological oxidation method treats phenol-containing wastewater, the content of phenol should be less than 300ppm, too high phenol concentration will directly inhibit and kill microorganisms, at the same time, ...

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