Treatment method of high-salt and high-organic waste water evaporation concentration coupled with thermocatalytic carbon crystallization

Abstract

The invention discloses a treatment method for high-salt and high-organic waste water evaporating and concentrating coupled with thermocatalytic carbon crystallization. The high-salt and high-organic waste water is pretreated with organic acid first, and then subjected to multi-effect evaporation desalination, and separated into evaporated clear liquid and high-concentration liquid. The concentrated liquid is evaporated, and the inorganic salt crystals are separated; the evaporated clear liquid is reused or discharged after physical, chemical and biochemical treatment, and the high-concentration evaporated liquid is added to a carbonization crystallization catalyst for thermal catalytic carbon crystallization reaction. After the reaction, the formed solid The liquid mixture is subjected to solid-liquid separation to obtain a solid carbonized product and a carbonized supernatant. The invention combines concentrated salt extraction, thermal catalytic carbon crystallization of organic matter and biochemical treatment to remove inorganic salt and organic matter step by step, significantly improving the salt removal rate and COD removal rate of wastewater, and has simple process, mild conditions and low treatment cost.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and in particular relates to a treatment method for high-salt and high-organic-matter wastewater coupled with thermocatalytic carbon crystallization by evaporation and concentration. Background technique [0002] High-salt and high-organic wastewater mainly comes from petrochemical, metallurgy, textile, pharmaceutical, food processing and other industries. The wastewater has high salt content, high COD, dark color, poor biodegradability, and most of them are potentially toxic (Wang Haiping. Fenton oxidation Application in the treatment of "three high" wastewater [J]. Silicon Valley, 2014, 160(16): 110-111.). With the rapid development of my country's industry, the discharge of high-salt and high-organic waste water shows a trend of increasing year by year, which brings great pressure to the ecological environment. If these high-salt, high-organic-matter wastewater is discharged ...

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Problems solved by technology

Thermal technology (evaporation), electrochemical method, membrane technology, deep oxidation method, chemical flocculation, ion exchange method and other physical and chemical methods have good treatment effects on some high-salt and high-concentration organic wastewater, but their scope of application is limited, and they cannot be recycled. The investment and disposal costs are high when the useful substances are available, which limits the scope of engineering applications of such methods

Biological method (CN 105084677A) is widely used to treat wastewater due to its economical and harmless characteristics, but the salinity in high-salt and high-organic wastewater will inhibit the microbial activity in the sewage treatment system (Ye Wenfei. High-salt organic wastewater Research progress in biological treatment [J]. Sichuan Environment, 2008, 27(3): 89-92.), and some refractory organic matter is difficult to be degraded by microorganisms, which has certain limitations

Therefore, this type of wastewater generally adopts the method of desalination and pretreatment followed by biochemical treatment (CN 101293721A). However, due to the high COD of wastewater, a large amount of mother liquor is produced in the evaporation process, and the proper treatment of these mother liquors has become a difficult problem for enterprises.

The characteristics of high salt content and high COD of this type of wastewater have brought great obstacles to its treatment. In the face of increasingly stringent sewage discharge standards, a single treatment method has certain economic and technical problems.

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