A kind of comprehensive utilization method of tributoxyethyl phosphate wastewater

Abstract

The invention discloses a treatment method of tributoxyethyl phosphate wastewater, which comprises the following steps: TBEP alkaline washing wastewater undergoes saponification reaction with alkaline solution, completely reacting residual phosphate in the wastewater to generate phosphate sodium salt, To obtain saponification wastewater, add an acidic solution into the saponification wastewater and react, then let it stand for stratification, and separate the lower acidic water phase and the upper oil phase; the lower acidic water phase is neutralized and then distilled to obtain industrial salt and distilled water; the upper oil phase is dehydrated by distillation Afterwards, continue to distill to obtain the crude product of ethylene glycol monobutyl ether and the distillation bottom liquid. The crude product of ethylene glycol monobutyl ether is collected after being circulated and dehydrated in a molecular sieve packed tower; the distillation bottom liquid is neutralized and distilled and dehydrated to obtain TBEP sodium salt. The invention solves the problem of generation and treatment of hazardous solid waste in the wastewater treatment method of the prior art, and thoroughly solves the problem of fouling and clogging of sodium phosphate ester in the MVR pipeline of the high-efficiency distillation system and cannot be used normally.

Description

technical field [0001] The invention relates to a comprehensive utilization method of tributoxyethyl phosphate wastewater. Background technique [0002] Tributoxyethyl phosphate flame retardant, English name Tris (2-butoxyethyl) pHospHate, referred to as TBEP, also known as ethylene glycol monobutyl ether phosphate triester, the molecular formula is C 18 h 39 o 7 P, molecular weight 398. It is a kind of flame retardant plasticizer, which is mainly used for flame retardant and plasticizing of polyurethane rubber, cellulose, polyvinyl alcohol, etc., and has good low temperature characteristics. The product has a wide range of uses, the market demand continues to increase, and has the characteristics of low smoke, halogen-free, non-toxic, etc., which is in line with the development direction of flame retardants, halogen-free and environmentally friendly, so it has a good development prospect. In the production process of flame retardant TBEP, about 0.5 tons of alkaline wast...

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Problems solved by technology

[0004] 1. Pre-distillation pretreatment measures such as oxidation of TBEP wastewater, flocculation and precipitation to remove phosphorus cannot remove phosphorus in the water, and phosphorus is still dissolved in the wastewater in the form of TBEP sodium salt. On the contrary, the pretreatment caused by the addition of flocculants and other agents Increase in Hazardous Solid Waste

[0005] 2. When TBEP wastewater is continuously distilled and dehydrated to separate chlorine and phosphorus elements in the water, the TBEP sodium salt in the wastewater will precipitate as the water decreases, and its shape is similar to high-viscosity sludge, which cannot be centrifugally separated by the general crystalline sodium chloride method. Cause scaling on the inner wall of the equipment, blockage of the material transfer and return pipeline, resulting in extremely poor steam heating effect, low distillation efficiency, high equipment failure shutdown rate, etc.

[0006] 3. The content of sodium chloride in TBEP wastewater is extremely low, and when TBEP wastewater is pretreated by the environmental protection station and combined with other phosphate wastewater for MVR dehydration, the industrial salt separated by salt will make the appearance of the large amount of TBEP sodium salt and sodium chloride content does not meet the industrial salt quality standards

[0007] 4. The recyclable ethylene glycol monobutyl ether in wastewater has no effective recovery process, resulting in waste

The mass content of ethylene glycol monobutyl ether phosphate diester sodium salt in TBEP production wastewater is more than 75%. Since the company's original process did not separate inorganic salts and organic salts, the final wastewater obtained by distillation and dehydration Phosphate sodium salt solid contains nearly 1 / 3 of the mass of sodium chloride, and its active ingredient ethylene glycol monobutyl ether phosphate diester sodium salt has a mass content of less than 50%. sale, but can only be treated as hazardous solid waste

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