Separation reagent for emulsified oily wastewater, preparation method and separation method

Abstract

The invention discloses a separation reagent for emulsified oily wastewater, a preparation method and a separation method. The separation reagent is a bicarbonate solution containing a switch solvent.The bicarbonate solution containing the switch solvent is prepared by reacting the switch solvent, carbon dioxide and water. The preparation method comprises the following steps: S1, mixing a switchsolvent with water to obtain liquid with an oil-water interface; and S2, introducing carbon dioxide into the liquid with the oil-water interface until the pH value of the liquid is stable to obtain abicarbonate solution containing a switch solvent. The separation method comprises the following steps: A, uniformly mixing emulsified oil-containing wastewater and the separation reagent, and introducing nitrogen to obtain a clear aqueous solution phase and a mixed oil phase; and B, mixing the mixed oil phase with water, introducing carbon dioxide until the volume of the oil phase is stable to obtain a switch solution, and purifying the switch solution to obtain the separation reagent. According to the invention, separation of oil and water in emulsified oily wastewater is realized, and the separation agent can be recycled to realize sustainable separation of emulsified oily wastewater.

Description

technical field [0001] The invention belongs to the technical field of emulsified oily wastewater separation, and in particular relates to a separation agent for emulsified oily wastewater, a preparation method and a separation method. Background technique [0002] Oily wastewater is one of the largest sources of pollution in industrial production and human life, and the treatment of oily wastewater has always been one of the greatest challenges facing mankind. According to the different states of oil in oily wastewater, it can be divided into suspended oil, dispersed oil and emulsified oil. Among them, emulsified oil is oil droplets with a particle size of less than 20 μm and has high stability. Therefore, the treatment of emulsified wastewater is facing greater challenges. [0003] At present, the treatment of emulsified oily wastewater is mainly divided into the following categories. (1) Solvent extraction is a traditional oil-water separation method. Since most solvent ...

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Problems solved by technology

[0003] At present, the treatment of emulsified oily wastewater is mainly divided into the following categories. (1) Solvent extraction is a traditional oil-water separation method. Since most solvent extraction agents are organic solvents, the high volatility of organic solvents restricts the development of the extraction industry. at the same time, the existence of an interfacial film between the solvent and water greatly affects the extraction efficiency

(2) Flocculation treatment of oily sewage is easy to operate, but the use of flocculants will bring secondary pollution to the environment, such as toxic sludge produced by flocculants, polymer flocculants that are difficult to be degraded by the environment, etc.

(3) Electrocoagulation technology requires large power consumption, and electrode loss is also necessary, and toxic chlorine-containing organic substances and sludge will be produced during the flocculation process

It has high permeability and separation efficiency, and is easy to operate, but the treatment of different oily wastewater has a high selectivity to the membrane, and membrane fouling is one of the main factors affecting membrane efficiency and increasing costs

Most of the above separation of emulsified wastewater is unsustainable and will cause secondary pollution or material pollution and loss

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