Method for recovering sodium chloride and glycerin from glycerin-containing high-salinity organic wastewater

Abstract

The invention discloses a method for recovering sodium chloride and glycerin in glycerin-containing high-salinity organic wastewater, which relates to the treatment of organic wastewater. The method comprises the following steps that: 1) the organic wastewater passes through macroporous resin, so that glycerin molecules in the wastewater are adsorbed, and macroporous resin with the glycerin molecules and sodium chloride-containing effluent are obtained; 2) the sodium chloride-containing effluent obtained in the step 1) is evaporated and concentrated in an evaporator, thus obtaining a sodium chloride concentrated solution; 3) the sodium chloride concentrated solution obtained in the step 2) is crystallized, thus obtaining solid sodium chloride and mother liquor left after crystallization and filtration; 4) after being diluted and biochemically treated, the mother liquor is discharged; 5) the macroporous resin treated in the step 1) is washed by using a desorption agent so as to elute the glycerin adsorbed on the macroporous resin to obtain glycerin-containing eluant and the macroporous resin subjected to eluting is put into the step 1) for cyclical utilization; 6) the glycerin-containing eluant obtained after desorption in the step 5) is distilled so as to obtain the desorption agent and crude glycerin, and the desorption agent is put into the step 5) for cyclical utilization; and 7) the crude glycerin obtained in the step 6) is fractionated, thus obtain a finished glycerin product and distillation residue liquid.

Description

technical field [0001] The invention relates to organic wastewater treatment, in particular to a recovery method for sodium chloride and glycerin in high-salt glycerol-containing organic wastewater. Background technique [0002] With the development of industry, the discharge of organic wastewater is increasing day by day. It is of great significance to treat organic wastewater so that it can be discharged up to the standard or recycled. In industrial production such as soap making industry, epichlorohydrin production, biodiesel production, and glycerin production, a large amount of organic wastewater with high salt content and a certain concentration of glycerin will be produced. The concentration of sodium chloride is about 5% to 25%, and glycerin Content about 3% ~ 15%, COD Cr About 20000~350000mg / L. The characteristics of high salt make it difficult to use biological technology for treatment, and it is also difficult to use membrane separation, electrodialysis separati...

AI Technical Summary

Problems solved by technology

For a long time, most of the high-salt glycerol-containing wastewater such as epoxy resin production wastewater in my country has always been in a state of excessive discharge, and the high-concentration sodium chloride and glycerin have not been recycled, which not only pollutes the environment, but also causes great damage to resources. waste

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