Method for absorbing sulfur dioxide desorption barren solution with citrate purification method

The invention relates to a method for absorbing a low-concentration sulfur dioxide desorption barren solution with a citrate purification method. The method comprises the following steps of: making desorption barren solution flow through a three-chamber electroosmosis system formed by the mode of combining an anion selection membrane with an anode and combining a cation selection membrane with a cathode; under the action of an ultrasonic wave generation system, making sulfate radical ions in the desorption barren solution and a citric acid radical decomposition product enter an anode region through the anion selection membrane; forming dilute sulphuric acid by the sulfate radical ions under the action of anodic oxidation, oxidizing the citric acid radical decomposition product into carbondioxide and water and forming dilute sulphuric acid in an anode region; making sodium ions and hydrogen ions in the desorption barren solution enter a cathode region through the cation selection membrane to obtain sodium hydr