In order to master the effect of ultrasonic pretreatment of EDTA disodium on the dissolution of calcium sulfate scale,the experiment of ultrasonic pretreatment of EDTA disodium solution to dissolve calcium sulfate scale was carried out.The scale and EDTA disodium solution were characterized and analyzed by XRD and FTIR and other methods,respectively.The results show that when the ultrasonic power is 168 W,the dissolution rate of calcium sul-fate scale is the highest,reaching 57.40%,and the solution conductivity is 20.10 mS/cm,which is 10.40 percentage points higher than that of untreated calcium sulfate scale.Ultrasonic pretreatment can increase the content of hydro-philic hydroxyl groups of associated water and hydroxyl groups of ethylenediaminetetraacetate in EDTA disodium solu-tion.The increase of hydroxyl content of associated water can promote the hydration of calcium ions at the active point on the surface of the scale,and the adsorbed water enters the scale and expands its volume.Ethylenediaminetetraace-tate ions in the solution can form calcium salt complexes with calcium ions on the surface of the scale,which promotes the migration of calcium ions on the surface of the scale to the solution and the dissolution of the scale.
关键词
超声波/硫酸钙垢/乙二胺四乙酸根/缔合水羟基/溶解/水合作用
Key words
ultrasonic/calcium sulfate scale/ethylenediaminetetraacetate/associated water hydroxyl/dissolution/hydration