LAUSR

Abstract Large amount of N-heterocycles are produced by various industries and most of them are extremely harmful toxicants. In the current work, the selective removal of quinoline and pyridine from their binary diluted aqueous solution by using a novel technology of foam fractionation with salt was investigated. In continuous foam fractionation, quinoline and pyridine could exert competitive adsorption when sodium dodecyl sulfate (SDS) was used as the collector. The influence mechanism of the salts on the competitive adsorption of quinoline and pyridine were elaborated through adding monovalent metal salts (NaCl and KCl) and bivalent metal salts (CaCl2 and MgCl2). In the stripping mode of foam fractionation with or without KCl, the competitive adsorption between quinoline and pyridine were determined by using Thomas adsorption kinetics models. Finally, a novel two-stage foam fractionation technology was developed to successively remove of quinoline and pyridine from their binary aqueous solution. The removal percentage and purity of quinoline in the first stage were 90.50% and 89.57%, respectively. After a second stage foam fractionation, the removal percentage of pyridine and the total removal percentage of quinoline could reach as high as 94.72% and 97.38%, respectively.