Flotation of Starch with Anionic, Cationic, and Nonionic Collector

—Fundamental Study on the Removal of Organic Matters from Wastewater—

Abstract

Flotation experiments of potato starch particle with several collectors; sodium dodecylsulfate and sodium oleate as anionic collectors, sorbitan monolaurate as a nonionic collector and dodecylammonium and dodecyltrimethylammonium salts as cationic collectors, were carried out. With anionic and nonionic collectors, good floatability was not observed, whereas the starch particles were successfully recovered with cationic collectors. The results indicated that the surface hydrophilic/hydrophobic property of the starch particle could be modified with cationic collectors.
The result of microelectrophoretic measurement showed that the surface of the starch particle is negatively charged in water, and therefore, cationic collector adsorbs electrostatically onto the starch particle. The results of adsorption experiment showed that neutral amine molecules adsorbed onto the starch surface and/or absorbed into the starch particle. It was suggested that capillary condensation or similar phenomena stripped neutral molecules from the water phase.