Synthesis Of Carboxylic Acid Chelating Agent And Modification On The Surface Of Nanometer Fe₃O₄

Traditional heavy metal wastewater treatment agent will produce sludge, and the sludge will dissolve out again in case of pH change, which will causing secondary pollution. Magnetic separation technology is a new technology about environmental protection, with advantges not only speedy, efficiencial, stable, but also equipment simple, operation easy and convenient for management and maintained. The most important merite is that the technology would be little infulenced by temperature and climate change, can avoid secondary pollution to the environment and reduce chemicals using.In order to solve the traditional sewage treatment agent recycling problem, improve the metal chelating agent of water treatment efficiency, avoid the secondary pollution, this paper have designed amino polycarboxylic acid type chelating agent, which modified on the surface of the magnetic Fe3O4nanoparticles, and have evaluated the effect of heavy metal chelating. It includes the following4aspects:1. Overviewing categories, action principle, application of chelating agent and current situation of sewage treatment technology at home and abroad. Highlight the mechanism and differents types about the surface modification of magnetic nanoparticles.2. With ethyl bromide as raw material react with amino alcohols, obtained4bromo carboxamide chelating agent, and explore the hydroxyl bromination reaction conditions.3. Magnetite nanoparticles Fe3O4coated with (3-aminopropyl) triethoxysilane (APTES) are prepared by silanization reaction. Using FT-IR and potentiometric titration technology, the effect of activation method, solvents, feeding ratio, reaction temperature, and time on the modification of Fe3O4nanoparticles by-NH2group are exerted. Results show that the nanoparticles Fe3O4have been successfully coated by APTES, and the optimized experiments are proceeded at60℃for11h with feed ratio3:8in the presence of ethanol-water as solvent, where the concentration of surface-NH2group reach up to ca.1400±50μmol·g-1.4. Modifing the surface of Fe3O4/APTES composite nanoparticles by the carboxamide chelating agent. The functionalized particles were characterized through IR. Have studide the regeneration ability and Pb2+chelating effect of Fe3O4magnetic nanoparticles. The results show that, the regeneration effect of chelating agent modified Fe3O4magnetic nanoparticles is good,the efficiency of bifunctional chelating to pb2+is higher.