Synthesis Of Manganese Ferrite Composites And Their Superior Performance For Pb²⁺ And Cd²⁺ Removal

It is well known that heavy metal pollution has attracted much attention because of its non biodegradability and high toxicity.Once heavy metal ions enter into the water environment,they can not only be biodegraded,but also will eventually accumulate in the organisms through the food chain,which will destroy the normal physiological and metabolic activities of the organism and cause serious physiological or neurological damage,and may lead to canceration.Ferrite nanoparticles are one of the most attractive adsorption materials because of their unique paramagnetic,strong adsorption capacity and easy recovery,but the adsorption material has the disadvantages of poor monodispersity and easy aggregation.Amina-manganese ferrite nanoparticles and manganese ferrite/biochar composites are synthesized from manganese ferrite nanoparticles of magnetic,which are applied to remove Pb²⁺and Cd²⁺from wastewater.The research contents and conclusions are as follows:Amina-manganese ferrite nanoparticles:Amin-ferromanganese nanoparticles were synthesized by one-step hydrothermal method using 1,6-ethylenediamine as N source.The surface roughness and agglomeration of the nanoparticles were weakened by characterization analysis,and the constituent elements of these materials were N,O,Mn and Fe.The adsorption experiments of Pb²⁺and Cd²⁺showed that amina-manganese ferrite nanoparticles were good adsorbent materials.When pH was5 and 7 respectively,the adsorption of Pb²⁺and Cd²⁺on amina-manganese ferrite nanoparticles reached equilibrium at 60min.With the increase of initial concentration,the adsorption capacity of amina-manganese ferrite nanoparticles on Pb²⁺and Cd²⁺increased gradually,and finally reached the balance.The adsorption process of amina-manganese ferrite nanoparticles for adsorption of Pb²⁺and Cd²⁺conforms to the quasi secondary adsorption dynamic model and Langmuir adsorption isotherm model,which belongs to single layer chemisorption.After 5 desorption-adsorption,there is still high adsorption and magnetic stability.The mechanism of adsorption of Pb²⁺and Cd²⁺on aminated manganese ferrite nanoparticles is studied by XPS.Pb²⁺and Cd²⁺may react with the oxygenated and nitrogenous functional groups on the surface of amina-manganese ferrite nanoparticles.Manganese ferrite/biochar composites:manganese ferrite/biochar composites were synthesized by using biological carbon as the carrier,which loaded on manganese ferrite.By the analysis of acid resistance and characterization,manganese ferrite/biochar composites have good stability and magnetic properties.manganese ferrite/biochar composites have been applied to the treatment of Pb²⁺and Cd²⁺,and have good adsorption properties.When pH is 5 and 7,the adsorption of Pb²⁺and Cd²⁺by manganese ferrite/biochar composites is balanced in 60min.With the increase of initial concentration,the adsorption capacity of manganese ferrite/biochar composites on Pb²⁺and Cd²⁺increased gradually,and finally reached the balance.The adsorption process of manganese ferrite/biochar composites for adsorption of Pb²⁺and Cd²⁺conforms to the quasi secondary adsorption dynamic model and Langmuir adsorption isotherm model,which belongs to single layer chemisorption.The results of 5desorption-adsorption experiments show that manganese ferrite/biochar composites have good regeneration performance.Through the characterization analysis of XPS adsorption mechanism of Pb²⁺and Cd²⁺on manganese ferrite/biochar composites,that showed that Pb²⁺and Cd²⁺may be related to manganese ferrite/biochar composites biological surface oxygen-containing functional groups and chemical reaction,in addition,Pb²⁺with manganese ferrite/biochar composites material of biological electrostatic adsorption.