| Organic amines are common toxic organic pollutants among many pollutants and can be widely found in the environment.They can enter the human body through various means.Longterm exposure to some organic amines can lead to chromosomal structural abnormalities,and some of them are even precursors of carcinogensto lead to cancer.Adsorption method has been widely been paid widely attention for it effective and convenient in water pollution treatments.Magnetic nano adsorbents have become a research hotspot in recent years because of the advantages of easy separation and recovery.In this paper,magnetic nanocomposite adsorbents were prepared from industrial wastes to solve the increasingly serious water pollution problems.The concept of "usingwaste residue to treat water pollution" is adopted.Based on it,not only it can solve the problem of water pollution,but also it can provide a new way for exploring high value and green application of metallurgical minerals and their wastes.Firstly,the nano-silicas were prepared respectively from sodium silicate and laterite nickel slag by carbonation decomposition reaction.The structures and properties of the nano-silicas were characterized by SEM,XRD and BET.The thermodynamics and kinetics of adsorption of organic amines by nano-silica were studied.Further,the adsorption properties of magnetic nanocomposite adsorbents on organic amines were studied.The preparation of magnetic nanomaterials is as follows:Firstly,the magnetic core is prepared by hydrothermal method from the soluble salts of nickel and iron and from the laterite nickel ore,respectively.And then,the nano-silica prepared from laterite nickel slag is coated to the two magnetic cores.The structures and properties of the magnetic nanocomposite adsorbents were characterized by SEM,XRD,BET and VSM.The thermodynamics and kinetics of adsorption of organic amines by magnetic nanocomposite adsorbent were studied.Investigation results show that the four adsorbents we synthesized have obvious adsorption on organic amines;The equilibrium adsorption capacity increases with the initial concentration of the solution,but the increase is not proportional;And increasing temperature of the environment is beneficial to the adsorption;Compared to Langmuir model,the adsorption process preferred Freundlich model,occuring on the inhomogeneous surface,and adsorption energy is unevenly distributed on the surface of the adsorbent;The adsorption process is spontaneous and endothermic reaction;The kinetic adsorption data could be described by pseudo-second-order reaction;Furthermore,adsorption kinetics data were analyzed by WeberMorris model.The results suggest that the adsorption process was regulated by both surface and intraparticle diffusion processes. |
