Novel Adsorption Functionallizing Material’s Studies On Design,Preparation And Adsorption Capacity Of Cr(Ⅵ)

A large amount of industrial wastewater contains many kinds of heavy metal ions (Chromium ion),which was always considered one of the biggest threaten to humans and the environment. At present, a variety of ways, including adsorption technology has been widely used to deal with the industrial wastewater containing heavy metal ions. Recently, magnetic separation technology, which has been introduced as a particular separation method capable of quickly separating magnetic composite adsorbents from an aqueous solution via the application of an external magnetic field.The two kinds of materials with high adsorbent has been prepared in the research. Firstly, the magnetic carbon nanotubes prepared by the thermal decomposition; poly(m-phenylenediamine)-modified magnetic carbon nanotubes were synthesized by one-step chemical oxidation polymerization. Secondly, magnetic mesoporous silica nanotubes were produced from carbon nanotubes using a well-controlled programmed synthesis method; subsequently, the as-prepared magnetic mesoporous silica nanotubes nanocomposites were modified with manganese dioxide. Both materials with Cr(VI) ion as adsorbate to study their adsorption performance. During the research, the materials were characterized by different techniques, such as transmission electron microscopy (TEM), fourier transform infrared spectrogram (FT-IR), BET surface area measurement and vibrating sample magnetometer (VSM). Studying pH value, initial concentration of adsorbate, adsorption equilibrium time and temperature of the adsorption system during the adsorption process. Langmuir and Freundlich and Tempkin isothermal adsorption model were applied to established the relationship between adsorbent and adsorbate at equilibrium. Pseudo first-order pseudo second-order and the pseudo-second-order kinetic models and Intraparticle diffusion kinetic model were applied to provide valuable insight into the reaction pathways and into the mechanism of the reaction. The initial solution pH has an apparent effect on the adsorption capacity of materials. The adsorption equilibrium time strongly depended on concentration and temperature. Moreover, the equilibrium data of the composite materials as adsorbent for Cr (VI) are more in line with the Langmuir adsorption isotherm model. The kinetic data of the adsorption under all investigated conditions fitted well with the pseudo-second-order kinetic model and the overall rate processes have multi-step process. The thermodynamic parameters imply that the adsorption processes were spontaneous and endothermic. Desorption experiment shows that the materials are showing a good stability, high adsorption efficiency and recoverability.