Preparation And CDharacterization Of Seriesw Nocel Pollutant-sorbents And Research Of Their Applications In Water Environment

With the pollution caused by urbanization and industrialization becoming more and more severe, heavy metal pollution has been a global problem. Heavy metals have obvious harm to human and other organisms. Excessive heavy metal in human bodies can cause many kinds of diseases. Therefore, removal of heavy metal has become an important task for national and international research, and dealing with heavy metal pollution in water has become an important task of protecting environment to each country.In this paper, research for heavy metal pollution has been done, and prepared series novel environmental friendly materials to remove heavy metals in water. The contents of this study are main made up of two parts:In the first part , Magnetic nano-particles coating with carboxymethyl chitosan(use CMC-MNP for short below) were synthesized by use carboxymethyl chitosan(CMC) to modify magnetic nano-particles(MNP). CMC- MNP were characterized by FT-IR, TEM, XRD, and DTA-TG. The results show that CMC coated on MNP well, the particle size of CMC-MNP is about 15 nm and they disperse well. Then explore their absorb ability by using prepared CMC-MNP to absorb cobalt ions, and Then the effects of several factors such as stirring time, pH value, temperature and dosage of CMC-MNP are researched in order to find out their effects on the efficiency of treatment, then get the best conditions of absorption after analyzing, the results show that the best effect can get when temperature is 315K, pH is 6, stirring time is 60 min, and the dosage of CMC-MNP is 84 mg in 50mL 10mg/L cobalt ion solution, and the removal percentage can reach 91%.In the second part, we cover Fe₃O₄ onto the surface with SiO₂ and then use cetyltrimethyl ammonium bromide (CTAB) surfactants as structure-directing agents, cove it with another layer of mesoporous SiO2, and form a core-shell magnetic silica (Fe₃O₄@mSiO₂@nSiO₂,use MS for short below). Then we modify MS with–SH to form a novel adsorbent support (MMS). Characterise the material by FT-IR, SEM, TEM, XRD, XPS, VSM, and BET. The results show that the prepared materials are mesoporous and magnetically, with a diameter of 300–450 nm, a surface area of 469 m² g^-1, a pore size of 3.1nm, and a saturation magnetization of 28.1 emu g^-1. This mesoporous magnetic material has a strong ability to absorb, and has different absorb ability under different conditions. MMS was applied to adsorb the Co²⁺ in the solution. The results turned to be: After reacting for 8 h, the reaction reached adsorption equilibrium. pH value was proved to have great influence on adsorbing capacity, and the pH bigger and the result better. As Cd2+concentration increased, supports adsorbent capacity went up gradually. This adsorption reaction was proved to be highly fitted with a Langmuir adsorption isotherm equation. The adsorption capacity to Cd²⁺ is 172.4mg g^-1. After absorb, the used microspheres can be easily separated from the mixtures by adding an external magnetic field, more over, they are environmental friendly and can be recycled. All these peculiarity are accord with green chemistry.