Preparation Of Novel Type Of Magnetic Adsorbent And Its Adsorption Performance For Heavy Metals/Dye In Water Environment

Eco-environmental protection has received social attention,and the treatment of environmental water pollutants is an important research direction in the field of ecology.The pollution of typical inorganic heavy metals and organic waste dyes is becoming more and more serious,and it has become a problem of environmental management today.It is urgent to carry out the treatment of typical pollutants.Among them,the research on new functional adsorbents for removing heavy metals and organic dyes has certain application and practical significance.In this paper,organic natural biomass material-sodium alginate and inorganic nanotube material-halloysite are used as raw materials to modify the surface of the magnetic material by chemical precipitation method and silanization reaction to prepare an aminated magnetic material,which is then embedded by titration.The method puts the aminated magnetic material into the sodium alginate gel spheres,obtains a new organic-inorganic magnetic composite gel adsorbent,and carries out the adsorption and removal of heavy metal ions and dye molecules by the gel spheres,and establishes the relevant adsorption theoretical model.The main research work is as follows:(1)The magnetic particles(MNP)prepared by the ion co-precipitation method are used as a carrier for silanization reaction to synthesize magnetic nanoparticles(AM)having an amino terminal.A new type of magnetic gel composite microspheres(SA @ AM)rich in amino,hydroxyl and carboxyl multifunctional groups were prepared by coating sodium alginate(SA)on the surface of magnetic particles with electrostatic effect.Use Fourier transform infrared spectroscopy(FTIR)to test the infrared spectrum of intermediate and final products,elemental distribution of the test product by elemental analyzer,X-ray diffraction(XRD)to characterize the product crystal form,scanning / transmission electron microscope(SEM / TEM))Observe product morphology,vibrate the sample magnetometer(VSM)to characterize the magnetic response of the product,and carry out research on the adsorption performance of the product to heavy metal ions.The experimental results show that the successfully prepared target functional polyelectrolyte ball(SA @ AM)has a paramagnetic magnetite crystal form,and the size of the SA @ AM gel ball is between 1.5 and 2 mm;the magnetization of MNP,AM,SA @ AM The values are 13.8,13.4 and 6.85 emu·g-1,respectively.Adsorption experiments showed that the maximum adsorption amount of heavy metal Pb2 + by SA @ AM was 105.82 mg·g-1,and the adsorption mechanism was more in line with the Langmuir isothermal adsorption model.Repeated adsorption-desorption experiments showed that the removal rate of Pb(II)by SA @ AM was ?76%.This shows that the new type of sodium alginate magnetic composite gel ball has excellent adsorption capacity for heavy metal ions Pb(?),and the magnetic gel ball has good regeneration performance.The relevant results have important reference significance for the preparation of green pollution-free bio-based magnetic gel-type adsorption materials.(2)Using Halloysite nanotubes(HNTs)as carriers,magnetic particles(MNP)were attached to the halloysite surface by ion co-precipitation method to obtain magnetic halloysite(MHNT),and aminoterminal amination was synthesized by silanization reaction.Magnetic halloysite(AP-MHNT).Aminated magnetic halloysite is coated in sodium alginate gel spheres using ionic interactions to obtain polyfunctional organic-inorganic composite magnetic coagulation rich in amino,carboxyl and hydroxyl groups.Gel ball adsorbent.Fourier transform infrared spectroscopy(FT-IR)was used to analyze the product groups,and the elemental analyzer was used to characterize the product element distribution,Xray diffractometer(XRD)was used to characterize the product crystal form,and scanning / transmission electron microscopy(SEM / TEM)was used to analyze the sample morphology,UV Spectrophotometer to test material adsorption performance.The experimental results show that the successfully prepared target functional magnetic gel ball(SA @ MHNT)exhibits good magnetic response,and the size of the SA @ AM gel ball is between 0.5 and 1 mm.Adsorption experiments show that the new organic-inorganic magnetic composite gel spheres have excellent adsorption capacity for direct green B dyes,and the maximum adsorption amount can reach 174.5 mg·g-1.the adsorption mechanism of gel spheres for direct green B is suitable for Langmuir Isothermal adsorption model;adsorption kinetics can be described by quasi-second-order kinetics;repeated adsorption-desorption experiments show that the removal rate of direct green B by SA @ MHNT is ?73%,indicating that the new magnetic gel spheres have good reuse performance.The results provide important value for the preparation of new organic-inorganic composite adsorbents.The research work of this thesis provides applied basic research on the treatment of typical pollutants in the ecological environment,and provides references for the preparation of green,cheap,and highly reusable new magnetic adsorption gels.At the same time,the prepared new magnetic organic-inorganic composite gel sphere provides a feasible solution for the study of the removal of heavy metals and organic dyes in the actual ecological environment,and has the value of research.