Preparation And Properties Of Magnesium Silicate/PES Membrane Adsorbent

Magnesium silicate (MgO·2SiO2·XH2O, MS2), with excellent adsorptionperformance, was successfully synthetized from sodium silicate and magnesiumchloride by hydrothermal method on the basis of laboratory’s preliminary work. TheMS2magnesium silicate and the commercially available magnesium hexasilicate(2MgO·6SiO2·XH2O, MS3) were added into polyether sulfone by using DMAc assolvent, respectively.Two kinds of magnesium silicate/PES membrane adsorbentswere prepared. The structure of membranes are characterized by analytical methods ofscanning electron microscopy analyzer, fourier transform infrared spectroscopyanalyzer, hermogravimetry and differential scanning calorimetry analyzer, universalforce measurement machine and specific surface area analyzer.The two kinds of magnesium silicate was added into PES evenly, the structure ofmagnesium silicate was changed little when they was combined with PES. At the sametime, the thermal stability of membranes was excellent.The mechanical property becomepoorer with more magnesium silicate, the mechanical proper ty of MS3/PES membranewas better than MS2/PES membrane.The maximum adsorption amount with two kinds of membranes on methyleneblue are1.85mg/cm2and1.35mg/cm2, respevtively; the membranes can adsorbmethylene blue at wide range of pH.The mechanical property of MS3/PES membraneis better and can adsorb more methylene blue at per unit area.The best conditions for the adsorption of cobalt ions: the contract time is6h, PHof the solution is acidic or alkaline. The maximum adsorption amount of MS3/PESmembrane and MS2/PES membrane are0.45mg/cm2and0.25mg/cm2,respectively.MS2/PES membrane can adsorb more cobalt ions at per unit area.The best conditions for the membranes to adsorb free fatty acids (FFA): thecontract time is4h, the temperature is25℃, the added area is50cm2with25mL biodiesel. The maximum adsorption capacity of MS3/PES membrane and MS2/PESmembrane are2.45mg/cm2and2.10mg/cm2. MS2/PES membrane can adsorb moreFFA at per unit area.Magnesium silicate/PES membrane adsorbent can remove dyestuff,heavy metal ion and FFA.When magnesium silicate was prepared into membrane,itsadsorption performance was not be affected for methylene blue, but the adsorptionperformance had fallen by half and quarter for cobalt ions and FFA.However, themembranes has a wider range of application, easier to recycle and operate, can be cut,crimped and folded. The preparation of membrane provides a new train of thoughtand method to remove dye, heavy metal ions and FFA.