Research About The Removal Methods Of Lead In Water And Shellfish Aquatic Products

Lead was one of the metals in early use.When the Pb???in the human body reaches a certain amount,not only affects our normal life,serious when still can endanger life.At present,with the rapid development of industry,industrial wastewater containing lead ions has been discharged into some waters in large quantities,making many aquatic products seriously polluted.Therefore,the removal of Pb???in water and aquatic products has become an important research subject.Two kinds of adsorbents,TETA-Pectin-Fe₃O₄ and SA-Pectin-Fe₃O₄,were prepared and characterized.The main experimental contents and results are as follows:?1?Structural characterization of two materials with instruments:SEM,FT-IR,XRDand TGA.It can be seen from the results that the two modified materials were successfully synthesized,moreover,the surface of the material is rough and porous,and the thermal stability of TETA-Pectin-Fe₃O₄ particles is better.?2?Through the study of the adsorption kinetic model and isothermal adsorption model of the two modified materials,it is shown that the adsorption of the two materials to lead is faster,the adsorption reaches equilibrium about400-600min,the equilibrium adsorption capacity of TETA-Pectin-Fe₃O₄ is76.73mg/g,the equilibrium adsorption capacity of SA-Pectin-Fe₃O₄ is64.21mg/g,and the adsorption process conforms to the quasi second-order kinetic model,and the correlation coefficient R² is greater than 0.99.Langmuir isotherm model is suitable for fitting the adsorption isotherm,and the correlation coefficient R² is greater than 0.98.?3?In this paper,single factor and orthogonal experiments were carried out to explore the best adsorption conditions of two kinds of synthetic materials for lead in aqueous solution.The optimal adsorption conditions of TETA-Pectin-Fe₃O₄ orthogonal experiment are:the adsorption time is 150min,the initial concentration of Pb???is 200mg/L,pH=7,temperature is 40^oC,and the dosage of adsorbent is 10mg;the optimal adsorption conditions of SA-Pectin-Fe₃O₄ orthogonal experiment are:the adsorption time is 120min,the initial concentration of Pb???is 150mg/L,pH=6,temperature is 50^oC,and the dosage of adsorbent is 10mg.?4?In the desorption regeneration experiment,0.1mol/L EDTA was used as the eluent.After five or so cycles of adsorption on TETA-Fe₃O₄-Pectin and SA-Fe₃O₄-Pectin,the removal rate can still reach more than 60%.?5?Two kinds of modified adsorbents were applied to the adsorption of lead in enzymatic hydrolysates of clams,clams,clams,clams,scallops and so on.The removal rate of lead was over 75%,and the effect was very good.