Study On Application Of Solid Phase Extraction In Removal Of Heavy Metal Ions And Organic Dyes From Environmental Water

With the development of social science,technology and the improvement of living standard,heavy metals and organic dyes are widely used in mining,metallurgy,leather making,electroplating,textile printing and dyeing.They enter the organism through the biological chain and endanger human life and health.For example,Cr?VI?can cause DNA degeneration in the body,leading to lung cancer and nasopharyngeal carcinoma.The accidental ingestion of organic dyes will cause physical discomfort.Heavy metal ions such as Pb?II?,Cd?II?,Hg?II?,Cu?II?and Ag?I?will seriously damage the brain and nervous system of human body.Therefore,on the basis of analyzing the physicochemical properties of heavy metal ions and organic dyes,a new adsorption material with good selectivity and excellent performance was developed as solid phase extractant.The solid phase extraction?SPE?behavior of heavy metal ions and organic dyes in environmental water samples was studied as the following three parts.?1?The HKUST-1 was successful synthesized and the adsorption behavior of HKUST-1 on the removal of Cr?III?was investigated.The factors affecting the removal efficiency of Cr?III?,such as pH value,oscillating time,initial concentration,temperature and interference of co-existing ions,were evaluated.The adsorption kinetics,thermodynamic behavior and adsorption isotherm were further studied.At pH 6.0-8.0,HKUST-1 were selective towards chromium?III?.Kinetic parameters fitted well with pseudo-second-order model and adsorption progress was described by Langmuir isotherm equations and spontaneous and endothermic according to the results of thermodynamics studies?rG°<0,rH°>0,rS°>0?.A new method for the removing Cr?III?from aqueous solution by porous crystal material HKUST-1 was established.?2?MoS₂ black microspheres were synthesized by hydrothermal method and theadsorption properties of organic dyes?methylene blue and malachite green?were studied.The effects of pH value,oscillation time,initial concentration,temperature,elution and ion strength on the adsorption of methylene blue and malachite green in water system were optimized.The results show that MoS₂ can selectively adsorb MB and LMG in a wide range of pH?3.0¹0.0?;the kinetic parameters fit well with pseudo-second-order model;the adsorption isotherm describes by Langmuir model;the adsorption process is spontaneous and endothermic according to the thermodynamic parameters?rG°<0,rH°>0,rS°>0?.A new technique for the adsorption of methylene blue and malachite green in water system was successfully developed.?3?MCM-41@SH was successfully prepared synthesized by sol-gel method.The adsorption and removal properties of heavy metal ions were studied,the possible adsorption mechanism was discussed,and the parameters affecting the adsorption were optimized.The experimental results show that the materials have excellent selectivity towards Pb?II?,Cd?II?,Hg?II?,Cu?II?and Ag?I?at pH 6.0.Kinetic parameters fitted well with pseudo-second-order model and adsorption progress,which was spontaneous and endothermic according to the results of thermodynamics studies?rG°<0,rH°>0,rS°>0?,was described by Freundlich isotherm equations for Pb?II?,Hg?II?and Cu?II?and Langmuir isotherm equations for Cd?II?and Ag?I?,respectively.A new technique for the adsorption of Pb?II?,Cd?II?,Hg?II?,Cu?II?and Ag?I?in water system was developed.