Mediated Electrophoresis System And The Use Of Dielectrophoresis Removal Of Heavy Metal

This paper summarizes the dielectrophoresis development and its application in many fields. Furthermore, it introduces the review of DEP progress and its advantages in inorganic particles research in detail. Moreover, it reports the removal methods of heavy metals currently. Then the theory of DEP is elaborated. In the microscopic static state device, the DEP movement of inorganic particles and inorganic particles with heavy metals are researched. In addition, a microfluidic device is manufactured and the DEP of adsorbate of heavy metals is future discussed. Based on the above, a DEP removal device of heavy metals is designed which can research the removal rate of heavy metals quantificationally.The results as follows are got by a series of experiments:1. The microscopic static state research of DEP movement of inorganic particles and heavy metalsIn the microscopic static state device, the methods and objects of DEP research are determined. Five kinds of inorganic particles are chosen, containing active carbon, hollow microsphere, kaolin, bentonite and zeolite. Of all the materials, the better materials are active carbon, hollow microsphere and bentonite which are suitable to investigate dielectrophoretic migration of the inorganic particles and heavy metals.(1) The phenomena of DEP: Positive DEP is observed both in the experiments of active carbon and bentonite. Such phenomena are observed in the experiments of active carbon and bentonite after adding heavy metals. The experiments of hollow microsphere, kaolin and zeolite take place negative DEP. But positive DEP is occurred to hollow microsphere with heavy metals. Under certain conditions, chaining particles are observed both in the experiments of active carbon and hollow microsphere.(2) Time: Time and concentration of inorganic particles between two electrodes have positive correlation.(3) Voltage: Voltage has positive relation to the concentration of inorganic particles.(4) Density of field: The width of electrodes and Density of field have negative correlation.(5) Frequency: pDEP and nDEP were observed at the different range of frequencies. Under the low frequency condition, hollow microspheres were trapped on electrode surface. But hollow microsphere intern has been trapped between the electrodes when frequency increases.(6) The shape of inorganic particles: This paper mainly research hollow microsphere because of its regular shape. Active carbon: 6-8um, hollow microsphere: 4-7um, bentonite: less then 10um.(7) Geometric design of the electrode array: In these experiments, all kinds of the tip structure of electrodes are suitable to investigate dielectrophoretic movement.(8) Diameter: The different kinds of inorganic particles have different range of diameters which are suitable to investigate DEP movement.(9) The DEP movement of different heavy metals: The relationship between voltage and diameter is different due to physicochemical properties differences of heavy metals.2. The microscopic dynamic state research of DEP trap of hollow microsphere and heavy metals(1) Velocity: The movement voltage is lowest at certain velocity.(2) Voltage: Voltage and concentration of inorganic particles have positive correlation.(3) Frequency: The trap areas of hollow microsphere are changed when frequency changes.(4) Electrode array: The concentration of hollow microspheres is diminishing on the electrode arrays along the flow in the non-uniform field.(5) The design of this device: The feasibility of the design of this device is proved by a series of experiments.3. The design of the DEP research device of heavy metalsSeveral aspects of the design of this device are reasonable, such as fluid and electric filed control. But the materials of electrode need to be future improved.