静磁场对硫酸盐还原菌生物膜形成过程的影响

Influence of Static Magnetic Field on Formation of SRB Biofilm

采用铂片微排电极研究了硫酸盐还原菌(SRB)生物膜在有无磁场环境下的电化学行为。结果表明:无磁场下铂片电极表面覆盖一层很厚的生物膜,通过显微镜观察厚度为141.4μm,生物膜电阻较大,生物膜脱吸附过程进行时间较长,生成的腐蚀性产物较多。磁场存在下SRB细菌不容易在铂片电极表面吸附,进而形成的生物膜较薄(厚度为67.06μm),生物膜在很短时间内达到了脱吸附平衡状态,从而生物膜内腐蚀性物质较少,对基体的腐蚀作用较弱。电荷传质电阻Rct表明,磁场的引入极大地阻碍了电极表面电荷的运动,从而影响了电化学过程的顺利进行。

The electrochemical behavior of sulfate-reducing bacteria(SRB) biofilm was investigated by means of micro electrode of platinum in the absence and presence of a static magnetic field(SMF) respectively. The results showed that a 141.4 μm thick biofilm with high resistance(Rf) was form on the surface of Pt metal in the absence of SMF, and the process of adsorption and desorption of the biofilm took a long time resulting in corrosion products on the Pt foil surface. In the presence of SMF, it was hard to adsorb on the surface Pt foil for SRB and the biofilm was thinner(the thickness was 67.06 μm). The adsorption and desorption of the later biofilm proceeded rapidly and reached an equilibrium state after short time indicating that little amount of corrosion products was generated in the biofilm, which means that the corrosion rate of the metal beneath the biofilm is lower. The value of charge transfer resistance(Rct) suggested that the applied SMF might greatly suppress the movement of surface charge, thus affect electrochemical process.