【作者】 郑强；

【导师】 李进；

【作者基本信息】 北京交通大学 ， 环境工程， 2007， 硕士

【摘要】 在工业循环冷却水系统中,硫酸盐还原菌(Sulfate Reducing Bacteria,简称SRB)的存在是引起微生物腐蚀(Microbiologically Influenced Corrosion,MIC)的主要因素之一。本文对取自循环冷却水系统中SRB进行分离纯化后,分析了SRB在扫描电镜下的细菌形貌特征,探讨了SRB的生理生态学特性,研究了SRB的生长与生态因子之间的关系。通过探讨SRB的生理生态学特点表明:SRB适应中温生长,在35℃时生长情况最好,适宜生长温度为30-40, SRB所能耐受的pH范围较窄,其生长最适pH范围为7～8,当pH=7时生长最优。随着COD/SO42-值增加,各培养基中SO42-还原率逐渐增大。采用电化学、微生物学和表面分析方法研究了培养基中SRB对HSn70-1A、HSn70-1B、HSn70-1AB、BFe30-1-1四种铜合金的电化学腐蚀行为和腐蚀机理,探讨了硫酸盐还原菌生物膜下介质的流动状态及材料表面状态对铜合金腐蚀的影响。结果表明,SRB的存在使电极自腐蚀电位快速负移,腐蚀速率显著增加,细菌生长后期极化电阻显著降低。扫描电子显微分析(SEM)表明,在SRB作用下HSn70-1A、HSn70-1B、HSn70-1AB、BFe30-1-1四种铜合金发生严重点蚀。介质的流动状态对细菌的附着、生长具有一定的影响,加剧了腐蚀的形成和发展。铜合金在2-巯基苯并噻唑(MBT)与1,2,3-苯并三氮唑(BTA)复配缓蚀剂中预镀膜后,耐SRB侵蚀性显著提高。研究了HEDP-ATMP-TTA复配缓蚀剂在循环冷却水介质中硫酸盐还原菌作用下对HSn701-A、B30铜合金的协同缓蚀作用,讨论了药剂用量对缓蚀性能的影响,通过SRB生长曲线、静态失重法实验、极化曲线、交流阻抗谱测定探讨HEDP-ATMP-TTA复配缓蚀剂在循环冷却水介质中对HSn701-A、B30铜合金的缓蚀行为及缓蚀机理。结果表明,当循环冷却水介质中加入缓蚀剂后可以改善铜合金耐SRB侵蚀性,且随着复配缓蚀剂浓度的增加,试片腐蚀率逐渐下降,缓蚀率逐渐提高。研究了HEDP-ATMP-TTA复配缓蚀剂在电极表面的吸附特征,采用最小二乘法对缓蚀剂的吸附过程进行线性拟合,吸附结果与Langmuir吸附等温式很吻合,表明对该缓蚀剂而言,Langmuir吸附等温式可以较好地描述其吸附等温线。更多还原

【Abstract】 In the industry recirculation water system, Sulfate Reducing Bacteria （SRB） is one of the main factors which lead to Microbiologically Influenced Corrosion （MIC）. SRB was isolated and purified from the industry recirculation water system to study physiological and ecological characteristic of SRB. The morphological character of SRB was analyzed by SEM.The relationship between growing characteristic and ecological factor of SRB was studied, thus providing theoretical basis for the study of SRB control technique pointedly. The SRB population liked to grow in moderate temperature. Its optimum temperature was 30℃ and its ecological amplitude is from 20℃ to 50℃. The optimum pH is 7 and SRB grows well when pH is 7⁸.With the increase of COD/SO₄^2- in culture media, the sulfate reducing ration became large.Effects of SRB on corrosion behavior of HSn70-1A、HSn70-1B、HSn70-1AB、 BFe30-1-1 copper-alloy were studied by electrochemical, microbiology and surface analysis methods. The results showed that the free corrosion potential of the alloy shifted negatively when SRB was inoculated, the polarization resistance decreased obviously, which corresponds to an increased corrosion rate. The serious pitting corrosion occurring on the alloy surface under the action of SRB was observed by SEM. Furthermore, influence of medium flow characteristic and material surface appearance on corrosion behavior of HSn70-1A、HSn70-1B、HSn70-1AB、BFe30-1-1 copper-alloy under the biofilm of SRB were researched. It was showed that the average corrosion rate was higher and the SRB count in the biofilm was less when test piece was immersed in the flowing batch culture medium inoculated with SRB than in the static batch culture medium inoculated with SRB. Thus the flow of medium could speed up the corrosion rate. After being coated in the mixture corrosion inhibitor of MBT and BTA beforehand, the copper electrode had more positive free corrosion potential and higher linear polarization resistance in the culture medium inoculated with SRB than the one without being coated, which demonstrated that the resistance of HSn70-1A、 HSn70-1B、HSn70-1AB、 BFe30-1-1 copper-alloy against microbiologically influenced corrosion increased obviously.Synergistic effect of HEDP、ATMP and TTA on corrosion inhibition of HSn70-1A and B30 copper-alloy in the industry recirculation water inoculated with SRB was studied by means of electrochemical impedance spectroscopy （EIS） technique、weight loss method and electrochemical polarization. It had been found that there was a synergistic effect between HEDP、ATMP and TTA. The corrosion inhibiting mechanism of HEDP、ATMP and TTA was investigated. The results showed that the corrosion rate of copper -alloy descended with the enhancement of the concentration of corrosion inhibitors. Its adsorption isotherm was investigated. The results indicated that the inhibition followed the Langmuir adsorption isotherm and had good corrosion inhibition capability.更多还原