不同杀菌剂对硫酸盐还原菌杀菌能力评价

采用静态培养法考察NaClO、1227和异噻唑啉酮3种杀菌剂对循环水中硫酸盐还原菌（SRB）的杀菌效果,并利用扫描电镜（SEM）观察SRB细胞形态结构变化和SS316L不锈钢试件的腐蚀形貌.结果表明,NaClO在投药12h时杀菌效果最佳,早于1227和异噻唑啉酮的24 h; NaClO抑菌持续时间较短,仅为24 h,抑制细菌生长时间最长的杀菌剂为1227,可持续1周左右;在最佳条件下,NaClO、1227、异噻唑啉酮的最大杀菌率分别为86.71％、89.70％、79.70％;随着杀菌时间的延长,SRB细胞结构由局部分解开始,7h后细胞完全解体.在接种SRB的循环冷却水中SS316L表面会生成一层分布不均的生物膜,其对SS316L的腐蚀以点蚀为主.

Evaluation of bactericidal performances of different bactericides on sulfate reducing bacteria

The bactericidal performances of three kinds of bactericides： NaC10, 1227 and isothiazolinone on sulfate reducing bacteria（SRB） in circulating water were investigated by static cultivation; the changes of SRB cellular morphology and corrosion morphology of SS316L stainless steel test specimen were observed using SEM. The results showed that, NaC10 obtained its best bactericidal performance in 12 h, which was shorter than the re- quired time（24 h） for 1227 and isothiazolinone get their optimal bactericidal performance. However, the antibac- terial duration of NaC10 was short, which was only 24 h; on the contrary, 1227 had the longest antibacterial du- ration, which was about 1 week. Under the optimal conditions, the highest bactericidal rates of NaC10, 1227 and isothiazolinone reached 86.71%, 89.70% and 79.70% respectively. Along with time, the cell structure of SRB was decomposed from partially to totally, and the cells disintegrated completely in 7 h. In the circulating cooling wa- ter with SRB inoculation, a layer of uneven distribution biofilm was formed on the surface of SS316L, which showed that, the corrosion of SS316L caused by SRB was mainly represented as pitting corrosion.