化学消毒剂对污水处理系统中游离细菌表面zeta电位的影响

为了解化学消毒剂对污水处理系统中游离细菌表面电位的影响,以探讨化学消毒剂对污泥中细菌杀灭机理,采用细胞表面电位测定方法,对活性污泥中常见游离菌的表面zeta电位进行了检测。结果,甲醛、戊二醛和高锰酸钾可使活性污泥中葡萄球菌、螺旋菌、杆菌、双球菌、荚膜细球菌和微球菌等6种游离细菌表面zeta电位增加;过氧化氢则使此6种游离菌表面zeta电位先增加后降低。细菌表面zeta电位增大,反映此类消毒剂与细菌胞壁肽聚糖结构中肽链上亚氨基和自由氨基发生酰化作用,从而致死细菌。细菌表面zeta电位减小,反映细胞壁的磷壁酸和脂多糖成份中的脂质基被氧化成过氧链,因此破坏了细胞壁的致密结构,改变了菌体代谢致细菌死亡。结论,通过测定细菌表面zeta电位变化,可了解消毒剂对污泥中游离菌初步杀菌机理。

INFLUENCE OF CHEMICAL DISINFECTANT ON ZETA POTENTIAL OF FREE BACTERIAL SURFACE IN SEWAGE TREATMENT SYSTEM

In order to know the influence of chemical disinfectant on free bacterial surface potential in sewage treatment system for exploring the mechanism of killing bacteria in sludge by chemical disinfectant,cell surface electric potential measuring method was used to measure the zeta potential of common free bacterial surface in active sludge.Results: Formaldehyde,glutaraldehyde and potassium permanganate could cause increase in surface zeta potential of 6 kinds of free bacteria including Staphylococcus,Spirillum,Bacillus,Diplococcus,Micrococcus capsulatum and Micrococcus in active sludge.Hydrogen peroxide caused increase and then decrease in surface zeta potential of these 6 kinds of free bacteria.Increase in bacterial surface zeta potential reflected that this kind of disinfectant caused acylation of imino-group and free amino-group on peptide chain in bacterial wall peptidoglycan structure,leading to death of the bacteria.Decrease in bacterial surface zeta potential reflected that the lipid group in teichoic acid and lipopolysaccharide components of cell wall was oxidized to become peroxy-chain,thus the dense structure of the cell wall was destroyed and the bacterial metabolism was changes,leading to bacterial death.Conclusion: By measuring the changes of bacterial surface zeta potential,the primary germicidal mechanism of disinfectant in killing free bacteria in sludge can be understood.