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羟基自由基致死空间有害微生物的实验研究

Experimental Studies on Killing Space Harmful Microorganisms by Hydroxyl Radical

【作者】 赵董艳

【导师】 白敏冬;

【作者基本信息】 大连海事大学 , 环境工程, 2008, 硕士

【摘要】 空间有害微生物给人类健康和动植物生存带来威胁。其传播途径主要是接触传播和空气传染,因此对表面和空气中有害微生物的杀灭显得尤为重要和迫切。常用治理技术不能行之有效地快速、无污染地消除空间有害微生物,防止疫情的扩散。由于羟基自由基(·OH)具有快速、无选择性、高效、无污染等特点,弥补了常规方法的不足,但现有的·OH制备方法仍存在很多缺陷。本文采用强电场电离放电方法解决了高浓度·OH生产规模化等问题,满足了实际应用的需要。采用·OH溶液对细菌、真菌、芽孢中的典型有害微生物进行平面喷洒灭菌实验,结果表明·OH溶液是无选择性、用量少、高效、快速、绿色环保的灭菌剂,可满足平面灭菌的要求。通过正交实验分析并讨论了操作条件对杀灭效果影响,大小顺序为:喷洒密度>·OH浓度>作用时间。优化了完全杀灭有害微生物的操作参数:·OH溶液阈值浓度≤1.0 mg/l、喷洒密度21μl/cm~2,作用时间≤4 s。·OH溶液在适当条件下可使微生物彻底消失,无细胞残体残留。探讨了·OH与细胞壁、细胞膜、胞内物质等的重要组成单元和功能物质发生不可逆反应,进而破坏细胞基本结构和功能,导致微生物死亡的机理。对·OH灭菌的生物学过程进行实验研究和机理分析发现:·OH灭菌是由外而内进行的;·OH作用于细菌和真菌的细胞壁和细胞膜,破坏细胞壁和细胞膜的完整性而使其破裂,作用于芽孢的芽孢壳、芽孢膜、皮质和芽孢壁而使其破损;胞内物质外泻,并快速消失,大片的细胞膜在表面张力的作用下收缩成球状;剩余·OH还可能与剩余的细胞残体反应或分解而消失。·OH溶液能很好地杀灭表面的细菌、真菌和芽孢,且无二次污染,为空气消毒灭菌和大空间内灭菌研究奠定了基础。

【Abstract】 Harmful Microorganisms in space have become a major threat to the health of human and the survival of propagation.They transmit by contact and by air.So killing harmful microorganisms in the air and on the surface is particularly important and urgent.In fact there is no effective way to fast,effective and nonpolluting eliminating harmful microbes to prevent the spread of the epidemic.Because killing harmful microorganisms by hydroxyl radical(·OH) possesses following advantages:fast, nonselective,effective,nonpolluting.It makes up for the shortcomings of the conventional methods.However there are many problems in·OH producing methods. In this thesis,strong ionization discharge plasma technology is used to produce high concentration of·OH solution,which solves the problem of production in scale and other issues,to meet the needs of practical applications.·OH solution is sprayed on the surface with typical bacteria,fungi or spore in sterilization experiments.The results show that·OH solution is a nonselective and efficient and fast and green sterilizing agent,which can be employed satisfactorily in broad areas.The effects of operating conditions on sterilization are discussed and analyzed,and the order is:spraying density>·OH concentration>action time.And the optimal operating parameters have been obtained:spraying density 21μl/cm~2, threshold concentration of·OH solution=1.0 mg/l and action time=4 s.So sterilization technology using·OH solution can meet the requirement of high efficiency and less use level and rapid sterilization.Under the suitable conditions,·OH solution can further act on cellular relict,which leads to complete disappearance of microorganism.The principium of elimination is expounded that·OH can react with important components and functional materials of the cell wall,cell membrane and the intracellular material to undermine the basic structure and function of cells,resulting in the death of microorganisms.On the basis of experiments,observation and analysis of the mentioned mechanism,the sterilization process using·OH is analyzed and described preliminarily as follows:(1)·OH damages cells from outside.(2)·OH acts on cell wall and cell membrane of bacteria and fungi to cause damage to the integrity of its structure,and then bring the cell to rupture;also·OH destroys carcasses,cortex, membrane and wall of spores.(3) Then intracellular substances leak,and quickly disappeared.(4) Large membranes contract into spherical surface under surface tension. (5) Surplus·OH disappears by reacting with cellular relict or decompose.·OH solution could well exterminate bacteria,fungi and spores on surface,and don’t bring secondary pollution,which lays the foundation for air sterilization and space sterilization.

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