In this study, rapid inactivation of Escherichia coli (E. coli) by surface micro-discharge (SMD) plasma is studied by comparing the inactivation effects in air with and without water droplets (WDs) under different distances (d) between the samples and the grounded electrode. The discharge current, discharge power and spatial–temporal developments of SMD are also compared. The pH value, conductivity and the concentrations of reactive oxygen and nitrogen species (RONS) of condensed water are determined with the presence of WDs. In addition, the role of water vapor on the sterilization process is analyzed by evaluating the inactivation efficiency of E. coli treated with plasma effluent through the gas outlet. The measurements imply that the variation in discharge power may not be the main factor affecting E. coli inactivation in WD-tuned air. The results of sterilization display that with the presence of WDs, the log value of remaining E. coli on the surface of the sample can be rapidly reduced to 0.05 in 5 s by SMD plasma treatment as the sample surface stained with E. coli backing on the grounded electrode (GND) at d = 1.1 mm. However, a significant decrease in E. coil survival without WDs takes more than 30 s or longer. It also suggests that WD-tuned SMD can significantly contribute to the generation of reactive species associated with water, thus leading to the rapid inactivation of E. coli. These species may be transferred to the surface of the treated samples through air or water clusters.

本研究通过比较不同距离（ d）下样品与无水滴（WDs）在空气中的灭活效果，研究了表面微放电（SMD）等离子体对大肠杆菌（E.coli ）的快速灭活作用。接地电极。还比较了 SMD 的放电电流、放电功率和时空发展。冷凝水的 pH 值、电导率和活性氧和氮物质 (RONS) 的浓度是在存在 WD 的情况下确定的。此外，通过评估大肠杆菌的灭活效率，分析了水蒸气对灭菌过程的作用。通过气体出口用等离子体流出物处理。测量结果表明，放电功率的变化可能不是影响WD 调谐空气中大肠杆菌灭活的主要因素。灭菌结果表明，在存在WDs的情况下，样品表面沾有E.coli背衬，通过SMD等离子处理，样品表面残留E.coli的log值可在5s内迅速降至0.05。 d  = 1.1 mm处的接地电极 (GND) 。然而，E.线圈显着减少没有 WDs 的生存需要超过 30 秒或更长时间。它还表明 WD 调谐的 SMD 可以显着促进与水相关的活性物质的产生，从而导致大肠杆菌的快速灭活。这些物质可以通过空气或水簇转移到处理过的样品的表面。