Abstract：
Determining the role of micro-nanobubbles (MNBs) in controlling the risk posed by pathogens to soil and groundwater during reclaimed water irrigation requires clarification of the mechanism of how MNBs block pathogenic bacteria. In this study, real-time bioluminescence imaging was used to investigate the effects of MNBs on the transport and spatiotemporal distribution of bioluminescent Escherichia coli 652T7 strain in porous media. The presence of MNBs significantly increased the retention of bacteria in the porous media, decreasing the maximum relative effluent concentration (C/C0) by 78 % from 0.97 (without MNBs) to 0.21 (with MNBs). The results suggested that MNBs provided additional sites at the air-water interface (AWI) for bacterial attachment and acted as physical obstacles to reduce bacterial passage. These effects varied with environmental conditions such as solution ionic strength and pore water velocity. The results indicated that MNBs enhanced electrostatic attachment of bacteria at the AWI and their mechanical straining in pores. This study suggests that adding MNBs in pathogen-containing water is an effective measure for increasing filtration efficiency and reducing the risk of pathogenic contamination during agricultural irrigation.
摘要：
确定微纳米气泡（MNBs）在控制再生水灌溉过程中病原体对土壤和地下水的风险中的作用，需要澄清MNBs如何阻止病原菌的机制。在这项研究中,实时生物发光成像用于研究MNBs对多孔介质中生物发光大肠杆菌652T7菌株的运输和时空分布的影响。MNBs的存在显著增加了细菌在多孔介质中的滞留，将最大相对流出物浓度(C/C0)从0.97(不含MNBs)降低到0.21(含MNBs)。结果表明，MNB在空气-水界面（AWI）提供了额外的细菌附着位点，并充当物理障碍以减少细菌通过。这些影响随环境条件如溶液离子强度和孔隙水速度而变化。结果表明，MNB增强了细菌在AWI处的静电附着及其在孔中的机械应变。这项研究表明，在含病原体的水中添加MNBs是提高过滤效率和降低农业灌溉过程中病原体污染风险的有效措施。
