霉菌过度孳生威胁人与物资安全。霉菌对湿度极为敏感，南方梅雨季的持续高湿可激发自然界释放大量霉菌孢子并气溶胶化侵入室内，使发霉问题加重。与非生物颗粒不同，霉菌气溶胶的危害主要取决于两大因素：浓度和活性。拦截霉菌虽可降低浓度，但并未消灭活性，所拦霉菌不但继续向气流释放霉毒素(空调“霉味”)，还在空调内持续生长，成为新污染源。而除湿空调中盐溶液的反渗透作用虽可使捕集的霉菌脱水休眠，但在细胞壁/膜的保护下，此时霉菌结构完整并保有复活性，重新气溶胶化存在二次传播的风险。因此，突破霉菌壁/膜是提高除湿空调灭霉性能、彻底解决发霉问题的关键。为此，本项目在溶液脱水霉菌时引入超声波，通过在溶液中产生伴有温度和压力突变及强剪切力的空化效应，迅速攻破霉菌壁/膜而高效灭霉。深入研究超声空化对灭霉的强化机理，分析其灭霉效率及影响因素，探讨适用的超声波特性与灭霉优化方案。成果可为有效增强梅雨季空调灭霉效果提供新方法。

Indoor mold threatens the occupants’ health and properties’ safety. Mold is extremely sensitive to air humidity. During the plum rain season in South China, a large number of molds and spores can be triggered and released from the natural environment into the air as mold aerosols. Due to their small size (in micrometer), the aerosols can easily invade the indoor through the air-conditioning systems. Differed from the non-living particles, the purification of mold aerosols must concern the following two factors: concentration and vitality. Although the molds’ concentration drops by the interception in the HVAC system, they are still vibrant. The intercepted molds not only keep releasing mycotoxins into the airstream (“moldy smell”) but also continue growing inside the air-conditioning system. What is worse, the newly-grown molds become the new pollution source. By contrast, via the significant reverse osmosis of liquid desiccant, the captured mold can be dehydrated and dormant in liquid desiccant air-conditioning systems. However, being protected by the cell wall/membrane, the dehydrated molds tend intact and recover soon after. The undesired recovery raises the risk for the mold aerosols to spread again. Therefore, it is the prerequisite to break through the molds’ cell wall/membrane for promoting the mold inactivation. To this end, this project introduces the ultrasound, which is harmless to human beings, to promote molds inactivation in the liquid desiccant air-conditioning system. With the strong cavitation effects generated by ultrasound in the liquid desiccant, i.e., the sudden local changes in temperature and pressure, as well as the strong shear forces, the cell wall/membrane of mold would be broken through. Thus, the barrier is crossed, and the mold will be killed efficiently. The project will be carried out with experimental and theoretical studies in terms of the following aspects: 1) clarify the mold inactivation mechanism by the ultrasound in liquid desiccant; 2) figure out the inactivation efficiency and the influencing factors; 3) explore the applicable ultrasound properties and build the optimal conditions for mold inactivation. The project’s results will provide a new method for the efficient mold inactivation in liquid desiccant air-conditioning systems and cut off the outdoor mold invasion during the plum rain season.