Abstract：This paper introduced the non-contact ultrasound in desiccant solution air-conditioning systems to improve the inactivation effect of liquid desiccant on airborne mold spores. A. niger spores, commonly detected in the air conditioning system, were adopted as mold samples. Experiments were performed with typical liquid desiccant (LiCl solution) under different ultrasound operating modes, i.e., non-ultrasound, non-contact ultrasound, and contacting ultrasound. Various ultrasound and LiCl conditions were also designed to clarify the improvement effects on the inactivation performance. The microbes’ viability was assessed by the methods of microbial culture and SEM observation. The results showed that non-contact ultrasound significantly enhanced the sterilization rate of mold spores in LiCl solution; the reinforced sterilization increased with exposure time to the LiCl solution and the solution’s concentration. Furthermore, the inactivation improvement was not affected the acting distance of the non-contact ultrasound to the liquid desiccant. To realize an optimal inactivation efficiency (80.8% in this paper) and avoid the possible solution crystallization, it was recommended that the liquid desiccant air-conditioning systems apply the 36% LiCl solution with non-contact ultrasound operated at a distance of 20cm for 30s. The underlying mechanism of the inactivation improvement was attributed to the increased permeability of the mold cell membranes by the ultrasonic cavitation effect that allows more ions (Li+and Cl-) to enter the cells. Compared to contacting ultrasound, non-contact ultrasound showed the advantages of not changing the liquid temperature and low power consumption (90±5W), which was 16.07% of the contact ultrasound. The results may provide a new way to improve airborne mold sterilization in liquid desiccant air-conditioning systems.
赵子恒, 杨自力, 谷雨倩, 马铭, 王昕翊, 闫鸿栩, 刘锋. 超声波隔空强化空调除湿溶液灭活黑曲霉[J]. 中国环境科学, 2023, 43(9): 4561-4567.
ZHAO Zi-heng, YANG Zi-li, GU Yu-qian, MA Ming, WANG Xin-yi, YAN Hong-xu, LIU Feng. Inactivation of Aspergillus niger in liquid desiccant solution enhanced by non-contact ultrasound. CHINA ENVIRONMENTAL SCIENCECE, 2023, 43(9): 4561-4567.
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