Microorganism contaminants removal in a liquid desiccant dehumidification system

Abstract

The main focus of this research is to estimate the ability of a liquid desiccant (LD) system operation to remove microorganism particles. The dehumidification performance of the LD systems generated by using a lithium chloride (LiCl) solution as the liquid desiccant material. To verify the removal performance of microorganism particles, the experimental method was divided into cases where the process air passed or bypassed the LD unit. Two types of microorganism particles, bacteria and mold, were considered for the measurement of the microorganism particles, with a minimum fan flow rate (800 m3/h). To verify the accuracy of the experiment, a duct system and an LD system were sealed with duct tape to prevent air leakage. Experimental results were obtained with a bio-contaminant sampler using a tryptic soy agar (TSA) and a potato dextrose agar (PDA). The measuring points were situated at a same distance from the liquid desiccant system inlet and outlet duct. The results show that the LD system has the ability to remove microorganism contaminants. The bacteria removal efficiencies were 77.5% and 81.3% for the sampling process air of 200 and 500 L, respectively, while the fungi removal efficiencies were 38.8% and 44.4% for 200 and 500 L, respectively, of sampling process air. In addition, experiment results show that the LD system significantly affected the removal of microorganism contaminants. When the process air passed through the LD unit, microorganism contaminants contained in the process air were inactivated by the sanitizing effect of the desiccant solution or by filtering of the LD unit.