Statistical evaluation of disinfection performance of chlorine dioxide and WAHW in improving indoor air quality of university library

Abstract A statistical investigation is performed into the effectiveness of two disinfectants (gaseous ClO 2 and weak acid hypochlorous water) in improving the indoor air quality in the reading room and study carrels of a university library in Taiwan. For each disinfectant, three different treatment modes are considered, namely a single-daily disinfection mode (SM), a twice-daily disinfection mode (TM), and a regular disinfection mode (RM). The results show that both disinfectants reduce the bacteria and fungi concentrations within the experimental areas. For the study carrel, with a relatively small and confined area, the weak acid hypochlorous water twice-daily disinfection mode (WTM) outperforms the ClO 2 twice-daily disinfection mode (CTM). In the reading room, no significant difference is observed in the disinfection performance of the two disinfectants due to the large and semi-closed nature of the room. An extreme negative correlation is found among the airflow velocity, the residual bacteria and fungi concentrations. Hence, it is inferred that a higher air velocity is beneficial in spreading the disinfectant within the indoor space and improving the disinfection efficiency as a result.