Note
Self-decomposition and half-life time of gaseous hypochlorous acid
2023 Volume 28 Issue 2 Pages 65-68
Details
2023 Volume 28 Issue 2 Pages 65-68
Abstract: The concentration of the indoor gaseous hypochlorous acid (HOCl (g)) varied significantly during disinfection. The kinetics of self-decomposition of HOCl (g) was studied at temperatures within the range of 10℃ to 40℃ and relative humidity between 30% RH and 90% RH in a lab-scale confined polyvinylidene fluoride gas bag space. The decay curve of HOCl (g) , obtained by plotting the logarithm of the HOCl (g) concentration against time, was analyzed using an integrated model that showed two simultaneous first-order processes. One process was assumed to be the adsorption of HOCl (g) onto the gas bag surface, whereas the other was the self-decomposition of HOCl (g) in the gas space. The decay curve is reduced to the sum of two independent and simultaneous first-order processes. The decay rate constant for self-decomposition depended on temperature and relative humidity. The half-life time of HOCl (g) was estimated to be between 76.9 h and 116 h depending on the temperature and relative humidity conditions.
