The chlorine dioxide molecule has long been used for the active purification of municipal water – the reason being is that it works, & works well. It is interesting to note that this compound is more effective than the chlorine element for breaking down pathogens – this is because of the chemical structure of the compound itself.
Although both chlorine & chlorine dioxide share the common chlorine element in their structure – this is about the only commonality between them. Both being strong oxidisers, the way in which pathogens are oxidised is very different. The chlorine dioxide molecule will selectively remove electrons, whereas chlorine will kill without discretion.
The chlorine dioxide molecule contains an uneven number of electrons within its outer shell, meaning that it can both accept & donate electrons. This compound is a gas, & is yellowish / brown in appearance. At room temperature it is very volatile & will tend to evaporate quite quickly if not contained.