dc.description.abstract | Hexachlorobenzene (HeCB) is one of the notorious persistent organic pollutants (POPs). Even though its production was restricted worldwide decades ago, HeCB still remains in the environment. However, there is a scarcity of studies conducted on HeCB removal. To assist in analyzing intermediates produced in the destruction process, a method of analyzing chlorobenzene congeners has been improved. Up to now, the procedure has been successful in the analysis of chlorobenzene congeners (from tri- to hexa-). In this research, the catalytic performance of commercial V2O5-WO3/TiO2 in HeCB destruction has been studied. When the reactor temperature ranges from 160oC to 200oC, the peak of HeCB removal efficiency could be up to 99% at 200oC in the dry condition. With water vapor (20%) and in this temperature range, the highest removal efficiency was 94% at 200oC. Therefore, high temperatures can enhance catalytic activity. At higher temperatures, the gap between removal efficiencies in dry and wet conditions declines from 8% at 160oC to 5% at 200oC, which means the adverse effect of steam content on the catalyst can also be overcome. However, water vapor is still considered the factor that inhibits the catalytic performance of V2O5-WO3/TiO2. Based on the preliminary results. 1,2,4-TriCB predominates in the chlorinated by-products during catalytic destruction, and it could be almost adsorbed on the catalyst. The highest total mass of 1,2,4-TriCB in the effluent and on the catalyst was 0.7 µg and 0.8 µg in dry and wet conditions, respectively. By calculating chorine mass balance, 35% of chlorine atoms do not present in the chlorinated compounds in the absence of water vapor. In comparsison, that value was 20% if the inlet gas stream contained water vapor. Therefore, steam can also impact the ability of the catalyst to destroy chlorinated compounds to Cl2. In terms of HeCB, there was a positive correlation between temperature and the catalytic adsorption capacity. There are currently not many scientific publications in this field, and more experiments are needed. | en_US |