| Purification of chlorobenzene by ultraviolet-biotrickling filter (UV-BTF) was studied in this paper. The light source and the biofilm carrier were an ozone producing lamp with a maximum emission (>99%) at 185nm and the ether-based polyurethane foam (PU-foam), respectively. When the residence time were 92, 69 and 46s, with the chlorobenzene concentration of 600 mg·m-3，the average removal efficiencies were 99%, 95% and 80%, respectively while the maximum removal load was 59.6 g·(m3·h)-1. The biofilm formed in the UV-BTF was 20 d, shorter than that of the sole BTF (27 d). Compared with the sole BTF, the UV-BTF had strong resistance to load shock. When the residence time was shortened to 30s, the removal efficiency of UV-BTF achieved over 75%, higher than that of sole BTF (25%). Considering the mechanism of the UV-BTF process, the UV converted the chlorobenzene into more soluble and biodegradable intermediates, thus the removal load by BTF decreased. Meanwhile, the ozone produced during the UV photolysis could control the microorganism growth in the BTF, keeping the whole system in optimal operation. |
