Photodecomposition of PCBs in aqueous systems using TiO2 as catalyst

Results are reported from preliminary experiments on the photodecomposition of polychlorinated biphenyls (Arochlor 1248) in aqueous solution, in a suspension of contaminated clay, and in a highly contaminated river sediment, using titanium dioxide as catalyst. This process destroyed almost 80 per cent of total PCB in the aqueous solution and in the clay suspension after 4 h, and about 50 per cent of PCB in the sediment suspension within 6 h. The lower chlorinated PCB congeners were decomposed more rapidly. Photocatalytic processes could be effective and low-cost methods for remediation of soils, sediment and water contaminated with PCB. Studies to improve the process were continuing.