Decomposition of dissolved organic contaminants by combining a boron-doped diamond electrode, zero-valent iron and ultraviolet radiation.

This study presents the results of a research project dealing with the degradation of dissolved tetrachloroethene, MTBE and clopyralid by using a boron-doped diamond electrode, zero-valent iron in a fluidized bed reactor and ultraviolet radiation. These treatment methods were tested alone, in any combination of two as well as in combination of all three of them to identify emerging synergy effects. Additionally, the influence of adding HO or HO + HSO is investigated. The experiments revealed that the treatment methods alone were able to decrease the organic contaminant concentrations, yet, the decomposition rate was not very sufficient. Applying the BDD yielded the highest decomposition rates, however, this degradation was accompanied by metabolite production. By combining two methods and adding HO, the decomposition was enhanced significantly for any combination. These removal rates were further increased by using the combination of the three treatment methods and adding HO or HO + HSO. These high removal rates were not achieved by solely using the combination of the three methods without further addition of chemicals. This research demonstrates the potential, but also the limitations of the investigated system.