Abstract:

Effects of activity (active and inactive) and existing form (aggregation state and dispersed state) of natural biofilms on the generation of H₂O₂ by the biofilms, and on the degradation of sodium dodecyl benzene sulfonate (DBS, used as a representative of degradable organic pollutant), under illumination or in darkness, were investigated through a serie of simulation experiments. Mechanisms of the H₂O₂ generation and DBS degradation by different states of natural biofilm under different conditions were also discussed. The results indicate that natural biofilms with biological activity can generate a certain amount of H₂O₂ under light or in darkness; the existing form of biofilms has an impact on both H₂O₂ generation and DBS degradation, and biofilms in aggregation state generate more H₂O₂ and degrade less DBS; light promotes not only the generation of H₂O₂ from the biofilms, but also the degradation of DBS.

Key words: light, dark, natural biofilms, degradation, hydrogen peroxide, sodium dodecyl benzene sulfonate