Excess Sludge Reduction in Activated Sludge Process by the Solar Photo-Fenton Reaction
Fukuda, R., Tokumura, M., Katoh, T., Znad, H.T., and Kawase, Y., Research Centre for Biochemical and Environmental Engineering, Toyo University, Japan
(free)
Excess Sludge Reduction in Activated Sludge Process by the Solar Photo-Fenton Reaction has
been investigated for the reduction of excess sludge in the activated sludge process. The
solubilization kinetics depended on the dosages of the Fenton reagents, Fe and H2O2. Increases
of initial Fe and H2O2 concentrations in their ranges studied in this work continuously enhanced
the sludge solubilization. Cell lysis by the photo-Fenton reaction caused the increase in
dissolved chemical oxygen demand (COD) in the first step of sludge solubilization. The further
oxidative decomposition of the discharged organic compounds by the photo-Fenton reaction led
the decrease in the dissolved COD as the second step of sludge solubilization. The increase of
dissolved COD in the first step of sludge solubilization and the consumption of H2O2 could be
described by the pseudo-zero order kinetics based on the accumulated light energy. About 40%
reduction of MLSS by the solar photo-Fenton reaction was found. It was found that solar light
used as a light energy source instead of costly and hazardous artificial UV light was very
effective. The dissolved COD for solar photo-Fenton reaction increased faster and by 1.5 times
as compared with that by artificial UV light.
KEY WORDS
Solubilization; excess sludge; photo-Fenton reaction; solar light; accumulated light energy
