| Abstract |
| Physicochemical pre-treatments are required to treat RO (Reverse osmosis) waste water because non-degradable organic matter and high concentrated nutrients are included in RO waste water. In this study, therefore, fenton pre-treatment process was applied to improve biodegradability and biological treatment efficiency of RO waste water. COD (Chemical oxygen demand), BOD (Biological oxygen demand), T-N (Total nitrogen), T-P (Total phosphorus), and pH of raw RO waste water were 154.4 ±27.8 mg/L, 78.9 ±19.4 mg/L, 117.0 ±21.8 mg/L, 2.0 ±0.4 mg/L, and 7.5 ±0.4, respectively. Fenton process enhanced biodegradability of RO waste water from 51% to 69%. Biological COD removal efficiencies with fenton and without fenton were 48.6 and 68.0%, respectively. Since the low COD concentration in raw RO waste water, T-N removal efficiency was not improved in MBR (Membrane bio-reactor) although fenton process was operated to improve biodegradability. These results show that the organic carbon for the biological denitrification was lacked in biodegradability improved RO waste water and the additional organic carbon was required to remove nitrogen. T-P was mainly removed by precipitation of floc formed in fenton process. The recirculation of fenton sludge without additional injection of fenton reagent was not effective to maintain pre-treatment efficiency. These result indicates that continuous injection of fenton reagent is required to maintain efficiency of fenton pre-treatment and amount of fenton reagent can be reduced by recirculation of fenton sludge. |
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| Key Words |
| Biodegradability, Fenton oxidation, Membrane bio-reactor, RO waste water |
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