• KSBB Journal
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• v.21 no.4
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• pp.317-323
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• 2006

This study focused on the availability of wastewater reclamation and reusing system as one of the alternatives against the global water shortage in near future, which system is composed of two treatment steps; first, wastewater is injected into upflow $A^2O$ biofilm process(anaerobic/anoxic/oxic) reactor filled with polyethylene fixed-media, and the effluent of 1st steps continuously passed through downflow nano silver sand filter. The pH of the effluent ranged from 7.39 to 8.06(average 7.84), the $COD_{Mn}$ was $8{\sim}18mg/L$(average 12.1 mg/L), and $BOD_5$ was $2.1{\sim}10.0mg/L$(average 4.9 mg/L), that met all the wastewater reclamation and reusing system criteria. Besides, the SS concentrations of the effluent which was $3{\sim}9mg/L$(average 4.95 mg/L) met the criteria(5 mg/L), showing 94.8% of average removal efficiency. The 99.1% of the average removal efficiency of the E-coliform did not met the criteria(Not detected), which indicates the needs for the following chlorine disinfection treatment with the residual chlorine concentration of above 0.2 mg/L. There are no bacteria on the sand surface coated by nano silver. The removal efficiency of T-N and T-P that could be included into the criteria in the future was 50.3% and 27.2% respectively.

• KSBB Journal
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• v.23 no.1
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• pp.70-76
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• 2008

Surface of hydrophobic media was modified to become hydrophilic by ion beam irradiation. Fixed bed biofilm reactors packed with or without surface modification were used to remove organics, nitrogen, and phosphorus from sewage. This system composed of anoxic/oxic cycles to increase the nutrient removal. A cylindrical polyethylene was used as a packing media in this study. With 12 hours of hydraulic retention time (HRT), the reactors with and without surface modification showed 95% and 92% $COD_{cr}$ removal, respectively. Both reactors showed over 95% $COD_{cr}$ removals for a longer HRT of 16 hours. Nitrogen removal ranged 54.8% to 70.2% for the surface modified system and 57.5% to 76.5% for the non-modified system under same condition. Finally, phosphorus removal ranged 59.4% to 69.8% for the surface modified system and 51.3% to 63.4% for the non-modified system under same condition. From this study organics and phosphorus were better removed in using surface modified media and vice versa for nitrogen removal.