Sarwoko Mangkoedihardjo : The Limiting Factors of Sand Bed Reactor for Heterotrophic Denitrification Process in Tropical Conditions
Prof. Dr. Ir. Sarwoko Mangkoedihardjo MScES
This research was carried out in a sand bed reactor for heterotrophic denitrification processes. A solution mixture of 24 mg nitrate-N/L and 64mg methanol-CH3OH/L was prepared for an influent of eterotrophic reactor. Influent pH level was maintained at 6.5 with the operating temperature in the range of 20 â?? 35Â°C. By adjusting nitrogen volumetric loading (NVL) and phosphorus concentrations at tropical operating conditions, it was found that the detention time in the reactor and the phosphorus concentrations of influent were the limiting factors for heterotrophic denitrification process to assure free-nitrite effluent. The maximum detention time was 1 hour and the phosphorus concentrations were 0.4 â?? 0.6 mg P/L for suppressed nitrite accumulation. The maximum NVL of 0.6 g N/day/L reactor achieved a maximum denitrification efficiency of 94%. The use of 64 mg glucose-C6H12O6/L resulted in maximum denitrification efficiency of 98%, while 64 mg acetic acid-CH3COOH/L only offered a maximum denitrification efficiency of 88%.