Nutrient balances for combined nitrification and denitrification in biofilters

摘要

Nutrient balances were set up for a biofiltration pilot operated with pre-denitrification and post-nitrification in order to gain more information about its treatment efficiency. Data collected during several weeks was used for balancing the parameters phosphorus (P_tot), carbon (COD) and nitrogen (N_tot). From the results obtained (overall deviation of 20-30percent) it can be stated that 30percent of the phosphorus load in the inlet was incorporated into biomass or sludge. The effluent contained between 50 and 80percent of the incoming phosphorus loading. The percentage of the initial carbon loading found by sludge analysis was in the range of 60 to 80percent and about 20percent were measured in the effluent. Thus, only 20 to 40percent were oxidized and/or utilized as carbon source for denitrification. The nitrogen balance showed similar values for incorportion as determined for phosphorus (20-40percent). As not more than 20percent of the incoming nitrogen load could be denitrified, 40-60percent left the plant with the effluent.