Biesterfeld Sidney, Farmer Greg, Figueroa Linda, Parker Denny, Russell Phil
Integra Engineering, 450 Decatur Street, Denver, CO 80204, USA.
Water Res. 2003 Sep;37(16):4011-7. doi: 10.1016/S0043-1354(03)00302-6.
Biofilm samples from a carbonaceous trickling filter (TF) were evaluated in bench scale reactors to determine their maximum potential denitrification rates. Intact, undisturbed biofilms were placed into 0.6 L bench-scale reactors filled with sterilized, primary clarifier effluent spiked with nitrate to a final concentration of 16-18 mg/L as N. Dissolved oxygen concentrations were maintained between 2 and 4 mg/L in the bulk aqueous phase. Nitrate loss from the reactors was monitored over a 5h period. Denitrification rates of 3.09-5.55 g-N/m(2)day were observed with no initial lag period. This suggests that the capacity for denitrification is inherent in the biofilm and that denitrification can take place even when oxygen is present in the bulk aqueous phase. There were no significant differences in denitrification rates per unit area of media (g-N/m(2)day) either between (a). experimental runs or (b). sampling locations over the trickling filter. This suggests that denitrification potentials are uniform over the entire volume of the full-scale TF. For wastewater treatment plants with TFs that currently nitrify downstream, this approach may be used to meet less stringent permitted discharge concentrations and may allow some facilities to postpone or eliminate construction of additional unit processes for denitrification.
在实验室规模的反应器中对来自碳质滴滤池（TF）的生物膜样本进行了评估，以确定其最大潜在反硝化速率。将完整、未受干扰的生物膜放入0.6升的实验室规模反应器中，该反应器装有经过消毒的初次沉淀池出水，并添加硝酸盐，使最终浓度达到16 - 18毫克/升（以氮计）。在主体水相中，溶解氧浓度维持在2至4毫克/升之间。在5小时的时间段内监测反应器中硝酸盐的损失情况。观察到反硝化速率为3.09 - 5.55克氮/平方米·天，且没有初始滞后期。这表明生物膜具有内在的反硝化能力，并且即使在主体水相中存在氧气时也能发生反硝化作用。无论是在（a）实验运行之间还是（b）滴滤池上的采样位置之间，单位面积介质的反硝化速率（克氮/平方米·天）均无显著差异。这表明全尺寸滴滤池整个体积内的反硝化潜力是均匀的。对于目前在下游进行硝化的带有滴滤池的污水处理厂，这种方法可用于满足不太严格的允许排放浓度要求，并且可能使一些设施推迟或取消额外反硝化单元工艺的建设。
